The autosomal dominant macrothrombocytopenia with leukocyte inclusions, May-Hegglin anomaly (MHA), Sebastian syndrome (SBS), and Fechtner syndrome (FTNS), are rare platelet disorders characterized by a triad of giant platelets, thrombocytopenia, and characteristic Döhle body-like leukocyte inclusions. The locus for these disorders was previously mapped on chromosome 22q12.3-q13.2 and the disease gene was recently identified as MYH9, the gene encoding the nonmuscle myosin heavy chain-A. To elucidate the spectrum of MYH9 mutations responsible for the disorders and to investigate genotypephenotype correlation, we examined MYH9 mutations in an additional 11 families and 3 sporadic patients with the disorders from Japan, Korea, and China. All 14 patients had heterozygous MYH9 mutations, including three known mutations and six novel mutations (three missense and three deletion mutations). Two cases had Alport manifestations including deafness, nephritis, and cataracts and had R1165C and E1841K mutations, respectively. However, taken together with three previous reports, including ours, the data do not show clear phenotype-genotype relationships. Thus, MHA, SBS, and FTNS appear to represent a class of allelic disorders with variable phenotypic diversity.

Significantly more maternal chimeric CD8+ T cells in the livers of patients with biliary atresia suggest that maternal immunologic insults represent the underlying pathogenesis in biliary atresia. The findings support the recently postulated mechanisms of alloautoimmune and/or autoalloimmune responses.

The expression of membrane-bound Fas ligand (FasL) and Fas in lymphocytes and monocytes and levels of soluble forms of FasL (sFasL) and Fas (sFas) in plasma from human immunodeficiency virus (HIV) -positive and -negative subjects was evaluated. Surface FasL was detectable on monocytes, but poorly so on lymphocytes, even in the presence of KB8301, a metalloproteinase inhibitor. Unexpectedly, monocytes of HIV-positive subjects expressed less FasL than those of HIV-negative volunteers. sFasL levels in plasma of HIV-positive persons were elevated and correlated with levels in plasma and with HIV RNA burden. sFas levels in plasma of HIV-positive subjects were also elevated and correlated with Fas expression in apoptotic lymphocytes. Finally, culture-induced lymphocyte apoptosis of HIV-positive subjects was enhanced by anti-Fas agonistic antibody but was not inhibited by anti-FasL blocking antibodies. These results suggest that significant dysregulation of both Fas and FasL occurs in HIV infection and contributes to increased sensitivity of lymphocytes to apoptosis.

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We have recently found that intra-bone marrow-bone marrow transplantation (IBM-BMT) can be used to prevent graft-versus-host disease (GvHD), even when intensive donor lymphocyte infusion (DLI) is carried out. In the present study, in conjunction with IBM-BMT, allogeneic splenic T cells as DLI were also injected into the bone marrow cavity of lethally irradiated (8.5 Gy) recipients. The extent of GvHD was compared with that of recipients that had received allogeneic IBM-BMT plus i.v. injection of allogeneic T cells (intravenous DLI [IV-DLI]). GvHD in recipients treated with allogeneic IBM-BMT plus IBM-DLI was far milder than in those treated with allogeneic IBM-BMT plus IV-DLI. This was confirmed macroscopically and histopathologically. The frequency of regulatory T cells (Tregs) detected as CD4؉ CD25 ؉ and CD4 ؉ Foxp3 ؉ cells was significantly higher in recipients treated with IBM-BMT plus IBM-DLI than in those treated with IBM-BMT plus IV-DLI. Donor-derived helper T (Th) cells polarized to Th2 type in recipients treated with IBM-BMT plus IBM-DLI, whereas Th1 cells were dominant in recipients treated with IBM-BMT plus IV-DLI. Furthermore, the production of transforming growth factor-␤ and hepatocyte growth factor from bone marrow stromal cells was enhanced after IBM-DLI. Thus, IBM-BMT plus IBM-DLI seem to preferentially induce Tregs and Th2, resulting in the prevention of GvHD.