The laboratory data of the disease control were different from the other controls as he had undergone treatment with IVIG and aspirin. All blood samples were confirmed as blood group A, RhD positive. The laboratory findings HIF cancer during the disease course of case A are shown in Table 2. At day 30, ANC values were significantly decreased and platelet counts had contrastingly increased. The presence of autoantibodies to neutrophils was tested by D-GIFT and I-GIFT. D-GIFT was negative

in all subjects. Fig. 3B shows a representative I-GIFT result using the leukocytes of case C and the serum of case A. The M2 gate shows the levels of the neutrophil-associated antibody attaining an arbitrary level of fluorescence. No antibodies were present on day 5, before IVIG treatment. There was a direct correlation between increase in neutrophil-associated antibody levels and neutrophil counts of case A: as the amount of antibody increased, neutrophil counts of case A were further decreased, followed by an agranulocytic stage (serum on day 13 and day 30); then, as the amount of antibody gradually decreased, neutrophil

counts of case A increased, resulting in recovery from neutropenia (serum on day 64). Similar results were observed using different neutrophils (present case, control patient and other normal volunteers) with serum from the present case (case A). The percentage of cells within the M2 gate is LY2606368 chemical structure shown in Fig. 3C, which represents the changes in the relative antibody level and the ANC of the case A. The neutrophil counts of case A inversely correlated with the level of autoantibody Cyclin-dependent kinase 3 during the patient’s clinical course. No positive results using I-GIFT were observed among the serum from the disease or normal healthy controls. Examination of the same lots of immunoglobulin used for IVIG treatment also revealed an absence of antibodies to neutrophils. Neutropenia associated with KS patients is reported to be complicated with various autoimmune disorders [6]. In this study, an autoantibody to a novel antigen on immature myeloid cells or neutrophils

was produced in a patient with KS and revealed as the possible cause of severe neutropenia. In primary autoimmune neutropenia, the autoantibody specificity has been defined and the usually recognized human neutrophil antigens (HNAs) are located on glycosylated isoforms of FcγRIIIb (CD16b) [14, 15]. Autoantibody specificity associated with secondary autoimmune neutropenia is often unknown [16] but was recently shown to be associated with pan FcRγIIIb antibodies [17]. In this case, the recognized major HNAs were negative. We tried to evaluate the specificity of the immunoglobulin binding using an immunoblot technique with cell lysates to identity the target antigens. However, we could not identify the specific protein.