FM-SRP resulted in clinical and microbiological improvement 6 weeks post-treatment, but produced a moderate systemic acute-phase response including elevated inflammatory mediators 1 day post-treatment.

Hematopoietic function of some aplastic anemia (AA) patients is dependent on the administration of cyclosporine (CyA). To investigate whether certain HLA class II genes are associated with susceptibility to such CyA-dependent AA, we determined the HLA class II alleles of 59 AA patients treated with CyA. Among 26 patients successfully treated with CyA, 13 required a small dose of CyA to maintain stable hematopoiesis. Of these 13 AA patients, 10 shared an HLA class II haplotype of DRB1*1501-DQA1*0102-DQB1*0602. None of the 13 responders who obtained a sustained remission off CyA therapy possessed this haplotype. In the 10 patients who shared the HLA class II haplotype, single-strand conformation polymorphism analysis of each gene fragment of this haplotype failed to detect a polymorphism in the nucleotide sequence. When the AA patients were assessed for their likelihood to respond to CyA therapy, the response rate in patients with this haplotype (71%) was significantly higher than that of patients with another haplotype associated with HLA-DR2, DRB1*1502-DQA1*0103- DQB1*0601 (36%) and that of patients without HLA-DR2 (35%). These findings indicate that the CyA-dependent response of AA is closely related to an HLA class II haplotype of DRB1*1501-DQA1*0102-DQB1*0602 and suggest that, in AA patients with this haplotype, immune mechanisms play an important role in the pathogenesis of bone marrow failure.

Anthracyclines are effective antineoplastic drugs, but they frequently cause dose-related cardiotoxicity. The cardiotoxicity of conventional anthracycline therapy highlights a need to search for methods that are highly sensitive and capable of predicting cardiac dysfunction. We measured the plasma level of brain natriuretic peptide (BNP) to determine whether BNP might serve as a simple diagnostic indicator of anthracycline-induced cardiotoxicity in patients with acute leukemia treated with a daunorubicin (DNR)-containing regimen. Thirteen patients with acute leukemia were treated with a DNR-containing regimen. Cardiac functions were evaluated with radionuclide angiography before chemotherapies. The plasma levels of atrial natriuretic peptide (ANP) and BNP were measured at the time of radionuclide angiography. Three patients developed congestive heart failure after the completion of chemotherapy. Five patients were diagnosed as having subclinical heart failure after the completion of chemotherapy. The plasma levels of BNP in all the patients with clinical and subclinical heart failure increased above the normal limit (40 pg/ml) before the detection of clinical or subclinical heart failure by radionuclide angiography. On the other hand, BNP did not increase in the patients without heart failure given DNR, even at more than 700 mg/m². The plasma level of ANP did not always increase in all the patients with clinical and subclinical heart failure. These preliminary results suggest that BNP may be useful as an early and sensitive indicator of anthracycline-induced cardiotoxicity.

The existence of T cells capable of inhibiting in vitro hematopoiesis has been shown in aplastic anemia (AA), although whether such inhibition is mediated by a specific immune reaction involving an HLA allele remained unknown. We isolated a CD4+ Vβ21+ T-cell clone that was most dominant among Vβ21+ T cells in the bone marrow (BM) of an AA patient whose HLA-DRB1 alleles included 1501 and 0405. The T-cell clone named NT4.2 lysed an autologous Epstein-Barr virus-transformed lymphoblastoid cell line (LCL) and phytohemagglutinin-stimulated lymphocytes (PHA-blasts) as well as allogeneic LCLs sharing HLA-DRB1*0405. Cytotoxicity against LCL cells and PHA-blasts by NT4.2 was blocked by anti–HLA-DR monoclonal antibody (MoAb) or anti-CD3 MoAb. NT4.2 also lysed autologous BM mononuclear cells enriched with CD34+ cells that had been cultured for one week in the presence of colony-stimulating factors as well as allogeneic CD34+ cells of a normal individual carrying HLA-DRB1*0405, cultured in the same way. Moreover, NT4.2 strongly inhibited colony formation by hematopoietic progenitor cells derived from cultured CD34+ cells sharing HLA-DRB1*0405. These results indicate that the AA patient has T cells capable of killing hematopoietic cells in an HLA-DRB1*0405-restricted manner and that such cytotoxic T cells may contribute to the pathogenesis of AA.