Successful treatment of chronic autoimmune neutropenia with cyclosporin A

Chronic primary autoimmune neutropenia (AIN) is a distinct clinical entity seen mostly in young children, characterized by persistent neutropenia with circulating anti-neutrophil antibodies and no associated disorders known to produce AIN. Herein we report a 22-year-old male who spontaneously developed severe chronic neutropenia with recurrent episodes of high fever and oral aphthous ulcers. Laboratory evaluations detected the presence of anti-granulocyte autoantibodies directed against the NA1 neutrophil-specific antigen. Clinical, laboratory and roentgenographic testing did not reveal any disorder known to be associated with AIN. The patient' s severe neutropenia did not respond to therapy with prednisone alone, but resolved following treatment with prednisone and high-dose cyclosporin A.     

The use of rh-G-CSF in chronic autoimmune neutropenia: reversal of autoimmune phenomena, a case history

An 8-year-old boy had been suffering from chronic autoimmune neutropenia for more than 5 years. The neutropenia proved to be resistant to high-dose steroids and intravenous (either low- or high-dose) immunoglobulin (Ig) therapy. The chronic autoimmune thrombocytopenia and recurrent phases of autoimmune haemolytic anaemia did, however, respond to high-dose prednisone. Other signs of immune dysregulation in this patient consisted of insulin-dependent diabetes mellitus type I (IDDM) and an acquired hypogammaglobulinaemia, most compatible with common variable immunodeficiency (CVI). Prior to rhG-CSF therapy the child had suffered for more than 2 years from recurrent life-threatening bacterial infections.
Anti-neutrophil autoantibodies had pan-FcγRIII (CD16, NA1/NA2) specificity. The neutropenia as well as the anti-neutrophil autoantibodies disappeared when subcutaneous rhG-CSF therapy was started. Upon tapering rhG-CSF, anti-FcγRIII antibodies reappeared together with an absolute neutropenia. Renewed administration resulted again in the normalization of symptoms.
Soluble FcγRIII (sFcγRIII) antigen levels in plasma increased dramatically during rhG-CSF treatment. These high levels of sFcγRIII together with increased numbers as well as decreased apoptotic reactions of neutrophils apparently result in adsorption of the autoantibodies in vivo , contributing to the normalization of autoimmune-mediated neutropenia upon rhG-CSF treatment. Long-term administration of rhG-CSF represents an alternative in the treatment of autoimmune neutropenia.     

Characterization of the bone marrow immunofluorescence test in childhood autoimmune neutropenia

The bone marrow immunofluorescenece test (BMIFT) demonstrates autoantibodies to granulocytes and their precursors on fresh-frozen bone marrow slides. It may be used to differentiate childhood autoimmune neutropenia (AIN) from other causes of childhood neutropenia, even when circulating neutrophil counts are low. We sought to characterize the diagnostic utility of the BMIFT in childhood AIN. All BMIFT requests for investigation of children with neutropenia between January 1998 and May 2007 were reviewed. Patients were classified as AIN or nonautoimmune causes. Baseline demographic data, results of BMIFT, granulocyte immunofluorescence testing and bone marrow findings were collected from clinical records and the institutional laboratory database. Seventy-six children had BMIFT performed for investigation of neutropenia. There were 45 patients diagnosed with AIN, 28 with nonimmune neutropenia and three failed tests. The median age of children with AIN was 1.2 years (range 0.3-15.3), compared with 3.6 years (range 0.1-15.7) in the nonautoimmune group. The median neutrophil count in AIN was 0.3 x 10(9)/l (0.9 x 10(9)/l in nonautoimmune). BMIFT was positive in 24 of 45 patients with AIN and 0 of 28 with nonautoimmune neutropenia (sensitivity 53%, specificity 100%, positive predictive value (PPV) 100%, negative predictive value 57%). Ten patients had other autoimmune diatheses at diagnosis. The BMIFT is a simple, highly specific test with excellent PPV and thus is a clinically useful test to confirm AIN in children.     

Neutrophil antibody specificity in different types of childhood autoimmune neutropenia.

Autoimmune neutropenia (AIN) in children can be divided into 2 forms. In primary AIN, neutropenia is the sole abnormality, and although neutrophil counts are generally below 500 microL(-1), mild bacterial infections occur. Primary AIN is mostly seen in young children and shows a self-limited course. AIN occurring in association with autoimmune diseases (secondary AIN) often shows more severe infectious complications. We analyzed clinical and serological data from 28 pediatric patients with AIN to evaluate whether there is a possible relationship between specificity of the neutrophil autoantibodies and the clinical course of the disease. Specificity of the circulating antibodies was determined with the indirect granulocyte immunofluorescence test (GIFT) and a panel of phenotyped donor neutrophils. The samples were further analyzed in the monoclonal antibody immobilization of granulocyte antigens assay (MAIGA) for neutrophil antigen (NA)1, NA2, CD11a, and CD11b specificity. With the indirect GIFT, an antibody specificity was deduced in 26 of the 28 analyzed samples. In all but 3 sera from patients with primary AIN, NA1-(76%) or NA2-(10%) specific antibodies were detected with the indirect GIFT. In 2 samples, the reactivity in the indirect GIFT was too weak to draw conclusions, but the MAIGA showed NA1 and/or NA2 specificity of the antibodies. One serum, from a patient with primary AIN with a persistent neutropenia for more than 6 years, contained NA1, possibly pan-FcgammaRIIIb, and CD11a antibodies. In 4 sera from patients with primary AIN, weak antibodies with CD11a or CD11b specificity were detected with the MAIGA. Sera from 7 patients with secondary AIN contained in all cases antibodies with pan-FcgammaRIIIb specificity, as deduced from the indirect GIFT results and absorbance/elution experiments performed with 2 sera. The MAIGA confirmed this for only 1 of the 5 tested sera. Furthermore, CD11a antibodies were detected in 1 of the 5 tested sera. In conclusion, our results indicate that primary AIN is usually associated with NA-specific antibodies, whereas secondary AIN seems to be associated with pan-FcgammaRIIIb antibodies. Thus, characterization of the antibodies in sera from children with AIN discriminates patients with primary AIN from those with secondary AIN.     

Successful treatment with G-CSF and corticosteroid of adult idiopathic autoimmune neutropenia presenting as recurrent enterocolitis

A 63-year-old woman had previously been admitted to another hospital due to fever, abdominal pain and diarrhea. She was treated with fasting, antibiotics and G-CSF administration because of the coexistence of neutropenia, and the symptoms improved. However, discontinuation of G-CSF administration resulted in a recurrence of the neutropenia accompanied with enterocolitis. After admission to our hospital, a diagnosis for idiopathic AIN was performed as she tested positive in both granulocyte immunofluorescence and granulocyte agglutination tests. Administration of corticosteroid following G-CSF resulted in a continuous increase in the neutrophil count and the disappearance of anti-neutrophil autoantibodies.     

Primary autoimmune neutropenia in children: a study of neutrophil antibodies and clinical course

BACKGROUND AND OBJECTIVES: Primary autoimmune neutropenia (AIN) in children is characterized by severe neutropenia, but mild bacterial infections and a spontaneous resolution. Neutrophil autoantibodies are involved in the disease. The precise relationship between the specificity and level of reactivity of the antibodies with the absolute neutrophil count and frequency of infections is not known. To obtain a better insight into this relationship, we performed a follow-up study in 15 patients with primary AIN. In addition, we performed two different neutrophil antibody tests to evaluate their sensitivity and specificity. MATERIALS AND METHODS: Blood samples from 15 children were tested for neutrophil antibodies, at different time-points during the disease, by using the indirect granulocyte immunofluorescence test (GIFT) and the monoclonal antibody-specific immobilization of granulocyte antigens (MAIGA) assay. Clinical data related to the occurrence of bacterial infections and treatment, and neutrophil counts were collected. RESULTS: Early in the disease, antibodies with pan-FcRIIIb specificity were detected, and HNA-1a or HNA-1b specificity of the antibodies developed over time. The sensitivity and specificity of neutrophil antibody detection tests were higher in the GIFT than in the MAIGA assay. Variables predicting time of recovery from neutropenia were not found. Prophylactic antibiotics led to the almost complete disappearance of infections. CONCLUSIONS: In patients with primary neutropenia, neutrophil antibody specificity changes over time. Prophylactic antibiotics do benefit the patients.     

Another Example of Isoimmune Neonatal Neutropenia Due to Anti-Na1

Abstract. A review of the present knowledge of transplacental transmission of anti-neutrophil antibodies is given. A family in which one, possibly two of the three children had severe neutropenia after birth with subsequent infections, is described. An agglutinating antibody, directed against the neutrophil-specific antigen NA 1, was demonstrated in the maternal serum. The father and all three children were NA 1-positive. This case is another example of isoimmune neonatal neutropenia due to anti-NA 1 antibodies.     

Neonatal lupus manifests as isolated neutropenia and mildly abnormal liver functions

Neonatal lupus is characterized by typical clinical features and the presence of maternal autoantibodies. Mothers can have systemic lupus erythematosus (SLE) or Sj?gren's syndrome, but are commonly not affected with any clinical disease. The major clinical manifestations in the infants are cardiac, dermatological and hepatic with rare instances of hemolytic anemia, thrombocytopenia or neutropenia. We describe an infant born to a mother with anti-Ro and anti-La, who had neutropenia and mildly abnormal liver functions without other major clinical features of neonatal lupus such as cardiac or dermatological manifestations. Neutropenia improved as maternal antibody was metabolized. Antibodies from both the infant and mother bound intact neutrophils, and this binding was inhibited by 60 kDa Ro. These data imply neutropenia may be an isolated manifestation of neonatal lupus. We studied the anti-Ro antibodies of 2 other mothers who gave birth to infants with complete congenital heart block and neutropenia. Their sera also bound neutrophils. Because healthy infants do not commonly undergo complete blood counts, the incidence of neutropenia among infants of anti-Ro-positive mothers may be much higher than previously recognized. Furthermore, although other factors may contribute, these data suggest that anti-60 kDa Ro is directly involved in the pathogenesis of neutropenia.     

Lack of clinical efficacy of rituximab in the treatment of autoimmune neutropenia and pure red cell aplasia: implications for their pathophysiology

We describe 11 patients with severe refractory autoimmune cytopenias treated with the anti-CD20 monoclonal antibody rituximab. Six patients had autoimmune neutropenia (AIN), two had pure red cell aplasia (PRCA), one had AIN and autoimmune haemolytic anaemia, one had AIN and immune thrombocytopaenia purpura (ITP) and one had PRCA and ITP. Rituximab was administered at a dose of 375 mg/m² as an intravenous infusion weekly for 4 weeks. Six of eight patients with AIN and all three patients with PRCA did not respond. Two patients died: one with resistant AIN and autoimmune haemolytic anaemia died of pneumocytis pneumonia infection, and one with PRCA and ITP died of an acute exacerbation of bronchiectasis. Rituximab in AIN and PRCA appears to be less effective than Campath-1H when compared to historical data from our group. This supports the hypothesis that T cells may be important in the pathophysiology of AIN and PRCA.     

Antibodies to actin in autoimmune neutropenia

In an effort to characterize the cellular antigens recognized by anti-neutrophil antibodies in autoimmune neutropenia, we studied sera, purified immunoglobulin G (IgG) and isolated F(ab')2 from 70 neutropenic patients suspected of this diagnosis. Anti-neutrophil antibodies were found in the sera of 36 of these patients by either 125I-staph A binding or immunofluorescence cytometric techniques that detected increased binding of patients' IgG to normal neutrophils. Anti-neutrophil antibody positive sera were then evaluated for specific binding to electrophoretically separated neutrophil membrane-associated proteins by immunoblotting. A 43-Kd protein was consistently identified by eight anti-neutrophil antibody positive sera. The specificity of binding to this protein was confirmed with affinity purified IgG and F(ab')2 fragments prepared from these sera. Sera from 20 healthy normal controls and from 22 non-neutropenic, anti-neutrophil antibody negative rheumatoid arthritis patients failed to bind this protein. Separate studies identified the 43-Kd protein as actin. Purified Acanthamoeba actin comigrated with the protein and was specifically bound by anti-neutrophil antibody positive IgG. Moreover, two actin-specific monoclonal antibodies bound to the 43-Kd membrane-associated protein in immunoblots. In addition, a rabbit anti-actin antiserum not only bound to this same 43-Kd protein but also expressed anti-neutrophil antibody activity against normal human neutrophils, as did purified human anti-actin IgG prepared by affinity chromatography from the serum of one of the index patients. These studies indicate that the anti-neutrophil antibodies of certain patients with autoimmune neutropenia include autoantibodies specific for actin. The molecules on the surface of neutrophils, which have actin-like antigenic epitopes and are recognized by these anti-actin antibodies, remain to be characterized.     

Identification of autoantibodies specific for the neutrophil adhesion glycoproteins CD11b/CD18 in patients with autoimmune neutropenia.

Anti-neutrophil antibodies have been described in a variety of clinical conditions associated with neutropenia. However, relatively little is known about the antigenic specificities of naturally occurring anti-neutrophil autoantibodies. We investigated the possibility that anti-neutrophil antibodies specific for the neutrophil adhesion glycoprotein (GP) complex CD11b/CD18 might be present in the sera of some patients with autoimmune neutropenia. These membrane GPs have been shown to be highly immunogenic in the production of murine monoclonal antibodies against neutrophil antigens. Moreover, autoantibodies to the platelet membrane GP complex IIb/IIIa, another member of the integrin family of cell adhesion proteins, have been demonstrated in immune thrombocytopenic purpura. Sera from 50 patients known to have anti-neutrophil IgG antibodies were evaluated using an immunobead "antigen capture" assay, modeled after a method used to identify anti-platelet GPIIb/IIIa autoantibodies. This assay detected anti-CD11b/CD18 autoantibodies in seven of the 50 sera. Each of these seven sera demonstrated decreased IgG binding to the neutrophils of a patient with congenital deficiency of CD11b/CD18. The patient with the highest levels of anti-CD11b/CD18 suffered recurrent skin infections and cellulitis, and died of respiratory failure during one of multiple episodes of pneumonia. Purified IgGs from five of these patients demonstrated effects on adhesion and/or opsonin receptor-mediated functions when tested with intact neutrophils in vitro. Our findings indicate that some patients with autoimmune neutropenia have autoantibodies specific for the functionally important neutrophil adhesion proteins CD11b/CD18. Our findings also raise the possibility that these autoantibodies may, in some cases, interfere with neutrophil function, thereby amplifying the risk of infection associated with neutropenia.     

Serum G-CSF levels are not increased in patients with antibody-induced neutropenia unless they are suffering from infectious diseases

By the use of a G-CSF-specific ELISA we determined the serum granulocyte-colony stimulating factor (G-CSF) levels in 63 patients with antibody-induced neutropenia including neonatal immune neutropenia, autoimmune neutropenia, and drug-induced immune neutropenia. In the sera of 20 patients, elevated G-CSF levels of 60-1006 pg/ml (normal <39 pg/ml) were observed. These patients suffered from infectious diseases at the time of blood collection. G-CSF levels normalized after successful antibiotic treatment, indicating that increased G-CSF production in patients with immune neutropenia may be primarily the result of infection and not of neutropenia.     

Autoimmune neutropenia: clinical and laboratory studies in 143 patients

Summary Clinical and laboratory data of 143 patients with primary or secondary autoimmune neutropenia (AIN) were evaluated. Primary AIN was found predominantly in children below 3 years, whereas secondary AIN was more frequent in patients 40–60 years of age. Female patients with primary AIN were slightly more prevalent (54%) than male patients (46%). The peripheral blood count showed normal or diminished leukocyte counts with median absolute neutrophil counts of 250 cells/l. In 38% of the patients neutropenia was accompanied by monocytosis. Bone marrow examination revealed in 95% a normo- or hypercellular marrow with a marked reduction of mature neutrophils in 56% of the specimens. Twenty-three percent of the sera showed specificity for the NA1 antigen. Patients were usually affected by benign bacterial infections of the skin and of the upper respiratory tract, as well as by recurrent otitis media. Infections were treated symptomatically, and only six patients required continuous administration of antibiotics. Remission of neutropenia during treatment occurred in three of six patients treated with intravenous immunoglobulin G and in three of four patients who received steroid therapy. Except for one patient neutropenia relapsed after discontinuation of therapy. During a follow-up of 6–36 months, spontaneous remission has been observed in four patients.This work was supported by theDeutsche Forschungsgemeinschaft (Mu 277/9-7)     

Congenital neutropenia

Congenital neutropenia is strictly defined as neutropenia present at birth. However, it is more generally used to describe neutropenia secondary to inherited genetic mutations. This review will discuss the presentation of such children and the various causes of congenital neutropenia. In particular, it will focus on severe congenital neutropenia (SCN) and the recent discovery of mutations in the gene encoding neutrophil elastase in the majority of cases of SCN. The potential mechanisms of pathogenesis and of transformation to leukaemia will be discussed. Shwachman-Diamond Syndrome and other less common causes of congenital neutropenia will also be reviewed. Finally, an approach to the child with potential congenital neutropenia will be presented.     

Autoimmune neutropenia due to antineutrophil antibodies in a patient with primary sclerosing cholangitis

Autoimmune neutropenia (AIN) is defined as a decrease in the circulating absolute neutrophil count (ANC) to less than 1500/μl caused by serum antineutrophil antibodies. Secondary AIN is associated with various autoimmune diseases. Herein we present the case of a patient with primary sclerosing cholangitis (PSC) who developed secondary AIN. A 19-year-old man was admitted due to liver injury, and a diagnosis of PSC was established by cholangiogram and liver biopsy. Severe neutropenia, with the ANC down to 130/μl, developed during his hospital course. No medications had been given at that time and bone marrow aspiration revealed no abnormality. Therefore we suspected secondary AIN as a causative etiology and examined whether antineutrophil antibodies were detectable in the patient’s sera by flow cytometric analysis of the granulocyte indirect immunofluorescence test. We found that antineutrophil antibody was strongly positive on admission, and the titer decreased along with recovery from neutropenia. This is the first reported case of a patient with PSC who developed AIN, with detection of serum antineutrophil antibodies.     

Successful treatment of autoimmune neutropenia with recombinant human granulocyte-colony stimulating factor (R-metHuG-CSF)

Autoimmune neutropenia (AIN) is characterized by antibody mediated peripheral destruction of neutrophils. Since there is no effective treatment, antibiotics have to be used frequently for recurrent infections. Five selected patients with serologically proven AIN were treated with r-metHuG-CSF at 5–8 μg/kg body weight (300–480 μg) daily; the dose and frequency of r-metHuG-CSF was reduced after neutrophil counts above 1.0×10⁹/l were obtained. R-metHuG-CSF is effective in AIN and causes a sustained rise in ANC which can be maintained on a low dose administered twice or thrice weekly.     

Investigating severe neutropenia with a simple bone marrow immunofluorescence test

Severely neutropenic patients who are suspected of having circulating autoantibodies to neutrophils and/or myeloid precursors present a diagnostic problem. This report describes the use of a simple bone marrow immunofluorescence test (BMIFT) to demonstrate autoantibodies reactive with the patient's own bands, neutrophils and myeloid precursors represented on fresh-frozen bone marrow aspirate smears. Positive results were seen in two of 13 evaluable marrows from children with primary neutropenia and in eight of 44 evaluable marrows from adults with primary or secondary neutropenia. The BMIFT is simple enough to perform in most laboratory environments and provides serological information to support a diagnosis of immune neutropenia when other means of investigation are precluded.     

The successful treatment of G-CSF in autoimmune neutropenia with liver cirrhosis complicated by esophageal varices]

A 72 year-old woman was admitted to our hospital for hematoemesis. After admission, endoscopic examination showed esophageal varices with a red color sign which indicated endoscopic injection sclerotherapy (EIS). Concurrently, however, laboratory findings revealed severe neutropenia in peripheral blood, while bone marrow examination showed marked reduction of mature granulocytes with mild myeloid hyperplasia. As a result of those hematological abnormalities, EIS was halted. Concerning the pathogenesis of this neutropenia, immunofluorescence technique using flow cytometry disclosed the presence of anti-neutrophil autoantibody in the serum, giving a clinical diagnosis of autoimmune neutropenia (AIN). Thereafter, a conventional regimen of corticosteroids as an initial therapy and steroid pulse therapy as a succeeding maneuver were instituted, but in vain. As a last resort, 125 micrograms/body of rhG-CSF was given daily subcutaneously. As a consequence, significant increase in granulocyte count, though transient, was attained, which made EIS possible without any episodes of infections. It seems most likely that a high dose of rhG-CSF exerts beneficial effects as a prophylactic and therapeutic regimen against infections in patients with AIN.     

Alloimmune neonatal neutropenia due to an antibody to the neutrophil Fc-gamma receptor III with maternal deficiency of CD16 antigen.

Antibodies to the neutrophil-specific antigens NA1 and NA2 are associated with alloimmune neonatal neutropenia (ANN), autoimmune neutropenia of childhood, and acute pulmonary transfusion reactions. These antigens have been found to be located on the neutrophil Fc-gamma receptor III (FcRIII). The mother of a child with ANN was found to lack both NA antigens and to produce an antibody that reacted with all normal neutrophils tested. We used maternal antibody and a CD16 monoclonal antibody (MoAb) that has specificity for FcRIII to immunoblot and immunoprecipitate neutrophil membranes of various NA phenotypes. Both antibodies immunoblotted an approximately 40- to 70-Kd glycoprotein (GP) on NA1, NA2-positive membrane, an approximately 40- to 55-Kd GP on NA1-homozygous membranes, and an approximately 55- to 70-Kd GP on NA2-homozygous membranes. Both antibodies also immunoprecipitated a 50- to 80-Kd GP from NA1, NA2-positive cells, a 50- to 60-Kd GP from NA1-homozygous cells, and a 55- to 80-Kd GP from NA2-homozygous cells. To further examine the specificity of the maternal antibody, sequential immunoprecipitation studies were performed using maternal antisera and a CD16 MoAb. After extracts of 125I surface-labeled neutrophils were precleared with maternal serum, CD16 MoAbs no longer immunoprecipitated any GP. Neither the CD16 MoAb nor a rabbit polyclonal antibody specific for FcRIII detected any GP in maternal neutrophil membranes by immunoblotting. Neutrophil FcRIII is a glycosyl-phosphatidylinositol anchored membrane GP as is decay accelerating factor and both are absent from neutrophils of patients with paroxysmal nocturnal hemoglobinuria (PNH). Maternal neutrophil membranes were probed with antibody specific for DAF and an 80-Kd GP was detected. This woman also has had no clinical evidence of PNH. These studies provide further evidence that the NA1 and NA2 antigens are on FcRIII and identify a healthy person whose neutrophils lack not only the neutrophil specific antigens NA1 and NA2 but multiple other epitopes of FcRIII and, therefore, likely lack FcRIII entirely.     

Severe chronic neutropenia: treatment and follow-up of patients in the Severe Chronic Neutropenia International Registry

Severe chronic neutropenia (SCN) is defined as an absolute neutrophil (ANC) of less than 0.5 x 10(9)/L, lasting for months or years. Congenital, cyclic, and idiopathic neutropenia are principal categories of SCN. Since 1994, the Severe Chronic Neutropenia International Registry (SCNIR) has collected data to monitor the clinical course, treatments, and disease outcomes for SCN patients. This report summarizes data for 853 patients, almost all treated with daily or alternate-day recombinant human granulocyte colony-stimulating factor (G-CSF or Filgrastim). G-CSF treatment increased the ANC overall from 0.34 x 10(9)/L +/- 0.018 pre-treatment to 3.70 x 10(9)/L +/- 0.18 during the first year of treatment. For most patients, the responses were durable with patients remaining on the same dose of G-CSF for many years. Long-term hematological observations showed stable mean leukocyte and neutrophil counts and gradually increasing hemoglobin levels. Thrombocytopenia developed in 4% of patients. As of January 1, 2000, myelodysplasia (MDS) or acute myelogenous leukemia (AML) has occurred in 35 of 387 patients with congenital neutropenia with a cumulative risk of 13% after 8 years of G-CSF treatment. This event occurred without a predictable relationship to the duration or dose of G-CSF treatment. No patients with cyclic or idiopathic neutropenia developed MDS or AML. Other important adverse events included hepatomegaly, osteoporosis, vasculitis, glomerulonephritis, and deaths in 4 of 14 cases requiring splenectomy. Growth and development and the outcome of pregnancy appeared to be unaffected by G-CSF treatment. These data indicate that congenital, cyclic, and idiopathic neutropenia can be effectively treated with long-term G-CSF. The risk of leukemia, osteoporosis, other potentially adverse events, and pregnancy outcome need to be further evaluated with continuing long-term observations.