Investigators at the National Institute of Allergy and Infectious Diseases at the US National Institutes of Health currently have clinical protocols to study new approaches to the diagnosis and treatment of this disorder.

The old diagnostic criteria for the illness included: Chronic non-malignant lymphoproliferation, elevated peripheral blood DNTs and defective in vitro Fas mediated apoptosis.

The new criteria require chronic non-malignant lymphoproliferation (over six months lymphadenopathy and/or splenomegaly), elevated peripheral blood DNTs. A primary accessory in diagnosis is defective in vitro Fas mediated apoptosis and somatic or germline mutation in ALPS causative gene (FAS, FASL, CASP10).

The secondary accessory in diagnosis are elevated biomarkers (plasma sFASL over 200 pg/ml, plasma IL-10 >20 pg/ml, plasma or serum vitamin B12 >1500 ng/L, Plasma IL-18 >500pg/ml) and immunohistochemical findings on biopsy consistent with ALPS as determined by an experienced hematopathologist. Another sign is autoimmune cytopenias and polyclonal hypergammaglobulinemia and a family history of ALPS or non-malignant lymphoproliferation.

A definitive diagnosis is chronic non-malignant lymphoproliferation and/or elevated peripheral blood DNTs plus one primary accessory criterion. A probable diagnosis is the same but with one secondary accessory criterion.

2003 nomenclature

- IA - Fas

- IB - Fas ligand

- IIA - Caspase 10

- IIB - Caspase 8

- III - unknown

- IV - Neuroblastoma RAS viral oncogene homolog

Revised nomenclature (2010)

- ALPS-FAS: Fas. Germline FAS mutations. 70% of patients. Autosomal dominant. Dominant negative and haploinsufficient mutations described.

- ALPS-sFAS: Fas. Somatic FAS mutations in DNT compartment. 10% of patients

- ALPS-FASL: Fas ligand. Germline FASL mutations. 3 reported cases

- ALPS-CASP10: Caspase 10. Germline CASP10 mutation. 2% of patients

- ALPS-U: Undefined. 20% of patients

- CEDS: Caspase 8 deficiency state. No longer considered a subtype of ALPS but distinct disorder

- RALD: NRAS, KRAS. Somatic mutations in NRAS and KRAS in lympocyte compartment. No longer considered a subtype of ALPS but distinct disesase

The 5 year survival has been noted as 89% in at least one study from France of 201 patients with T-LGL leukemia.

There are many lymphoproliferative disorders that are associated with organ transplantation and immunosuppressant therapies. In most reported cases, these cause B cell lymphoproliferative disorders; however, some T cell variations have been described. The T cell variations are usually caused by the prolonged use of T cell suppressant drugs, such as sirolimus, tacrolimus, or ciclosporin.

Viral infection is a very common cause of lymphoproliferative disorders. In children, the most common is believed to be congenital HIV infection because it is highly associated with acquired immunodeficiency, which often leads to lymphoproliferative disorders.

XLA diagnosis usually begins due to a history of recurrent infections, mostly in the respiratory tract, through childhood. This is due to humoral immunodeficiency. The diagnosis is probable when blood tests show the complete lack of circulating B cells (determined by the B cell marker CD19 and/or CD20), as well as low levels of all antibody classes, including IgG, IgA, IgM, IgE and IgD.

When XLA is suspected, it is possible to do a Western Blot test to determine whether the Btk protein is being expressed. Results of a genetic blood test confirm the diagnosis and will identify the specific Btk mutation, however its cost prohibits its use in routine screening for all pregnancies. Women with an XLA patient in their family should seek genetic counseling before pregnancy.Although the symptoms of a XLA and other primary immune diseases (PID) include repeated and often severe infections, the average time for a diagnosis of a PID can be up to 10 years.

The current (2008) diagnostic criteria for HLH are

1. A molecular diagnosis consistent with HLH. These include the identification of pathologic mutations of PRF1, UNC13D, or STX11.

OR

2. Fulfillment of five out of the eight criteria below:

- Fever (defined as a temperature >100.4 °F, >38 °C)

- Enlargement of the spleen

- Decreased blood cell counts affecting at least two of three lineages in the peripheral blood:

- Haemoglobin <9 g/100 ml (in infants <4 weeks: haemoglobin <10 g/100 ml) (anemia)

- Platelets <100×10/L (thrombocytopenia)

- Neutrophils <1×10/L (neutropenia

- High blood levels of triglycerides (fasting, greater than or equal to 265 mg/100 ml) and/or decreased amounts of fibrinogen in the blood (≤ 150 mg/100 ml)

- Ferritin ≥ 500 ng/ml

- Haemophagocytosis in the bone marrow, spleen or lymph nodes

- Low or absent natural killer cell activity

- Soluble CD25 (soluble IL-2 receptor) >2400 U/ml (or per local reference laboratory)

In addition, in the case of familial HLH, no evidence of malignancy should be apparent.

It should be noted that not all five out of eight criteria are required for diagnosis of HLH in adults, and a high index of suspicion is required for diagnosis as delays results in increased mortality. The diagnostic criteria were developed in pediatric populations and have not been validated for adult HLH patients. Attempts to improve diagnosis of HLH have included use of the HScore, which can be used to estimate an individual's risk of HLH.

Flow cytometry is a diagnostic tool in order to count/visualize the amount of lymphatic cells in the body. T cells, B cells and NK cells are nearly impossible to distinguish under a microscope, therefore one must use a flow cytometer to distinguish them.

Clonal rearrangements of the T-cell receptor (TCR) genes are a necessary condition for the diagnosis of this disease. The gene for the β chain of the TCR is found to be rearranged more often than the γ chain. of the TCR.

Pralatrexate is one compound currently under investigations for the treatment of PTCL.

PTLD may spontaneously regress on reduction or cessation of immunosuppressant medication, and can also be treated with addition of anti-viral therapy. In some cases it will progress to non-Hodgkin's lymphoma and may be fatal. A phase 2 study of adoptively transferred EBV-specific T cells demonstrated high efficacy with minimal toxicity.

The typical patient with angioimmunoblastic T-cell lymphoma (AITL) is either middle-aged or elderly, and no gender preference for this disease has been observed. AITL comprises 15–20% of peripheral T-cell lymphomas and 1–2% of all non-Hodgkin lymphomas.

The basic tests performed when an immunodeficiency is suspected should include a full blood count (including accurate lymphocyte and granulocyte counts) and immunoglobulin levels (the three most important types of antibodies: IgG, IgA and IgM).

Other tests are performed depending on the suspected disorder:

- Quantification of the different types of mononuclear cells in the blood (i.e. lymphocytes and monocytes): different groups of T lymphocytes (dependent on their cell surface markers, e.g. CD4+, CD8+, CD3+, TCRαβ and TCRγδ), groups of B lymphocytes (CD19, CD20, CD21 and Immunoglobulin), natural killer cells and monocytes (CD15+), as well as activation markers (HLA-DR, CD25, CD80 (B cells).

- Tests for T cell function: skin tests for delayed-type hypersensitivity, cell responses to mitogens and allogeneic cells, cytokine production by cells

- Tests for B cell function: antibodies to routine immunisations and commonly acquired infections, quantification of IgG subclasses

- Tests for phagocyte function: reduction of nitro blue tetrazolium chloride, assays of chemotaxis, bactericidal activity.

Due to the rarity of many primary immunodeficiencies, many of the above tests are highly specialised and tend to be performed in research laboratories.

Criteria for diagnosis were agreed in 1999. For instance, an antibody deficiency can be diagnosed in the presence of low immunoglobulins, recurrent infections and failure of the development of antibodies on exposure to antigens. The 1999 criteria also distinguish between "definitive", "probable" and "possible" in the diagnosis of primary immunodeficiency. "Definitive" diagnosis is made when it is likely that in 20 years, the patient has a >98% chance of the same diagnosis being made; this level of diagnosis is achievable with the detection of a genetic mutation or very specific circumstantial abnormalities. "Probable" diagnosis is made when no genetic diagnosis can be made, but the patient has all other characteristics of a particular disease; the chance of the same diagnosis being made 20 years later is estimated to be 85-97%. Finally, a "possible" diagnosis is made when the patient has only some of the characteristics of a disease are present, but not all.

The blood count typically shows decreased numbers of blood cells—including a decreased amount of circulating red blood cells, white blood cells, and platelets.

The bone marrow may show hemophagocytosis.

The liver function tests are usually elevated. A low level of the protein albumin in the blood is common.

The serum C reactive protein, erythrocyte sedimentation rate, and ferritin level are markedly elevated. In children, a ferritin above 10000 is very sensitive and specific for the diagnosis of HLH, however, the diagnostic utility for ferritin is less for adult HLH patients.

The serum fibrinogen level is usually low and the D-dimer level is elevated.

The sphingomyelinase is elevated.

Bone marrow biopsy shows histiocytosis.

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.

Once a diagnosis is made, each individual's treatment is based on an individual’s clinical condition. Hematopoietic stem cell transplant is a possible treatment of this condition but its effectiveness is unproven.

Additionally, magnesium supplementation is a promising potential treatment for XMEN. One of the consequences of loss of "MAGT1" function is a decreased level of unbound intracellular Mg2+. This decrease leads to loss of expression of an immune cell receptor called "NKG2D", which is involved in EBV-immunity. Remarkably, Mg2+ supplementation can restore "NKG2D" expression and other functions that are abnormal in patients with XMEN. Early evidence suggests continuous oral magnesium threonate supplementation is safe and well tolerated. Nonetheless, further research is needed to evaluate the use of Mg2+ as a treatment for XMEN. It remains unclear if such supplementation will protect against the development of lymphoma in patients with XMEN. Investigators at the National Institute of Allergy and Infectious Diseases at the US National Institutes of Health currently have clinical protocols to study new approaches to the diagnosis and treatment of this disorder.

RALD patients show normal to modestly decreased total lymphocytes, mild to no elevation in αβ-double negative T cells, a relative expansion of B cells, and elevated granulocytes and monocytes. The absolute or relative monocytosis in particular is an important characteristic of this disorder and help differentiate it from ALPS. Autoantibodies are also common.

MBL has been found in less than 1% of asymptomatic adults under age 40, and in around 5% of adults older than 60. Exact numbers depend on the population studied and the sensitivity of the diagnostic technique.

Like CLL, it appears to be more common in males.

It is also a common finding among older adults with unexplained lymphocytosis.

Recent studies suggest that CLL is very often preceded by MBL,

and that MBL progresses to CLL requiring treatment at a rate of around 1-2% per year. Advancing age and high initial B cell count predispose to progression from MBL to CLL; however, only a small fraction of people with MBL die because of CLL.

Thus, MBL could be regarded as a premalignant condition from which some cases progress to CLL (much similar to the progression of some cases of monoclonal gammopathy of undetermined significance to multiple myeloma).

No treatment is required, but follow-up might be able to detect new diagnoses of CLL. However, this might lead to increased costs, repeated investigations, unnecessary anxiety about cancer and health insurance concerns, while there is no means to prevent progression to CLL.

Serology (detection on antibodies to a specific pathogen or antigen) is often used to diagnose viral diseases. Because XLA patients lack antibodies, these tests always give a negative result regardless of their real condition. This applies to standard HIV tests. Special blood tests (such as the western blot based test) are required for proper viral diagnosis in XLA patients.

It is not recommended and dangerous for XLA patients to receive live attenuated vaccines such as live polio, or the measles, mumps, rubella (MMR vaccine). Special emphasis is given to avoiding the oral live attenuated SABIN-type polio vaccine that has been reported to cause polio to XLA patients. Furthermore, it is not known if active vaccines in general have any beneficial effect on XLA patients as they lack normal ability to maintain immune memory.

XLA patients are specifically susceptible to viruses of the Enterovirus family, and mostly to: polio virus, coxsackie virus (hand, foot, and mouth disease) and Echoviruses. These may cause severe central nervous system conditions as chronic encephalitis, meningitis and death. An experimental anti-viral agent, pleconaril, is active against picornaviruses. XLA patients, however, are apparently immune to the Epstein-Barr virus (EBV), as they lack mature B cells (and so HLA co-receptors) needed for the viral infection. Patients with XLA are also more likely to have a history of septic arthritis.

It is not known if XLA patients are able to generate an allergic reaction, as they lack functional IgE antibodies.There is no special hazard for XLA patients in dealing with pets or outdoor activities. Unlike in other primary immunodeficiencies XLA patients are at no greater risk for developing autoimmune illnesses.

Agammaglobulinemia (XLA) is similar to the primary immunodeficiency disorder Hypogammaglobulinemia (CVID), and their clinical conditions and treatment are almost identical. However, while XLA is a congenital disorder, with known genetic causes, CVID may occur in adulthood and its causes are not yet understood.

XLA was also historically mistaken as Severe Combined Immunodeficiency (SCID), a much more severe immune deficiency ("Bubble boys").A strain of laboratory mouse, XID, is used to study XLA. These mice have a mutated version of the mouse Btk gene, and exhibit a similar, yet milder, immune deficiency as in XLA.

Diagnosing ALL begins with a thorough medical history, physical examination, complete blood count, and blood smears. While many symptoms of ALL can be found in common illnesses, persistent or unexplained symptoms raise suspicion of cancer. Because many features on the medical history and exam are not specific to ALL, further testing is often needed. A large number of white blood cells and lymphoblasts in the circulating blood can be suspicious for ALL because they indicate a rapid production of lymphoid cells in the marrow. The higher these numbers typically points to a worse prognosis. While white blood cell counts at initial presentation can vary significantly, circulating lymphoblast cells are seen on peripheral blood smears in the majority of cases.

A bone marrow biopsy provides conclusive proof of ALL, typically with >20% of all cells being leukemic lymphoblasts. A lumbar puncture (also known as a spinal tap) can determine whether the spinal column and brain have been invaded. Brain and spinal column involvement can be diagnosed either through confirmation of leukemic cells in the lumbar puncture or through clinical signs of CNS leukemia as described above. Laboratory tests that might show abnormalities include blood count, kidney function, electrolyte, and liver enzyme tests.

Pathological examination, cytogenetics (in particular the presence of Philadelphia chromosome), and immunophenotyping establish whether the leukemic cells are myeloblastic (neutrophils, eosinophils, or basophils) or lymphoblastic (B lymphocytes or T lymphocytes). Cytogenetic testing on the marrow samples can help classify disease and predict how aggressive the disease course will be. Different mutations have been associated with shorter or longer survival. Immunohistochemical testing may reveal TdT or CALLA antigens on the surface of leukemic cells. TdT is a protein expressed early in the development of pre-T and pre-B cells, whereas CALLA is an antigen found in 80% of ALL cases and also in the "blast crisis" of CML.

Medical imaging (such as ultrasound or CT scanning) can find invasion of other organs commonly the lung, liver, spleen, lymph nodes, brain, kidneys, and reproductive organs.

There is currently minimal therapeutic intervention available for BENTA disease. Patients are closely monitored for infections and for signs of monoclonal or oligoclonal B cell expansion that could indicate B cell malignancy. Splenectomy is unlikely to reduce B cell burden; peripheral blood B cell counts rose significantly in three patients who underwent the procedure. It remains to be determined whether immunosuppressive drugs, including B cell-depleting drugs such as rituximab, could be effective for treating BENTA disease.

Cytogenetic analysis has shown different proportions and frequencies of genetic abnormalities in cases of ALL from different age groups. This information is particularly valuable for classification and can in part explain different prognosis of these groups. In regards to genetic analysis, cases can be stratified according to ploidy, number of sets of chromosomes in the cell, and specific genetic abnormalities, such as translocations. Hyperdiploid cells are defined as cells with more than 50 chromosomes, while hypodiploid is defined as cells with less than 44 choromosomes. Hyperdiploid cases tend to carry good prognosis while hypodiploid cases do not. For example, the most common specific abnormality in childhood B-ALL is the t(12;21) "ETV6"-"RUNX1" translocation, in which the "RUNX1" gene, encoding a protein involved in transcriptional control of hemopoiesis, has been translocated and repressed by the "ETV6"-"RUNX1" fusion protein.

Below is a table with the frequencies of some cytogenetic translocations and molecular genetic abnormalities in ALL.

The disease is an uncontrolled proliferation of B cell lymphocytes latently infected with Epstein-Barr virus. Production of an interleukin-10, an endogenous, pro-regulatory cytokine, has also been implicated.

In immunocompetent patients, Epstein-Barr virus can cause infectious mononucleosis in adolescents, which is otherwise asymptomatic in children during their childhood. However, in immunosuppressed transplant patients, the lack of T-cell immunosurveillance can lead to the proliferation of these EBV-infected of B-lymphocytes.

However, calcineurin inhibitors (tacrolimus and ciclosporin), used as immunosuppressants in organ transplantation inhibit T cell function, and can prevent the control of the B cell proliferation.

Depletion of T cells by use of anti-T cell antibodies in the prevention or treatment of transplant rejection further increases the risk of developing post-transplant lymphoproliferative disorder. Such antibodies include ATG, ALG and OKT3.

Polyclonal PTLD may form tumor masses and present with symptoms due to a mass effect, e.g. symptoms of bowel obstruction. Monoclonal forms of PTLD tend to form a disseminated malignant lymphoma.

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.