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Biomedical subjects

M Kuwana

Publications and source records attributed to M Kuwana.

At least 91 records · Page 5Linked to original sources
PubMed1995

[Clinical subsets and phospholipid-dependent anti-beta 2-glycoprotein I antibodies in antiphospholipid syndrome].

Clinical significance of IgG phospholipid-dependent anti-beta 2-glycoprotein I (beta 2-GPI) antibodies in patients with antiphospholipid syndrome (APS) was studied. The subjects consisted of 14 patients with primary APS (PAPS) and 32 with secondary APS based on SLE. IgG phospholipid-dependent anti-beta 2-GPI antibodies were examined by ELISA. Incidences of malar rash, arthritis, renal disorder, leucopenia, immunological disorder, and hypocomplementemia were significantly less frequent in patients with PAPS than in those with secondary APS based on SLE. However, sustained positive reactions of IgG anticardiolipin antibodies were found in 86% of patients with PAPS. Frequency of IgG phospholipid-dependent anti-beta 2-GPI antibodies was significantly higher in patients with PAPS (100%) than in those with secondary APS (34%). Moreover, titer of IgG phospholipid-dependent anti-beta 2-GPI antibodies was significantly higher in patients with PAPS than in those with secondary APS. These data indicated that IgG phospholipid-dependent anti-beta 2-GPI antibodies are useful for identifying a subset in patients with APS as well as for studying the mechanism of thrombotic events in these patients.

Adult↗
PubMed1994

Association of autoantibodies to topoisomerase I and the phosphorylated (IIO) form of RNA polymerase II in Japanese scleroderma patients.

Autoantibodies to RNA polymerases (RNAP) I and III are highly specific for scleroderma (SSc), whereas autoantibodies to RNAP II are associated with systemic lupus erythematosus (SLE) and overlap syndromes, as well as SSc. The specificities of autoantibodies to RNAP I, II, and III in 129 SSc sera were investigated in the present study. Immunoprecipitation and pulse-chase analysis demonstrated several patterns of autoantibody recognition of RNAPs. Some sera immunoprecipitated RNAP II only after its largest subunit was phosphorylated, suggesting that they contained autoantibodies that recognized an epitope carrying a phosphoamino acid. Autoantibody recognition of all three classes of RNAPs was influenced strongly by race. Although in SLE, autoantibodies to the phosphorylated form of RNAP II (RNAP IIO) were identified in all races, in SSc, these autoantibodies were seen in 21% of Japanese and 5% of Black patients, but never in Caucasians. A striking association of anti-RNAP IIO with anti-topoisomerase I (topo I) autoantibodies was found in Japanese and Black SSc, but not SLE, patients. However, anti-topo I Abs were not associated with anti-RNAP IIO in Caucasians. Japanese SSc patients who were positive for both anti-RNAP IIO and anti-topo I Abs had a significantly higher frequency of diffuse disease, pigmentation changes, flexion contractures, and acro-osteolysis than patients having autoantibodies to topo I alone, and were diagnosed at a younger age (p < 0.05). These data suggest that genetic factors (possibly HLA-linked) influence autoantibody specificity, and that different autoantibody fine specificities may either cause, or be predictive of, different clinical outcomes.

Adult↗
PubMed1994

Clinical and prognostic associations based on serum antinuclear antibodies in Japanese patients with systemic sclerosis.

OBJECTIVE: To clarify the clinical features and prognosis of systemic sclerosis (SSc) based on serum antinuclear antibodies (ANA). METHODS: We studied 275 consecutive Japanese patients newly diagnosed as having SSc, who were first evaluated during the period 1971-1990. Eight SSc-related ANA were identified using indirect immunofluorescence, double immunodiffusion, or immunoprecipitation assays. Clinical and prognostic features were retrospectively analyzed in patient groups, categorized by their serum ANA. RESULTS: Cumulative survival rates at 10 years after diagnosis of SSc were 93% in patients with anticentromere antibodies (ACA), 72% in those with anti-U1 RNP, 66% in those with anti-DNA topoisomerase I (anti-topo I), and 30% in those with anti-RNA polymerases I, II, and III (anti-RNAP). Major organ involvement linked to cause of death included biliary cirrhosis in patients with ACA, isolated pulmonary arterial hypertension and cerebral hemorrhage in those with anti-U1 RNP, pulmonary interstitial fibrosis in those with anti-topo I, and cardiac and renal involvement in those with anti-RNAP. CONCLUSION: Determinations of serum ANA in SSc patients are useful in predicting organ involvement and long-term outcome.

Adolescent↗
PubMed1994

Racial differences in the distribution of systemic sclerosis-related serum antinuclear antibodies.

OBJECTIVE: To determine racial differences in the frequencies of systemic sclerosis (SSc)-related serum antinuclear antibodies (ANA). METHODS: We tested serum samples from 275 Japanese, 416 North American Caucasian, and 24 North American black SSc patients for 8 SSc-related serum ANA, using indirect immunofluorescence, double immunodiffusion, and radioimmunoprecipitation assays. RESULTS: In comparing the 3 racial groups, we found that anti-U1 RNP, anti-RNA polymerase I, II, and III, and anti-U3 RNP antibodies were the most frequently detected antibodies in Japanese, Caucasian, and black patients, respectively. Anti-PM-Scl antibody was found exclusively in Caucasians. CONCLUSION: The production of SSc-related serum ANA is related to immunogenetic background.

Antibodies, Antinuclear↗
PubMed1994

Genetic and immunological differences between Japanese patients with diffuse scleroderma and limited scleroderma.

OBJECTIVE: To study the association between HLA-DR and scleroderma (SSc), subsets of SSc, and autoantibodies in SSc. METHODS: HLA-DR antigens were determined in 45 Japanese patients with SSc. The association between HLA-DR and SSc, subsets of SSc, and autoantibodies was analyzed in 22 patients with SSc excluding mixed connective tissue disease (MCTD)/overlap syndrome (OL). RESULTS: When the 20 patients with MCTD and 3 patients with OL were excluded from the original patient group, a significant increase of HLA-DR2 was observed (59 vs 29% of controls, p < 0.01). The frequency of DR2 increased to 69% in patients with diffuse SSc (p < 0.01). DR1, which was not found in diffuse SSc, was found in 2 of 9 patients with limited SSc. The frequency of DR2 was significantly higher in patients with antitopoisomerase I (10/12, 83%, p < 0.05). In contrast, DR1 was found only in 2 patients with anticentromere antibodies (ACA), and all 5 patients with ACA had no HLA-DR2 (p < 0.01). CONCLUSION: Our results suggest that different HLA-DR markers may be associated with the production of distinct autoantibodies in diffuse SSc and limited SSc.

Antibodies↗
PubMed1993

Autoantigenic epitopes on DNA topoisomerase I. Clinical and immunogenetic associations in systemic sclerosis.

OBJECTIVE: To elucidate the clinical and immunogenetic associations with reactivity to autoantigenic epitopes on DNA topoisomerase I (topo I) recognized by sera from patients with systemic sclerosis (SSc). METHODS: Autoantigenic epitopes on topo I were identified by screening an epitope library constructed from topo I complementary DNA restriction fragments using autoimmune anti-topo I-positive sera as a probe. Epitope reactivities of sera from 43 anti-topo I-positive SSc patients were surveyed by immunoblotting, and associations with clinical symptoms and HLA-DR types were examined. RESULTS: Four different epitope regions were identified on the topo I molecule. Immunoreactivity to the region encompassing amino acid residues 658-700, termed ER4, was found to be associated with diffuse cutaneous SSc, progressive pulmonary interstitial fibrosis, and poor prognosis for 15-year survival. SSc patients with ER4 reactivity frequently displayed the DR2/DRw52 phenotype. CONCLUSION: Molecular analysis of precise antigenic epitopes on topo I is helpful in classifying clinical subsets of SSc.

Adult↗
PubMed1993

Cytosolic protein phosphatase may turn off activated NADPH oxidase in guinea pig neutrophils.

Protein phosphatase inhibitors, okadaic acid and calyculin A, potentiated and elongated N-formyl-methionyl-leucyl-phenylalanine-induced superoxide anion (O2-) production in guinea pig neutrophils. The activity of NADPH oxidase in the membrane fraction prepared from phorbol 12-myristate 13-acetate-stimulated neutrophils was inactivated by the addition of the cytosol from resting neutrophils, such inactivation of NADPH oxidase was also suppressed by the protein phosphatase inhibitors. We previously reported that phosphorylation of the 46-kDa protein by protein kinase C is one of the activation mechanisms of NADPH oxidase-dependent superoxide anion production. In the cytosol fraction, we found protein phosphatase activity that catalyzed dephosphorylation of 32P-labeled phosphoproteins including the 46-kDa protein. Dephosphorylation of the 46-kDa protein was inhibited by the addition of okadaic acid and calyculin A. These results indicate that dephosphorylation of the 46-kDa protein by protein phosphatase is involved in the inactivation of NADPH oxidase. NADPH oxidase activity in guinea pig neutrophil may be regulated by the phosphorylation/dephosphorylation state of the 46-kDa protein by protein kinase C and protein phosphatase.

Animals↗
PubMed1993

Autoantibody reactive with three classes of RNA polymerases in sera from patients with systemic sclerosis.

We have identified a novel autoantibody reactive with all three classes of RNA polymerases, well-characterized nuclear enzymes, in sera from patients with systemic sclerosis (SSc). After incubation with [35S]methionine-labeled HeLa cell extracts, 14 of 275 SSc sera immunoprecipitated 12 or 14 proteins with similar molecular weights as those of several subunit proteins of eukaryotic RNA polymerases I, II, and III. Purified IgG from these two types of sera inhibited RNA transcription catalyzed by RNA polymerases I, II, and III in vitro. Immunoblot analysis using RNA polymerase-enriched fraction showed that the majority of these sera reacted with 42- or 25-kD protein. Anti-RNA polymerase antibody was highly specific to SSc, especially to diffuse cutaneous SSc. Clinical features associated with this antibody included a high frequency of heart and kidney involvement and a poor survival rate at 5 yr after first visit. These findings indicate that the autoantibody to three classes of RNA polymerases is a new marker for a unique subset of diffuse cutaneous SSc.

Antibodies, Anti-Idiotypic↗
PubMed1993

The HLA-DR and DQ genes control the autoimmune response to DNA topoisomerase I in systemic sclerosis (scleroderma).

HLA class II alleles were determined using the PCR-RFLP method in Japanese systemic sclerosis (scleroderma) patients with (n = 28) or without (n = 34) anti-topoisomerase I antibodies (anti-topo I). Either the DQB1*0601 or *0301 allele was recognized in all anti-topo I positive patients, compared with 44% of anti-topo I negative patients (P < 0.00001, relative risk [RR] > 41) or 58% of Japanese healthy control subjects (P < 0.00001, RR > 24). Tyrosine at position 26 in the second hypervariable region in the beta 1 domain of the DQB1 gene is common to these two alleles and is not present in any other known DQB1 alleles. We also examined immunoreactivities of anti-topo I positive sera to four different autoantigenic B cell epitopes of topo I molecule that were expressed as recombinant fusion proteins. One major B cell epitope, located within the region corresponding to amino acid residues 74-248, was perfectly associated with the amino acid sequence FLEDR at positions 67-71 in the beta 1 domain of the DRB gene. Two other epitopes, corresponding to 316-441 or 658-700, were associated with the serologically defined HLA-DR52 antigen. Patients with both FLEDR and DR52 demonstrated higher anti-topo I antibody titers. These results suggest that the HLA-DR and DQ genes together control the autoimmune response to topo I in systemic sclerosis.

Amino Acid Sequence↗
PubMed1993

[Distribution of cofactor-dependent anti-cardiolipin antibodies in collagen diseases].

Cofactor-dependent IgG anti-cardiolipin antibodies (ACA) were examined in sera from various connective tissue diseases by ELISA using purified human beta 2-glycoprotein I. The frequency and titer of cofactor-dependent IgG ACA were higher in patients with SLE than in those with other diseases, such as RA, SSc, PM/DM, overlap syndrome, and MCTD. The predictive value for SLE was 95%. However, all of the ACA were not cofactor-dependent in SLE patients. These results indicated that cofactor-dependent IgG ACA were specific for SLE patients, but the epitopes of ACA were heterogenous, depending on various clinical manifestations.

Antibodies, Anticardiolipin↗
PubMed1992

Specificity of antibodies to single-stranded (ss) DNA in SLE patients with anti-phospholipid syndrome.

Although the concept of anti-phospholipid syndrome has been proposed in patients with SLE and other rheumatic diseases, the immunological mechanism is still controversial. Recently, the crossreactivity between anti-cardiolipin antibody and anti-ssDNA antibodies has been discussed in relation to this syndrome. In the present study, the specificity such as the avidity and the crossreactivity of anti-ssDNA antibodies was examined to find a clue to clarify the question why all of anti-cardiolipin antibody positive patients do not have any specific clinical features, thrombosis and spontaneous abortion. The avidity of IgG anti-ssDNA antibodies was examined by salt elution studies in solid phase ELISA. The avidity of anti-ssDNA antibodies tended to be lower in 10 patients with specific features than in other 10 patients without those features. The crossreactivity of affinity purified IgG anti-ssDNA antibodies was investigated by competitive ELISA. Purified anti-ssDNA antibodies from 4 patients without specific features were slightly inhibited by negatively charged phospholipids, cardiolipin and phosphatidylserine, whereas purified anti-ssDNA antibodies from 2 patients with specific features, who were considered to have anti-phospholipid syndrome, were little inhibited by these phospholipids. The above results suggest that the specificity of anti-ssDNA antibodies appears, at least partly, in different manners whether specific features are present or absent in anti-cardiolipin antibody positive patients. Moreover, anti-ssDNA antibodies and anti-phospholipid antibodies may form separate groups of antibodies in patients with anti-phospholipid syndrome.

Antibody Specificity↗
PubMed1992

Initial predictors of survival in patients with systemic sclerosis (scleroderma).

We conducted a retrospective study of 86 patients with systemic sclerosis (SSc) to clarify the initial predictors of survival at the first visit to the hospital. A life-table analysis of survival was performed concerning 137 items from their histories, physical examinations, and laboratory data. The observed cumulative survival rates were 78.0 percent at 5 years and 68.2 percent at 10 years. Ten items were found to be the initial predictors of survival in patients with SSc. Of these 10 items, 9 items showed significant differences within 5 years of the first visit to the hospital. Patients with resting electrocardiographic abnormalities, such as atrial or ventricular arrhythmias, or conduction disturbances, pulmonary fibrosis on the chest x-ray films, or decreased vital capacity had significantly lower survival rates. However, patients with anti-centromere antibody had a significantly better survival rate. In addition, males, aged patients over 65 years old, and patients with proteinuria, leucopenia, or hypergammaglobulinemia had significantly lower survival rates. Only patients with proximal scleroderma at the first visit to the hospital had a significantly lower survival rate after 8 years. These results are useful in predicting individual patients at risk of shortened survival and in managing these patients.

Adolescent↗
PubMed1992

[A case of Wegener's granulomatosis with necrotizing granuloma limited to intraorbital lesions].

A patient of Wegener's granulomatosis (WG) who developed intraorbital tumor without pulmonary and renal involvement was reported. A 52-year-old male has suffered from visual disturbance and right proptosis. Administration of betamethasone resulted in a temporary relief of his symptoms. However, following the reduction of steroid dosage, severe recurrence of ocular symptom occurred and his right sight was completely lost. On admission to our hospital, there were swollen eyelids and saddle nose. The CT scan demonstrated intraorbital tumors bilaterally associated with chronic sinusitis. The repeated biopsies of nasal mucosal lesions disclosed presence of a giant cell granuloma with necrotizing vasculitis. A diagnosis of WG had been made, so intermittent high-dose intravenous cyclophosphamide therapy were initiated. The size of the bilateral intraorbital tumors reduced with continuous cyclophosphamide therapy. At the last observation during 22 months after the initiation of cytotoxic therapy, there was no evidence of clinical and radiological recurrence. Three cases of WG with intracranial tumors in our hospital showed multiple cranial nerve palsy and poor response to corticosteroid therapy. The "limited form" without renal involvement has been known as a subset of WG with a relatively good prognosis. This report suggest the existence of further limited form with intracranial granuloma as a cardinal presentation of WG. Although the extent of granulomatous lesions are limited and progression is slow, the treatment by corticosteroid alone is not sufficient and as the systems form of WG, combined therapy with cyclophosphamide appeared to be indicated.

Betamethasone↗
PubMed1992

[Clinical significance of anti-nucleolar antibodies detected by immunoprecipitation method in patients with systemic sclerosis].

We have characterized a clinical significance of anti-U3RNP, anti-7-2RNP, anti-RNA polymerase I and anti-PM-Scl antibody, autoantibodies to nucleolar proteins detected by immunoprecipitation method in patients with systemic sclerosis (SSc). In 248 patients with SSc, anti-U3RNP antibody was positive in 9 (3.6%), anti-7-2RNP antibody was positive in 7 (2.8%) and anti-RNA polymerase I antibody was positive in 3 (1.2%). But none of 248 patients was positive for anti-PM-Scl antibody. Anti-U3RNP antibody positive SSc patients showed significantly lower frequency of joint and lung involvements, compared with anti-U3RNP antibody negative SSc patients. Anti-7-2RNP antibody was found only in patients with limited scleroderma. The anti-7-2RNP antibody could be detected before appearance of skin thickening, so this indicate the usefulness of detecting anti-7-2RNP antibody in the early stage of SSc. Two of 3 anti-RNA polymerase I antibody positive patients were classified as diffuse scleroderma. All anti-RNA polymerase I antibody positive patients had high incidence of internal organ involvements including lung, heart and kidney, so two of these patients died of heart failure. These data showed the close clinical association of antigenic specificities of anti-nucleolar antibodies analysed by immunoprecipitation method, and indicated the usefulness of detecting these anti-nucleolar antibodies in subgrouping of patients with SSc.

Adult↗