Can mutations in ELA2, neutrophil elastase expression or differential cell toxicity explain sulphasalazine-induced agranulocytosis?

BACKGROUND: Drug-induced agranulocytosis, a severe side effect marked by a deficit or absolute lack of granulocytic white blood cells, is a rare side-effect of the anti-inflammatory drug sulphasalazine. Mutations in the human neutrophil elastase gene (ELA2), causing increased intracellular concentration of this serine protease, inhibits neutrophil differentiation in severe congenital neutropenia (SCN). Since the clinical symptoms of agranulocytosis and SCN are similar, we hypothesized that it may origin from a common genetic variation in ELA2 or that sulphasalazine may affect human neutrophil elastase activity and protein expression. METHODS: We screened for genetic differences in ELA2 in DNA from 36 patients who had suffered from sulphasalazine-induced agranulocytosis, and compared them with 72 patients treated with sulphasalazine without blood reactions. We also performed in vitro studies of the blood cell lines HL60 and U937 after sulphasalazine exposure with respect to cell survival index, neutrophil elastase protein expression and activity. RESULTS: None of the mutations in ELA2, which previously have been reported to be associated with SCN, was found in this material. Protein expression of human neutrophil elastase in lymphoma U937 cells was not affected by treatment with concentrations equivalent to therapeutic doses. Cell survival of lymphoma U937 and promyelocytic leukemia HL-60 cells was not affected in this concentration range, but exhibited a decreased proliferative capacity with higher sulphasalazine concentrations. Interestingly the promyelocytic cells were more sensitive to sulphasalazine than the lymphoma cell line. CONCLUSION: Neutrophil elastase expression and ELA2 mutations do, however, not seem to be involved in the etilogy of sulphasalazine-induced agranulocytosis. Why sulphasalazine is more toxic to promyelocytes than to lymphocytes remains to be explained

Human neutrophil elastase is not a target for therapy in chronic myeloid leukaemia

No abstract available

In vitro induction of myeloid leukemia-specific CD4 and CD8 T cells by CD40 ligand-activated B cells gene modified to express primary granule proteins

The primary granule proteins (PGP) of myeloid cells are a source of multiple antigens with immunotherapeutic potential for myeloid leukemias. Therefore, we developed a method to induce T-cell responses to PGP protein sequences. We found that gene-transfected antigen-presenting cells efficiently expand functionally competent PGP-specific CD4 and CD8 T cells. The system was optimized using T-cell responses to autologous CD40-activated B cells (CD40-B) transfected with a cytomegalovirus pp65-encoding expression vector. To generate leukemia-specific T cells, expression vectors encoding the PGP proteinase 3 (PR3), human neutrophil elastase, and cathepsin-G were transfected into CD40-B cells to stimulate post-allogeneic stem cell transplantation T cells from five patients with myeloid and three with lymphoid leukemias. T-cell responses to PGP proteinase 3 and human neutrophil elastase were observed in CD8+ and CD4+ T cells only in patients with myeloid leukemias. T-cell responses against cathepsin-G occurred in both myeloid and lymphoblastic leukemias. T cells from a patient with chronic myelogenous leukemia (CML) and from a posttransplant CML patient, expanded against PGP, produced IFN-gamma or were cytotoxic to the patient's CML cells, demonstrating specific antileukemic efficacy. This study emphasizes the clinical potential of PGP for expansion and adoptive transfer of polyclonal leukemia antigen-specific T cells to treat leukemia

Cyclic neutropenia in a basset hound

A 6 month old, male basset hound was referred for intermittent malaise, and pyrexia that repeated every 10-11 days. Sequential blood counts and bone marrow aspirates demonstrated severe neutropaenia and increased myeloid precursor cells in the bone marrow from day two of each cycle. By day five the bone marrow had predominantly mature neutrophils and band cells, and by day 10 the myeloid precursors had decreased with a myeloid:erythroid of 0.4:1. During the same period the blood neutrophils had rebounded to normal counts by day five, and were declining by day 9 and 10. The monocytes and platelets were oscillating in an opposite phase to the neutrophils. The age of onset, regular cycle length, oscillation of neutrophil, platelet and monocyte counts and characteristic bone marrow cytology were diagnostic for cyclic neutropaenia. This syndrome has never before been described in any breed other than the grey collie. The grey collie gene mutation was not found in this dog. However, based on the clinical signs, and haematological and bone marrow results, it can be deduced that cyclic neutropaenia may develop as a result of other mutations in neutrophil elastase expression.http://vetrecordcasereports.bmj.comhb201