Intravenously administered glucocorticoids, such as prednisone, are the standard of care in acute GvHD and chronic GVHD. The use of these glucocorticoids is designed to suppress the T-cell-mediated immune onslaught on the host tissues; however, in high doses, this immune-suppression raises the risk of infections and cancer relapse. Therefore, it is desirable to taper off the post-transplant high-level steroid doses to lower levels, at which point the appearance of mild GVHD may be welcome, especially in HLA mis-matched patients, as it is typically associated with a graft-versus-tumor effect.. Cyclosporine and tacrolimus are inhibitors of calcineurin. Both substances are structurally different but have the same mechanism of action. Cyclosporin binds to the cytosolic protein Peptidyl-prolyl cis-trans isomerase A (known as cyclophilin), while tacrolimus binds to the cytosolic protein Peptidyl-prolyl cis-trans isomerase FKBP12. These complexes inhibit calcineurin, block dephosphorylation of the transcription factor NFAT of activated T-cells and its translocation into the nucleus. Standard prophylaxis involves the use of cyclosporine for six months with methotrexate. Cyclosporin levels should be maintained above 200 ng/ml.

Other substances that have been studied for GvHD prophylaxis include, for example: sirolimus, pentostatin and alemtuzamab.

In August 2017 the US FDA approved ibrutinib to treat chronic GvHD after failure of one or more other systemic treatments.

There are a large number of clinical trials either ongoing or recently completed in the investigation of graft-versus-host disease treatment and prevention. Currently, there are no reliable molecular markers reflecting the onset or clinical course of aGVHD. However, it has been shown that genes responsible for cytokine signaling, inflammatory response, and regulation of cell cycle are differentially expressed in patinets with fatal GvHD versus „indolent“ GvHD.

On May 17, 2012, Osiris Therapeutics announced that Canadian health regulators approved Prochymal, its drug for acute graft-versus host disease in children who have failed to respond to steroid treatment. Prochymal is the first stem cell drug to be approved for a systemic disease.

In January 2016, Mesoblast released results of a Phase2 clinical trial on 241 children with acute Graft-versus-host disease, that was not responsive to steroids. The trial was of a mesenchymal stem cell therapy known as remestemcel-L or MSC-100-IV. Survival rate was 82% (vs 39% of controls) for those who showed some improvement after 1 month, and in the long term 72% (vs 18% of controls) for those that showed little effect after 1 month.

Azathioprine is a steroid-sparing agent used in combination with Prednisone. It functions by inhibiting RNA and DNA synthesis.

Prednisone is an immunosuppressive agent which affects all of the organ systems. Effects on the cellular level include cell activation, replication, differentiation, and mobility. The overall goal is to decrease blistering (inhibition of immediate and delayed hypersensitivity) through decreasing the production of autoantibodies. In order to suppress the production of antibodies, higher doses must be administered. Lesser doses can be prescribed in order to achieve suppression of monocyte function.

The treatment of primary immunodeficiencies depends foremost on the nature of the abnormality. Somatic treatment of primarily genetic defects is in its infancy. Most treatment is therefore passive and palliative, and falls into two modalities: managing infections and boosting the immune system.

Reduction of exposure to pathogens may be recommended, and in many situations prophylactic antibiotics or antivirals may be advised.

In the case of humoral immune deficiency, immunoglobulin replacement therapy in the form of intravenous immunoglobulin (IVIG) or subcutaneous immunoglobulin (SCIG) may be available.

In cases of autoimmune disorders, immunosuppression therapies like corticosteroids may be prescribed.

Bone marrow transplant may be possible for Severe Combined Immune Deficiency and other severe immunodeficiences.

Virus-specific T-Lymphocytes (VST) therapy is used for patients who have received hematopoietic stem cell transplantation that has proven to be unsuccessful. It is a treatment that has been effective in preventing and treating viral infections after HSCT. VST therapy uses active donor T-cells that are isolated from alloreactive T-cells which have proven immunity against one or more viruses. Such donor T-cells often cause acute graft-versus-host disease (GVHD), a subject of ongoing investigation. VSTs have been produced primarily by ex-vivo cultures and by the expansion of T-lymphocytes after stimulation with viral antigens. This is carried out by using donor-derived antigen-presenting cells. These new methods have reduced culture time to 10–12 days by using specific cytokines from adult donors or virus-naive cord blood. This treatment is far quicker and with a substantially higher success rate than the 3–6 months it takes to carry out HSCT on a patient diagnosed with a primary immunodeficiency. T-lymphocyte therapies are still in the experimental stage; few are even in clinical trials, none have been FDA approved, and availability in clinical practice may be years or even a decade or more away.

Patients often have a refractory disease course but some patients may respond to phototherapy.

Treatment depends on the grade (I-III) but typically consist of cortisone, rituximab and chemotherapy (etoposide, vincristine, cyclophosphamide, doxorubicin). Methotrexate has been seen to induce LYG. Interferon alpha has been used by the US National Cancer Institute with varying results. In recent years hematopoietic stem cell transplantation has been performed on LYG-patients with relative good success; a 2013 study identifying 10 cases found that 8 patients survived the treatment and were disease free several years later. Two of the disease free patients later died, one from suicide and one from graft versus host disease after a second transplantation 4 years later. The remaining two patients died from sepsis after the transplantation.

Some types of arthritis medications are designed to reduce inflammation by inhibiting the tumor necrosis factor-alpha pathway to immune cell activation; these drugs are known as TNF-alpha blockers. One study found that three different TNF-alpha blockers afforded a slight reduction in antibody presentation after vaccination against influenza in a group of immunocompromised patients, however it did not significantly affect patients' protective factor gained from inoculation. More research is necessary before any conclusions may be made regarding the efficacy of TNF-alpha blockers at reducing the effects of a cytokine storm in hospitalized flu patients.

Although frequently employed to treat patients experiencing the cytokine storm associated with ARDS, corticosteroids and NSAIDs have been evaluated in clinical trials and have shown no effect on lung mechanics, gas exchange, or beneficial outcome in early established ARDS.

The only treatment for Omenn syndrome is chemotherapy followed by a bone marrow transplantation. Without treatment, it is rapidly fatal in infancy.

Treatment for X-linked SCID can be divided into two main groups, the prophylactic treatment (i.e. preventative) and curative treatment. The former attempts to manage the opportunistic infections common to SCID patients and the latter aims at reconstituting healthy T-lymphocyte function.

From the late 60s to early 70s, physicians began using "bubbles", which were plastic enclosures used to house newborns suspected to have SCIDS, immediately after birth. The bubble, a form of isolation, was a sterile environment which meant the infant would avoid infections caused by common and lethal pathogens. On the other hand, prophylactic treatments used today for X-linked SCID are similar to those used to treat other primary immunodeficiencies. There are three types of prophylactic treatments, namely, the use of medication, sterile environments, and intravenous immunoglobulin therapy (IVIG). First, antibiotics or antivirals are administered to control opportunistic infections, such as fluconazole for candidiasis, and acyclovir to prevent herpes virus infection. In addition, the patient can also undergo intravenous immunoglobulin (IVIG) supplementation. Here, a catheter is inserted into the vein and a fluid, containing antibodies normally made by B-cells, is injected into the patient's body. Antibodies, Y-shaped proteins created by plasma cells, recognize and neutralize any pathogens in the body. However, the IVIG is expensive, in terms of time and finance. Therefore, the aforementioned treatments only prevent the infections, and are by no means a cure for X-linked SCID.

Bone marrow transplantation (BMT) is a standard curative procedure and results in a full immune reconstitution, if the treatment is successful. Firstly, a bone marrow transplant requires a human leukocyte antigen (HLA) match between the donor and the recipient. The HLA is distinct from person to person, which means the immune system utilizes the HLA to distinguish self from foreign cells. Furthermore, a BMT can be allogenic or autologous, which means the donor and recipient of bone marrow can be two different people or the same person, respectively. The autologous BMT involves a full HLA match, whereas, the allogenic BMT involves a full or half (haploidentical) HLA match. Particularly, in the allogenic BMT the chances of graft-versus-host-disease occurring is high if the match of the donor and recipient is not close enough. In this case, the T-cells in the donor bone marrow attack the patient's body because the body is foreign to this graft. The depletion of T-cells in the donor tissue and a close HLA match will reduce the chances of graft-versus-host disease occurring. Moreover, patients who received an exact HLA match had normal functioning T-cells in fourteen days. However, those who received a haploidentical HLA match, their T-cells started to function after four months. In addition, the reason BMT is a permanent solution is because the bone marrow contains multipotent hematopoietic stem cells which become common lymphoid or common myeloid progenitors. In particular, the common lymphoid progenitor gives rise to the lymphocytes involved in the immune response (B-cell, T-cell, natural killer cell). Therefore, a BMT will result in a full immune reconstitution but there are aspects of BMT that need to be improved (i.e. GvHD).

Gene therapy is another treatment option which is available only for clinical trials. X-linked SCID is a monogenic disorder, the IL2RG gene is mutated, so gene therapy will replace this mutated gene with a normal one. This will result in a normal functioning gamma chain protein of the interleukin receptor. In order to transfer a functional gene into the target cell, viral or non-viral vectors can be employed. Viral vectors, such as the retrovirus, that incorporate the gene into the genome result in long-term effects. This, coupled with the bone marrow stem cells, has been successful in treating individuals with X-SCID. In one particular trial by Cavazzana-Calvo et al., ten children were treated with gene therapy at infancy for X-SCID. Nine of the ten were cured of X-SCID. However, about three years after treatment, two of the children developed T-cell leukemia due to insertion of the IL2RG gene near the LMO2 gene and thereby activating the LMO2 gene (a known oncogene). A third child developed leukemia within two years of that study being published, likely as a direct result of the therapy. This condition is known as insertional mutagenesis, where the random insertion of a gene interferes with the tumor suppressor gene or stimulates an oncogene. There is currently no approved gene therapy on the market, but there are many clinical trials into which X-SCID patients may enroll. Therefore, research in the field of gene therapy today and in the future is needed to avoid the occurrence of leukemia. In particular, research into the use of insulator and suicide genes is warranted as this may prevent cancer from developing. The insulator gene inhibits the activation of adjacent genes. On the other hand, the suicide gene is stimulated when a tumour begins to form, and this will result in the deactivation of the therapeutic gene. Moreover, the use of restriction enzymes such as the zinc-finger nuclease (ZFN) is being studied. The ZFN allows the researcher to choose the site of gene integration. Vector safety is important in the field of gene therapy, hence vectors that self-inactivate the promoter and enhancer (SIN) and adenoviruses that creates no immune response are prominent areas of research for vector biologists.

The most common treatment for SCID is bone marrow transplantation, which has been successful using either a matched related or unrelated donor, or a half-matched donor, who would be either parent. The half-matched type of transplant is called haploidentical. Haploidentical bone marrow transplants require the donor marrow to be depleted of all mature T cells to avoid the occurrence of graft-versus-host disease (GVHD). Consequently, a functional immune system takes longer to develop in a patient who receives a haploidentical bone marrow transplant compared to a patient receiving a matched transplant. David Vetter, the original "bubble boy", had one of the first transplantations, but eventually died because of an unscreened virus, Epstein-Barr (tests were not available at the time), in his newly transplanted bone marrow from his sister, an unmatched bone marrow donor. Today, transplants done in the first three months of life have a high success rate. Physicians have also had some success with "in utero" transplants done before the child is born and also by using cord blood which is rich in stem cells. "In utero" transplants allow for the fetus to develop a functional immune system in the sterile environment of the uterus; however complications such as GVHD would be difficult to detect or treat if they were to occur.

More recently gene therapy has been attempted as an alternative to the bone marrow transplant. Transduction of the missing gene to hematopoietic stem cells using viral vectors is being tested in ADA SCID and X-linked SCID. In 1990, four-year-old Ashanthi DeSilva became the first patient to undergo successful gene therapy. Researchers collected samples of DeSilva's blood, isolated some of her white blood cells, and used a retrovirus to insert a healthy adenosine deaminase (ADA) gene into them. These cells were then injected back into her body, and began to express a normal enzyme. This, augmented by weekly injections of ADA, corrected her deficiency. However, the concurrent treatment of ADA injections may impair the success of gene therapy, since transduced cells will have no selective advantage to proliferate if untransduced cells can survive in the presence of the injected ADA.

In 2000, a gene therapy "success" resulted in SCID patients with a functional immune system. These trials were stopped when it was discovered that two of ten patients in one trial had developed leukemia resulting from the insertion of the gene-carrying retrovirus near an oncogene. In 2007, four of the ten patients have developed leukemias. Work aimed at improving gene therapy is now focusing on modifying the viral vector to reduce the likelihood of oncogenesis and using zinc-finger nucleases to more specifically target gene insertion. No leukemia cases have yet been seen in trials of ADA-SCID, which does not involve the "gamma c" gene that may be oncogenic when expressed by a retrovirus.

Trial treatments of SCID have been gene therapy's first success; since 1999, gene therapy has restored the immune systems of at least 17 children with two forms (ADA-SCID and X-SCID) of the disorder.

There are also some non-curative methods for treating SCID. Reverse isolation involves the use of laminar air flow and mechanical barriers (to avoid physical contact with others) to isolate the patient from any harmful pathogens present in the external environment. A non-curative treatment for patients with ADA-SCID is enzyme replacement therapy, in which the patient is injected with polyethyleneglycol-coupled adenosine deaminase (PEG-ADA) which metabolizes the toxic substrates of the ADA enzyme and prevents their accumulation. Treatment with PEG-ADA may be used to restore T cell function in the short term, enough to clear any existing infections before proceeding with curative treatment such as a bone marrow transplant.

X-linked SCID is a known pediatric emergency which primarily affects males. If the appropriate treatment such as intravenous immunoglobulin supplements, medications for treating infections or a bone marrow transplant is not administered, then the prognosis is poor. The patients with X-linked SCID usually die two years after they are born. For this reason, the diagnosis of X-linked SCID needs to be done early to prevent any pathogens from infecting the infant.

However, the patients have a higher chance of survival if the diagnosis of X-linked SCID is done as soon as the baby is born. This involves taking preventative measures to avoid any infections that can cause death. For example, David Vetter had a high chance of having X-linked SCID because his elder sibling had died due to SCID. This allowed the doctors to place David in the bubble and prevented infections. In addition, if X-linked SCID is known to affect a child, then live vaccines should not be administered and this can save the infants life. Vaccines, which are pathogens inserted into the body to create an immune response, can lead to death in infants with X-linked SCID. Moreover, with proper treatments, such as a bone marrow transplant, the prognosis is good. The bone marrow transplant has been successful in treating several patients and resulted in a full immune reconstitution and the patient can live a healthy life. The results of bone marrow transplant are most successful when the closest human leukocyte antigen match has been found. If a close match is not found, however, there is a chance of graft-versus-host-disease which means the donor bone marrow attacks the patient's body. Hence, a close match is required to prevent any complications.

Due to its rarity, no comprehensive treatment studies on eosinophilic myocarditis have been conducted. Small studies and case reports have directed efforts towards: a) supporting cardiac function by relieving heart failure and suppressing life-threatening abnormal heart rhythms; b) suppressing eosinophil-based cardiac inflammation; and c) treating the underlying disorder. In all cases of symptomatic eosinophilic myocarditis that lack specific treatment regimens for the underlying disorder, available studies recommend treating the inflammatory component of this disorder with non-specific immunosuppressive drugs, principally high-dosage followed by slowly-tapering to a low-dosage maintenance corticosteroid regimens. It is recommended that afflicted individuals who fail this regimen or present with cardiogenic shock be treated with other non-specific immunosuppressive drugs viz., azathioprine or cyclophosphamide, as adjuncts to, or replacements for, corticosteroids. However, individuals with an underlying therapeutically accessible disease should be treated for this disease; in seriously symptomatic cases, such individuals may be treated concurrently with a corticosteroid regimen. Examples of diseases underlying eosinophilic myocarditis that are recommended for treatments directed at the underlying disease include:

- Infectious agents: specific drug treatment of helminth and protozoan infections typically takes precedence over non-specific immunosuppressive therapy, which, if used without specific treatment, could worsen the infection. In moderate-to-severe cases, non-specific immunosuppression is used in combination with specific drug treatment.

- Toxic reactions to ingested agents: discontinuance of the ingested agent plus corticosteroids or other non-specific immunosuppressive regimens.

- Clonal eosinophilia caused by mutations in genes that are highly susceptible to tyrosine kinase inhibitors such as "PDGFRA", "PDGFRB", or possibly "FGFR1": first generation tyrosine kinase inhibitors (e.g. imatinib) are recommended for the former two mutations; a later generation tyrosine kinase inhibitors, ponatinib, alone or combined with bone marrow transplantation, may be useful for treating the FGFR1 mutations.

- Clonal hypereosinophilia due to mutations in other genes or primary malignancies: specific treatment regimens used for these pre-malignant or malignant diseases may be more useful and necessary than non-specific immunosuppression.

- Allergic and autoimmune diseases: non-specific treatment regimens used for these diseases may be useful in place of a simple corticosteroid regimen. For example, eosinophilic granulomatosis with polyangiitis can be successfully treated with mepolizumab.

- Idiopathic hypereosinphilic syndrome and lymphocyte-variant hypereosinophilia: corticosteroids; for individuals with these hypereosinophilias that are refractory to or break through corticosteroid therapy and individuals requiring corticosteroid-sparing therapy, recommended alternative drug therapies include hydroxyurea, Pegylated interferon-α, and either one of two tyrosine kinase inhibitors viz., imatinib and mepolizumab).

There is no cure for scleroderma, although relief of symptoms is often achieved. These include

- Raynaud's phenomenon with vasodilators such as calcium channel blockers, alpha blockers, serotonin receptor antagonists, angiotensin II receptor inhibitors, statins, local nitrates or iloprost

- Digital ulcers with phosphodiesterase 5 inhibitors (e.g., sildenafil) or iloprost

- Prevention of new digital ulcers with bosentan

- Malnutrition, secondary to intestinal flora overgrowth with tetracycline antibiotics like tetracycline

- Alveolitis with cyclophosphamide, azathioprine with or without corticosteroids

- Pulmonary arterial hypertension with endothelin receptor antagonists, phosphodiesterase 5 inhibitors and prostanoids

- Gastrooesophageal reflux disease with antacids or prokinetics

- Kidney crises with angiotensin converting enzyme inhibitors and angiotensin II receptor antagonists

Systemic disease-modifying treatment with immunosuppressants is often used. Immunosuppressants used in its treatment include azathioprine, methotrexate, cyclophosphamide, mycophenolate, intravenous immunoglobulin, rituximab, sirolimus, alefacept and the tyrosine kinase inhibitors, imatinib, nilotinib and dasatinib.

Experimental therapies under investigation include endothelin receptor antagonsits, tyrosine kinase inhibitors, beta-glycan peptides, halofuginone, basiliximab, alemtuzumab, abatacept and haematopoietic stem cell transplantation.

This disease entitiy was described in detail in 2007 but case reports of graft-versus-host-like disease in the setting of thymoma date back to at least the mid 1990's.

The current mortality is over 60% after 5 years. However, due to hematopoietic stem cell transplantation being performed only in recent years, this number could potentially be lowered in the future. In patients with CNS involvement, treatment with Interferon alpha at US National Cancer Institute resulted in complete remission in 90% of patients.

The main treatment for acral erythema is discontinuation of the offending drug, and symptomatic treatment to provide analgesia, lessen edema, and prevent superinfection. However, the treatment for the underlying cancer of the patient must not be neglected. Often, the discontinued drug can be substituted with another cancer drug or cancer treatment.

Symptomatic treatment can include wound care, elevation, and pain medication. Corticosteroids and pyridoxine have also been used to relieve symptoms. Other studies do not support the conclusion.

A number of additional remedies are listed in recent medical literature. Among them henna and 10% uridine ointment which went through clinical trial.

Treatment is not necessary since the lesion is benign, however the person may have esthetic concerns about the appearance. The condition often resolves rapidly with high dose acyclovir or desiclovir but recurs once this therapy is stopped, or as the underlying immunocompromise worsens. Topical use of podophyllum resin or retinoids has also been reported to produce temporary remission. Antiretroviral drugs such as zidovudine may be effective in producing a significant regression of OHL. Recurrence of the lesion may also signify that highly active antiretroviral therapy (HAART) is becoming ineffective.

The course of treatment and the success rate is dependent on the type of TMA. Some patients with atypical HUS and TTP have responded to plasma infusions or exchanges, a procedure which replaces proteins necessary for the complement cascade that the patient does not have; however, this is not a permanent solution or treatment, especially for patients with congenital predispositions.

PPE invariably recurs with the resumption of chemotherapy. Long-term chemotherapy may also result in reversible palmoplantar keratoderma. Symptoms resolve 1–2 weeks after cessation of chemotherapy (Apisarnthanarax and Duvic 2003).

Cordocentesis can be performed in utero to determine the platelet count of the fetus. This procedure is only performed if a "prior" pregnancy was affected by . Intrauterine transfusions can be performed during cordocentesis for primary prevention of intracerebral hemorrhage. Any administered cellular blood products must be irradiated to reduce the risk of graft-versus-host disease in the fetus. Additionally, all administered blood products should be reduced-risk ( seronegative and leukoreduced are considered essentially equivalent for the purposes of risk reduction).

If intrauterine platelet transfusions are performed, they are generally repeated weekly (platelet lifespan after transfusion is approximately 8 to 10 days). Platelets administered to the fetus must be negative for the culprit antigen (often -1a, as stated above). Many blood suppliers (such as American Red Cross and United Blood Services) have identified -1a negative donors. An alternative donor is the mother who is, of course, negative for the culprit antigen. However, she must meet general criteria for donation and platelets received from the mother must be washed to remove the offending alloantibody and irradiated to reduce the risk of graft-versus-host disease. If platlet transfusions are needed urgently, incompatible platelets may be used, with the understanding that they may be less effective and that the administration of any blood product carries risk.

The use of Intravenous immunoglobulin () during pregnancy and immediately after birth has been shown to help reduce or alleviate the effects of in infants and reduce the severity of thrombocytopenia. The most common treatment is weekly infusions at a dosage of 1 g/kg beginning at 16 to 28 weeks of pregnancy, depending on the severity of the disease in the previous affected child, and continuing until the birth of the child. In some cases this dosage is increased to 2 g/kg and/or combined with a course of prednisone depending on the exact circumstances of the case. Although this treatment has not been shown to be effective in all cases it has been shown to reduce the severity of thrombocytopenia in some. Also, it is suspected that (though not understood why) provides some added protection from intercranial haemorrhage () to the fetus. Even with treatment, the fetal platelet count may need to be monitored and platelet transfusions may still be required.

The goal of both and platelet transfusion is to avoid hemorrhage. Ultrasound monitoring to detect hemorrhage is not recommended as detection of intracranial hemorrhage generally indicates permanent brain damage (there is no intervention that can be performed to reverse the damage once it has occurred).

Before delivery, the fetal platelet count should be determined. A count of >50,000 μL is recommended for vaginal delivery and the count should be kept above 20,000 μL after birth.

The cornerstone of therapy is reduction in immunosuppression. A recent surge in BKVAN correlates with use of potent immunosuppressant drugs, such as tacrolimus and mycophenolate mofetil (MMF). Studies have not shown any correlation between BKVAN and a single immunosuppressive agent but rather the overall immunosuppressive load.

- No guidelines or drug levels and doses exist for proper reduction of immunosuppressants in BKVAN

- Most common methods:

1. Withdrawal of MMF or tacrolimus

2. Replacement of tacrolimus by cyclosporine

3. Overall reduction of immunosuppressive load

4. Some cyclosporine trough levels reported to be reduced to 100–150 ng/ml and tacrolimus levels reduced to 3–5 ng/ml

- Retrospective analysis of 67 patients concluded graft survival was similar between reduction and discontinuation of agents.

- Single center study showed renal allografts were preserved in 8/8 individuals managed with reduction in immunosuppression while graft loss occurred in 8/12 patients treated with an increase in therapy for what was thought to be organ rejection.

Other therapeutic options include Leflunomide, Cidofovir, IVIG, and the fluoroquinolones. Leflunomide, a pyrimidine synthesis inhibitor is now generally accepted as the second treatment option behind reduction of immunosuppression.

Treating immune-mediated aplastic anemia involves suppression of the immune system, an effect achieved by daily medicine intake, or, in more severe cases, a bone marrow transplant, a potential cure. The transplanted bone marrow replaces the failing bone marrow cells with new ones from a matching donor. The multipotent stem cells in the bone marrow reconstitute all three blood cell lines, giving the patient a new immune system, red blood cells, and platelets. However, besides the risk of graft failure, there is also a risk that the newly created white blood cells may attack the rest of the body ("graft-versus-host disease"). In young patients with an HLA matched sibling donor, bone marrow transplant can be considered as first-line treatment, patients lacking a matched sibling donor typically pursue immunosuppression as a first-line treatment, and matched unrelated donor transplants are considered a second-line therapy.

Medical therapy of aplastic anemia often includes a course of antithymocyte globulin (ATG) and several months of treatment with ciclosporin to modulate the immune system. Chemotherapy with agents such as cyclophosphamide may also be effective but has more toxicity than ATG. Antibody therapy, such as ATG, targets T-cells, which are believed to attack the bone marrow. Corticosteroids are generally ineffective, though they are used to ameliorate serum sickness caused by ATG. Normally, success is judged by bone marrow biopsy 6 months after initial treatment with ATG.

One prospective study involving cyclophosphamide was terminated early due to a high incidence of mortality, due to severe infections as a result of prolonged neutropenia.

In the past, before the above treatments became available, patients with low leukocyte counts were often confined to a sterile room or bubble (to reduce risk of infections), as in the case of Ted DeVita.