Atsushi Komatsuda

A clinical analysis of 52 adult patients with hemophagocytic syndrome: the prognostic significance of the underlying diseases.

We retrospectively analyzed 52 adult patients with hemophagocytic syndrome (HPS). The underlying diseases were heterogeneous, including malignant lymphoma (lymphoma-associated hemophagocytic syndrome [LAHS]) in 26 patients, systemic lupus erythematosus in 3 patients, viral infections in 7 patients, and bacterial or fungal infections in 6 patients. More than 83% of patients received prednisolone as an initial treatment. Multiple-agent chemotherapies (cyclophosphamide, doxoru-bicin, and vincristine) were administered to 96% of LAHS patients after a histopathological diagnosis of lymphoma. HPSs were controllable and remissions were achieved except for those patients with LAHS, fulminant Epstein-Barr virus-ssociated HPS, and an immunosuppressive state. Twenty-one (81%) of the LAHS patients had uncontrollable HPS and died of multiple organ failure and disseminated intravascular coagulation.The median survival time of LAHS patients was 83 days. In contrast, 3 (12%) of the other HPS patients died of multiple organ failure within 44 days.The clinical manifestations and the laboratory findings of LAHS and the other HPSs were too variable to establish the prognosis based only on the findings at the onset of HPS. The prognostic factors of adult HPS were found to be the underlying diseases, notably malignant lymphoma and infections, accompanied by the immunosuppressive state.

Up‐regulated expression of Toll‐like receptors mRNAs in peripheral blood mononuclear cells from patients with systemic lupus erythematosus

Recent studies in animal models for systemic lupus erythematosus (SLE) have shown that Toll‐like receptors (TLR‐7 and TLR‐9) and interferon (IFN)‐α are involved in the pathogenesis of murine lupus. Recent studies using flow cytometry have also shown increased expression of TLR‐9 in peripheral blood mononuclear cells (PBMCs) from SLE patients. In this study, we performed quantitative real‐time reverse transcription–polymerase chain reaction analyses of PBMCs from 21 SLE patients and 21 healthy subjects, to estimate TLR2, TLR3, TLR4, TLR5, TLR7, TLR8, TLR9, IFN‐α and LY6E (a type I IFN‐inducible gene) mRNA expression levels. Expression levels of TLR2, TLR7, TLR9, IFN‐α and LY6E mRNAs in SLE patients were significantly higher than those in healthy controls. Expression levels of TLR7 and TLR9 mRNAs correlated with that of IFN‐α mRNA in SLE patients. These results suggest that up‐regulated expression of TLR7 and TLR9 mRNAs together with increased expression of IFN‐α mRNA in PBMCs may also contribute to the pathogenesis of human lupus.

Circulating antibodies against α‐enolase in patients with primary membranous nephropathy (MN)

MN is characterized by the glomerular deposition of IgG4 immune complexes. This suggests that nephritogenic immune responses in MN are of the Th2 T helper cell type; however, the pathogenesis of MN is still unknown. In this study we examined sera from patients with primary MN for antibodies to renal proteins. A 47‐kD protein in both human and porcine renal extracts was found by immunoblotting to react specifically with serum IgG from some patients. This protein was purified from porcine kidney and identified as α‐enolase on the basis of its partial amino acid sequences. Sera from 87 patients with primary MN, 24 patients with secondary MN (15 rheumatoid arthritis patients, nine systemic lupus erythematosus patients), and 16 healthy subjects were examined by ELISA using purified α‐enolase. In 60 (69%) patients with primary MN and 14 (58%) patients with secondary MN, the measured optical density values, and hence serum anti‐α‐enolase antibody levels, were greater than the mean + 2 s.d. of healthy subjects. Immunoblot analysis showed that IgG1 or IgG3 was the predominant subclass (Th1 T helper cell type subclass) of antibodies against α‐enolase in patients with primary and secondary MN. Since circulating antibodies against α‐enolase have recently been reported in patients with various autoimmune disorders, our results suggest that a number of patients with presumed primary MN may also have abnormalities in Th1 T helper cell‐mediated immune responses.

An isoform of protein disulfide isomerase is expressed in the developing acrosome of spermatids during rat spermiogenesis and is transported into the nucleus of mature spermatids and epididymal spermatozoa.

We have purified an isoform of protein disulfide isomerase (EC 5.3.4.1) from rat liver, and raised a specific antibody against the purified protein in rabbit. Immunohistochemical studies using this antibody on rat testis sections, at both light and electron microscopic levels, showed a specific localization of the isoform of protein disulfide isomerase in the developing acrosome of the spermatids. The protein was transferred to the acrosomic vesicle from the Golgi apparatus at late Golgi phase, and remained present in the acrosome of spermatids during cap phase, acrosome phase, and maturation phase. In addition to the acrosome, the protein appeared in the nucleus of spermatids during maturation phase, and was localized in the nucleus of epididymal spermatozoa. By immunoblot analysis, almost all of the isoform of protein disulfide isomerase in the testis was found to be extractable by an isotonic buffer. On the contrary, detergent extraction was required for complete solubilization of the protein in the epididymis. These results suggest that the isoform of protein disulfide isomerase is a new intra-acrosomal soluble protein, and that the protein begins to enter the nucleus of mature spermatids in the testis and tightly binds to the nuclear components in epididymal spermatozoa.

Enucleation of human erythroblasts involves non-muscle myosin IIB

Mammalian erythroblasts undergo enucleation, a process thought to be similar to cytokinesis. Although an assemblage of actin, non-muscle myosin II, and several other proteins is crucial for proper cytokinesis, the role of non-muscle myosin II in enucleation remains unclear. In this study, we investigated the effect of various cell-division inhibitors on cytokinesis and enucleation. For this purpose, we used human colony-forming unit-erythroid (CFU-E) and mature erythroblasts generated from purified CD34(+) cells as target cells for cytokinesis and enucleation assay, respectively. Here we show that the inhibition of myosin by blebbistatin, an inhibitor of non-muscle myosin II ATPase, blocks both cell division and enucleation, which suggests that non-muscle myosin II plays an essential role not only in cytokinesis but also in enucleation. When the function of non-muscle myosin heavy chain (NMHC) IIA or IIB was inhibited by an exogenous expression of myosin rod fragment, myosin IIA or IIB, each rod fragment blocked the proliferation of CFU-E but only the rod fragment for IIB inhibited the enucleation of mature erythroblasts. These data indicate that NMHC IIB among the isoforms is involved in the enucleation of human erythroblasts.

Monoclonal immunoglobulin deposition disease associated with membranous features

BACKGROUND Very few cases of non-organized and non-Randall-type monoclonal immunoglobulin deposition disease (MIDD) associated with membranous features have been reported. Information on clinicopathological features and prognosis in this entity is limited. METHODS We reviewed 5443 renal biopsies processed at our department, and identified three patients with MIDD associated with membranous features. We evaluated clinicopathological features and outcomes in these patients. RESULTS All patients had proteinuria, and one patient developed nephrotic syndrome. Renal insufficiency was not observed. Cryoglobulin or monoclonal protein in serum and urine was not detected. A renal biopsy showed thickening of the glomerular capillary walls and spike formation. Tubulointerstitial and vascular alterations were mild or absent. Immunofluorescence studies revealed granular IgG3-kappa deposits in two patients and IgG1-kappa deposits in one patient, along the glomerular capillary walls. Immunofluorescence studies using antibodies specific for gamma-heavy chain Fab containing C(H)1 domain, C(H)2 domain and C(H)3 domain did not show any apparent deletion. On confocal microscopy, glomerular colocalization of light and heavy chains was observed. Electron microscopy showed predominant subepithelial granular deposits without distinct ultrastructural organization. All patients were treated with steroids, and good effects were observed. A follow-up renal biopsy performed in one patient showed histological improvements. No patient developed myeloma or other haematological malignancy during the course of follow-up (mean 44 months). CONCLUSIONS MIDD associated with membranous features is an extremely rare but distinctive entity. Our study suggests glomerular deposition of a nondeleted whole immunoglobulin molecule. Patients with this entity appear to respond well to steroid therapy.

Induction of Heat-Shock Proteins HSP73 and HSP90 in Rat Kidneys After Ischemia

We examined rat kidneys for serial expressions of two major heat-shock proteins (HSPs), HSP73 and HSP90, after 60 min of unilateral renal ischemia up to day 28. Immunohistochemical studies showed that HSP73 and HSP90 were rapidly induced in the cytoplasm of injured epithelial cells of the S3 segment of proximal tubules and were again induced in the cytoplasm of regenerative cells in this segment from day 3. In epithelial cells of the Henles loops, HSP90 was also induced in the cytoplasm of both injured and regenerative cells, but HSP73 was not induced in this portion. Furthermore, a transient accumulation of HSP73 into the nucleus was observed in epithelial cells of papillary collecting ducts shortly after ischemia. Serial immunoblot analysis of isotonic buffer extractable fractions from ischemic kidneys revealed the induction of both HSP73 and HSP90 in the degenerative and regenerative phases: the maximal inductions in the two phases were at 3-6 and on days 5-7, respectively. These results demonstrate that HSP73 and HSP90 are induced in injured tubular epithelial cells with a regional heterogeneity during the degenerative and regenerative phases after renal ischemia and suggest that these HSPs are involved in the process of postischemic cellular recovery.

Disappearance of nodular mesangial lesions in a patient with light chain nephropathy after long-term chemotherapy

A 64-year-old man developed multiple myeloma (kappa light chain type), nephrotic syndrome, and renal insufficiency in 1993. A renal biopsy showed typical histological findings of light chain nephropathy: nodular glomerulosclerosis with deposition of kappa light chains in the mesangial area and subendothelial space of the glomerular capillary walls. Long-term intermittent MEVP chemotherapy (melphalan, 4 mg/d for 4 days; cyclophosphamide, 100 mg/d for 4 days; vincristine, 1 mg/d; prednisolone, 40 mg/d for 4 days) diminished proteinuria and improved renal function. In April 1999, a follow-up biopsy showed remarkable diminution of nodular lesions and disappearance of kappa light chain deposits. Although the prognosis of light chain nephropathy has been considered poor, long-term successful chemotherapy can clear light chain deposits and restore renal function.

The HLA-DRB1 * 1501 allele is prevalent among Japanese patients with anti-glomerular basement membrane antibody-mediated disease

BACKGROUND We aimed to clarify the relationship between HLA-DRB1(*)1501 and anti-glomerular basement membrane (GBM) antibody-mediated disease in Japanese patients. MATERIALS Samples were collected from 16 anti-GBM antibody-positive patients who were admitted to our department or related hospitals from December 1990 to October 2005. We analysed clinical and laboratory data, kidney biopsy findings, and the HLA-DR phenotypes and HLA-DRB1 alleles of the patients. RESULTS Among the 16 patients, 15 had HLA-DR15 [the phenotype frequency (PF) was 93.8%], 7 were positive for DR4 (the PF was 43.8%) and 5 were positive for DR9 (the PF was 31.3%). The allele frequency of HLA-DRB1(*)1501 was 46.4% (13/28), which was significantly different from Japanese controls (11.6%) (P < 0.001). In contrast, the frequency of HLA-DRB1(*)1502 was not different from controls (0/28). The odds ratio of HLA-DRB1(*)1501 in these patients was 6.4 (95% CI: 2.4-16.5). CONCLUSION The present study demonstrated that Japanese patients with anti-GBM antibody-mediated disease are very likely to carry the HLA-DRB1(*)1501 but not the HLA-DRB1(*)1502 allele.

Induction and altered localization of 90-kDa heat-shock protein in rat kidneys with cisplatin-induced acute renal failure.

We purified 90-kDa heat-shock protein (HSP90) from murine brains and produced a specific antibody against the protein in a rabbit. This antibody cross-reacted with rat renal HSP90 on immunoblot analysis. Using the antibody, we observed serial immunohistochemical localizations of HSP90 in rat kidneys with cisplatin-induced acute renal failure. In normal kidneys, HSP90 was mainly localized in the cytoplasm of distal tubules and collecting ducts. Twenty-four hours after the cisplatin exposure, a rapid expression of HSP90 was observed in the cytoplasm of epithelial cells in the Henles loops (especially at the luminal side), although there was little change in these cells on light microscopy. Degenerative changes of epithelial cells appeared in the S3 segment of proximal tubules on day 3, and epithelial cell regeneration in this portion was found from day 5. On day 5, HSP90 was markedly expressed in both the cytoplasm and the nucleus of epithelial cells in the S3 segment with a granular pattern. The induced HSP90 was then accumulated in the cytoplasm of these cells on day 7 and disappeared on day 14. Immunoblot analysis of isotonic buffer-extractable renal fractions showed that there was a rapid induction of HSP90 from day 1, and that the maximum induction of HSP90 in the extract at day 5 was 6-fold that of a control. These results suggest that HSP90 plays some role related to functional abnormalities of the Henles loops at the luminal side, and in the regeneration of damaged cells in the S3 segment of proximal tubules, during the course of cisplatin-induced acute tubular injury.