Generally, patients with febrile neutropenia are treated with empirical antibiotics until the neutrophil count has recovered (absolute neutrophil counts greater than 500/mm) and the fever has abated; if the neutrophil count does not improve, treatment may need to continue for two weeks or occasionally more. In cases of recurrent or persistent fever, an antifungal agent should be added.

Guidelines issued in 2002 by the Infectious Diseases Society of America recommend the use of particular combinations of antibiotics in specific settings; mild low-risk cases may be treated with a combination of oral amoxicillin-clavulanic acid and ciprofloxacin, while more severe cases require cephalosporins with activity against "Pseudomonas aeruginosa" (e.g. cefepime), or carbapenems (imipenem or meropenem). A subsequent meta-analysis published in 2006 found cefepime to be associated with more negative outcomes, and carbapenems (while causing a higher rate of pseudomembranous colitis) were the most straightforward in use.

In 2010, updated guidelines were issued by the Infectious Diseases Society of America, recommending use of cefepime, carbapenems (meropenem and imipenem/cilastatin), or piperacillin/tazobactam for high-risk patients and amoxicillin-clavulanic acid and ciprofloxacin for low-risk patients. Patients who do not strictly fulfill the criteria of low-risk patients should be admitted to the hospital and treated as high-risk patients.

The Multinational Association for Supportive Care in Cancer (MASCC) risk index can be used to identify low-risk patients (score ≥21 points) for serious complications of febrile neutropenia (including death, intensive care unit admission, confusion, cardiac complications, respiratory failure, renal failure, hypotension, bleeding, and other serious medical complications). The score was developed to select patients for therapeutic strategies that could potentially be more convenient or cost-effective. A prospective trial demonstrated that a modified MASCC score can identify patients with febrile neutropenia at low risk of complications, as well.

In contrast, the Clinical Index of Stable Febrile Neutropenia (CISNE) score is specific of patients with solid tumors and seemingly stable episodes. CISNE is able to discriminate groups of patients who are at low, intermediate, and high risk of complications in this population. With the CISNE, the complication rate was determined to be 1.1% for low-risk patients, 6.2% for intermediate-risk patients, and 36.0% for high-risk patients. The prime purpose of this model was to avoid complications from an early hospital release. On the contrary, CISNE should not be used so much to select low-risk patients for outpatient treatment.

Recombinant granulocyte-colony stimulating factor preparations, such as filgrastim can be effective in patients with congenital forms of neutropenia including severe congenital neutropenia and cyclic neutropenia, the amount needed (dosage) varies considerably (depending on the individual's condition) to stabilize the neutrophil count. Guidelines for neutropenia regarding diet are currently being studied.

Most cases of neonatal neutropenia are temporary. Antibiotic prophylaxis is not recommended because of the possibility of encouraging the development of multidrug-resistant bacterial strains.

Neutropenia can be treated with hematopoietic Growth Factors, granulocyte-colony stimulating factor (G-CSF) or granulocyte-macrophage colony-stimulating factor (GM-CSF). These are cytokines (inflammation-inducing chemicals) that are present naturally in the body. These factors are used regularly in cancer treatment with adults and children. The factors promote neutrophil recovery following anticancer therapy.

The administration of intravenous immunoglobulins (IVIGs) has had some success in treating neutropenias of alloimmune and autoimmune origins with a response rate of about 50%. Blood transfusions have not been effective.

If left untreated, patients with fever and absolute neutrophil count <500 have a mortality of up to 70% within 24 hours. The prognosis of neutropenia depends on the cause. Antibiotic agents have improved the prognosis for individuals with severe neutropenia. Neutropenic fever in individuals treated for cancer has a mortality of 4-30%.

This form usually lessens in severity within two years of diagnosis.

The use of prophylactic antibiotics has been proposed.

See article at BioMed Central site:

In patients that have no symptoms of infection, management consists of close monitoring with serial blood counts, withdrawal of the offending agent (e.g., medication), and general advice on the significance of fever.

Transfusion of granulocytes would have been a solution to the problem. However, granulocytes live only ~10 hours in the circulation (for days in spleen or other tissue), which gives a very short-lasting effect. In addition, there are many complications of such a procedure.

Certain medications can alter the number and function of white blood cells.

Medications that can cause leukopenia include clozapine, an antipsychotic medication with a rare adverse effect leading to the total absence of all granulocytes (neutrophils, basophils, eosinophils). The antidepressant and smoking addiction treatment drug bupropion HCl (Wellbutrin) can also cause leukopenia with long-term use. Minocycline, a commonly prescribed antibiotic, is another drug known to cause leukopenia. There are also reports of leukopenia caused by divalproex sodium or valproic acid (Depakote), a drug used for epilepsy (seizures), mania (with bipolar disorder) and migraine.

The anticonvulsant drug, lamotrigine, has been associated with a decrease in white blood cell count.

The FDA monograph for metronidazole states that this medication can also cause leukopenia, and the prescriber information suggests a complete blood count, including differential cell count, before and after, in particular, high-dose therapy.

Immunosuppressive drugs, such as sirolimus, mycophenolate mofetil, tacrolimus, ciclosporin, leflunomide and TNF inhibitors, have leukopenia as a known complication. Interferons used to treat multiple sclerosis, such as interferon beta-1a and interferon beta-1b, can also cause leukopenia.

Chemotherapy targets cells that grow rapidly, such as tumors, but can also affect white blood cells, because they are characterized by bone marrow as rapid growing. A common side effect of cancer treatment is neutropenia, the lowering of neutrophils (a specific type of white blood cell).

Decreased white blood cell count may be present in cases of arsenic toxicity.

In developing new chemotherapeutics（化疗方法），the efficacy of the drug against the disease is often balanced against the likely level of myelotoxicity the drug will cause. In-vitro colony forming cell (CFC) assays using normal human bone marrow grown in appropriate semi-solid media such as ColonyGEL have been shown to be useful in predicting the level of clinical myelotoxicity a certain compound might cause if administered to humans. These predictive in-vitro assays reveal effects the administered compounds have on the bone marrow progenitor cells that produce the various mature cells in the blood and can be used to test the effects of single drugs or the effects of drugs administered in combination with others.

A large number of drugs

have been associated with agranulocytosis, including antiepileptics (such as carbamazepine and valproate), antithyroid drugs (carbimazole, methimazole, and propylthiouracil), antibiotics (penicillin, chloramphenicol and co-trimoxazole), ACE inhibitors (benazepril), cytotoxic drugs, gold, NSAIDs (indomethacin, naproxen, phenylbutazone, metamizole), mebendazole, allopurinol the antidepressants mianserin and mirtazapine, and some antipsychotics (the atypical antipsychotic clozapine in particular). Clozapine users in the United States, Australia, Canada, and the UK must be nationally registered for monitoring of low WBC and absolute neutrophil counts (ANC).

Although the reaction is generally idiosyncratic rather than proportional, experts recommend that patients using these drugs be told about the symptoms of agranulocytosis-related infection, such as a sore throat and a fever.

The Centers for Disease Control traced outbreaks of agranulocytosis among cocaine users, in the US and Canada between March 2008 and November 2009, to the presence of levamisole in the drug supply. The Drug Enforcement Administration reported that, as of February 2010, 71% of seized cocaine lots coming into the US contained levamisole as a cutting agent. Levamisole is an antihelminthic (i.e. deworming) drug used in animals. The reason for adding levamisole to cocaine is unknown, although it can be due to their similar melting points and solubilities.

Bone marrow suppression due to azathioprine can be treated by changing to another medication such as mycophenolate mofetil (for organ transplants) or other disease-modifying drugs in rheumatoid arthritis or Crohn's disease.

Low white cell count may be due to acute viral infections, such as a cold or influenza. It has been associated with chemotherapy, radiation therapy, myelofibrosis, aplastic anemia (failure of white cell, red cell and platelet production), stem cell transplant, bone marrow transplant, HIV, AIDS, and steroid use.

Other causes of low white blood cell count include systemic lupus erythematosus, Hodgkin's lymphoma, some types of cancer, typhoid, malaria, tuberculosis, dengue, rickettsial infections, enlargement of the spleen, folate deficiencies, psittacosis, sepsis, Sjögren's syndrome and Lyme disease. It has also been shown to be caused by deficiency in certain minerals, such as copper and zinc.

Pseudoleukopenia can develop upon the onset of infection. The leukocytes (predominately neutrophils, responding to injury first) start migrating toward the site of infection, where they can be scanned. Their migration causes bone marrow to produce more WBCs to combat infection as well as to restore the leukocytes in circulation, but as the blood sample is taken upon the onset of infection, it contains low amount of WBCs, which is why it is termed "pseudoleukopenia".

Autoimmune neutropenia is a form of neutropenia which is most common in infants and young children where the body identifies the neutrophils as enemies and makes antibody to destroy them.

Primary autoimmune neutropenia (AIN) is an autoimmune disease first reported in 1975 that primarily occurs in infancy. In autoimmune neutropenia, the immune system produces autoantibodies directed against the neutrophilic protein antigens in white blood cells known as granulocytic neutrophils (granulocytes, segmented neutrophils, segs, polysegmented neutrophils, polys). These antibodies destroy granulocytic neutrophils. Consequently, patients with autoimmune neutropenia have low levels of granulocytic neutrophilic white blood cells causing a condition of neutropenia. Neutropenia causes an increased risk of infection from organisms that the body could normally fight easily.

Who is Affected?

Primary autoimmune neutropenia has been reported as early as the second month of life although most cases are diagnosed in children between 5 and 15 months of age. Girls have a slightly higher risk of developing AIN than boys. In neutropenia discovered at birth or shortly after birth, a diagnosis of allo-immune neutropenia (from maternal white blood cell antibodies passively transferred to the infant) is more likely.

Neutropenia

In infants neutropenia is defined by absolute neutrophil counts less than 1000/uL. After the first year of life neutropenia is defined by absolute counts less than 1500/uL. Neutropenia may be primary in which it is the only blood abnormality seen. In secondary neutropenia, other primary conditions occur, including other autoimmune diseases, infections, and malignancies. Neutropenia is considered chronic when it persists for more than 6 months.

Symptoms and Disease Course

Neutropenia, which may be discovered on routine blood tests, typically causes benign infections even when the condition is severe. Ear infections (otitis media) are the most common infection seen in autoimmune neutropenia and typically infection responds to antibiotic treatment alone. Infections associated with primary AIN are usually mild and limited, including skin infections such as impetigo, gastroenteritis, upper respiratory tract infections, and ear infections. Rarely, cellulitis and abscesses may occur.

Studies of children studied for up to six years showed that most cases of autoimmune neutropenia resolved spontaneously after a median of 17 months. In 80 percent of patients, neutropenia persisted for 7 to 24 months.

Diagnosis

Patients with autoimmune neutropenia are diagnosed on the basis of blood tests showing neutropenia and the presence of granulocyte-specific antibodies. In some cases, tests for granulocyte-specific antibodies need to be repeated several times before a positive result is seen. Bone marrow aspiration, if performed, is typically normal or it can show increased cell production with a variably diminished number of segmented granulocytes.

s association with prior parvovirus B19 has been made, but this hasn’t been confirmed. Similar to the platelet deficiency idiopathic thrombocytopenic purpura, vaccines are suspected of triggering this disorder.

Treatment

Treatment consists of corticosteroids to reduce autoantibody production, antibiotics to prevent infection and granulocyte colony-stimulating factor (G-CSF) to temporarily increase neutrophil counts. In cases of severe infection or the need for surgery, intravenous immunoglobulin therapy may be used.

Neutropenic vs non-neutropenic candidemia is treated differently.

An intravenous echinocandin such as anidulafungin, caspofungin or micafungin is recommended as first-line therapy for fungemia, specifically candidemia. Oral or intravenous fluconazole is an acceptable alternative. The lipid formulation amphotericin B is a reasonable alternative if there is limited antifungal availability, antifungal resistance, or antifungal intolerance.

Monocytosis is an increase in the number of monocytes circulating in the blood. Monocytes are white blood cells that give rise to macrophages and dendritic cells in the immune system.

In humans, 950/μL is regarded as at the upper limit of normal; monocyte counts above this level are regarded as monocytosis.

Monocytosis has sometimes been called mononucleosis, but that name is usually reserved specifically for infectious mononucleosis.

There is no real treatment for Felty's syndrome, rather the best method in management of the disease is to control the underlying rheumatoid arthritis. Immunosuppressive therapy for RA often improves granulocytopenia and splenomegaly; this finding reflects the fact that Felty's syndrome is an immune-mediated disease. A major challenge in treating FS is recurring infection caused by neutropenia. Therefore, in order to decide upon and begin treatment, the cause and relationship of neutropenia with the overall condition must be well understood. Most of the traditional medications used to treat RA have been used in the treatment of Felty's syndrome. No well-conducted, randomized, controlled trials support the use of any single agent. Most reports on treatment regimens involve small numbers of patients.

Splenectomy may improve neutropenia in severe disease.

Use of rituximab and leflunomide have been proposed.

Use of gold therapy has also been described.

Prognosis is dependent on the severity of symptoms and the patient's overall health.

Monocytopenia is a form of leukopenia associated with a deficiency of monocytes. The causes of monocytopenia include: acute infections, stress, treatment with glucocorticoids, aplastic anemia, hairy cell leukemia, acute myeloid leukemia, treatment with myelotoxic drugs and genetic syndromes, as for example MonoMAC syndrome.

It has been proposed as a measure to predict neutropenia, though some research indicates that it is less effective than lymphopenia.

The most commonly known pathogen is "Candida albicans", causing roughly 70% of fungemias, followed by "Candida glabrata" with 10%, "Aspergillus" with 1% and "Saccharomyces" as the fourth most common. However, the frequency of infection by "C. glabrata", "Saccharomyces boulardii", "Candida tropicalis", "C. krusei" and "C. parapsilosis" is increasing, perhaps because significant use of fluconazole is common or due to increase in antibiotic use.

New emerging pathogen: "Candida auris" is an emerging multidrug-resistant (MDR) yeast that can cause invasive infections and is associated with high mortality. It was first described in 2009 after being isolated from external ear discharge of a patient in Japan. Since the 2009 report, C. auris infections, specifically fungemia, have been reported from South Korea, India, South Africa, and Kuwait. Although published reports are not available, C. auris has also been identified in Colombia, Venezuela, Pakistan, and the United Kingdom.

Individuals at higher risk are often prescribed prophylactic medication to prevent an infection from occurring. A patient's risk level for developing an opportunistic infection is approximated using the patient's CD4 T-cell count and sometimes other markers of susceptibility. Common prophylaxis treatments include the following:

Since opportunistic infections can cause severe disease, much emphasis is placed on measures to prevent infection. Such a strategy usually includes restoration of the immune system as soon as possible, avoiding exposures to infectious agents, and using antimicrobial medications ("prophylactic medications") directed against specific infections.

Monocytosis often occurs during chronic inflammation. Diseases that produce such a chronic inflammatory state:

- Infections: tuberculosis, brucellosis, listeriosis, subacute bacterial endocarditis, syphilis, and other viral infections and many protozoal and rickettsial infections (e.g. kala azar, malaria, Rocky Mountain spotted fever).

- Blood and immune causes: chronic neutropenia and myeloproliferative disorders.

- Autoimmune diseases and vasculitis: systemic lupus erythematosus, rheumatoid arthritis and inflammatory bowel disease.

- Malignancies: Hodgkin's disease and certain leukaemias, such as chronic myelomonocytic leukaemia (CMML) and monocytic leukemia.

- Recovery phase of neutropenia or an acute infection.

- Obesity (cf. Nagareddy et al. (2014), Cell Metabolism, Vol. 19, pp 821-835)

- Miscellaneous causes: sarcoidosis and lipid storage disease.

Inflammation can spread to other parts of the gut in patients with typhlitis. The condition can also cause the cecum to become distended and can cut off its blood supply. This and other factors can result in necrosis and perforation of the bowel, which can cause peritonitis and sepsis.

Historically, the mortality rate for typhlitis was as high as 50%, mostly because it is frequently associated with bowel perforation. More recent studies have demonstrated better outcomes with prompt medical management, generally with resolution of symptoms with neutrophil recovery without death

Systemic corticosteroids such as (prednisone) can produce rapid improvement and are the “gold standard” for treatment. The temperature, white blood cell count, and eruption improve within 72 hours. The skin lesions clear within 3 to 9 days. Abnormal laboratory values rapidly return to normal. There are, however, frequent recurrences. Corticosteroids are tapered within 2 to 6 weeks to zero.

Resolution of the eruption is occasionally followed by milia and scarring. The disease clears spontaneously in some patients. Topical and/or intralesional corticosteroids may be effective as either monotherapy or adjuvant therapy.

Oral potassium iodide or colchicine may induce rapid resolution.

Patients who have a potential systemic infection or in whom corticosteroids are contraindicated can use these agents as a first-line therapy.

In one study, indomethacin, 150 mg per day, was given for the first week, and 100 mg per day was given for 2 additional weeks. Seventeen of 18 patients had a good initial response; fever and arthralgias were markedly attenuated within 48 hours, and eruptions cleared between 7 and 14 days.

Patients whose cutaneous lesions continued to develop were successfully treated with prednisone (1 mg/kg per day). No patient had a relapse after discontinuation of indomethacin.

Other alternatives to corticosteroid treatment include dapsone, doxycycline, clofazimine, and cyclosporine. All of these drugs influence migration and other functions of neutrophils.

Typhlitis is a medical emergency and requires prompt management. Untreated typhlitis has a poor prognosis, particularly if associated with pneumatosis intestinalis (air in the bowel wall) and/or bowel perforation, and has significant morbidity unless promptly recognized and aggressively treated.

Successful treatment hinges on:

1. Early diagnosis provided by a high index of suspicion and the use of CT scanning

2. Nonoperative treatment for uncomplicated cases

3. Empiric antibiotics, particularly if the patient is neutropenic or at other risk of infection.

In rare cases of prolonged neutropenia and complications such as bowel perforation, neutrophil transfusions can be considered but have not been studied in a randomized control trial. Elective right hemicolectomy may be used to prevent recurrence but is generally not recommended

"...The authors have found nonoperative treatment highly effective in patients who do not manifest signs of peritonitis, perforation, gastrointestinal hemorrhage, or clinical deterioration. Recurrent typhlitis was frequent after conservative therapy (recurrence rate, 67 percent), however," as based on studies from the 1980s

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.

Morning pseudoneutropenia is a transient reduction in the measured neutrophil count from peripheral samples. This is noticed in some patients who are taking antipsychotic medication. Morning pseudoneutropenia is thought to be due to diurnal variation in the amount of circulating white blood cells and changes in the levels of hematopoietic cytokines and granulocyte colony stimulating factor (GCSF). Antipsychotics may amplify the natural variation in these hematopoietic factors.

Neutropenia is a hematological disorder characterized by an abnormally low number of neutrophils in the blood. Neutrophils usually make up 50-70% of circulating white blood cells and serve as the primary defense against infections. There is some variability in the neutrophil counts depending upon when the sample is taken, where the blood sample is taken from, and the system used by the medical lab for measuring the blood cells, but any significant reduction in function or number below the appropriate range may predispose individuals to infections.

Case reports of such incidences are reported with Clozapine and Risperidone and Aripiprazole.

These case reports suggest that the observed cases of the morning pseudoneutropenia did not proceed to become agranulocytosis which is a significant and dangerous side effect of some of antipsychotics. Hence it was suggested that although the morning neutrophil count may appear low, if the antipsychotic medication were considered efficaceous then white cell counts may be repeated in the afternoon prior to making a decision based only on the morning counts.