Sojiro Ogino

Electron-Microscopic and Inimunohistochemical Study of Beta-2-Microglobulin-Related Amyloidosis

beta 2-Microglobulin (beta 2-MG)-related amyloidosis has been reported as a complication in long-term hemodialysis patients. We observed beta 2-MG amyloid deposits in synovial sheaths, bone cysts and gastric mucosa. They showed unique ultrastructural features, that is bundles or nodules consisting of curved or linear amyloid fibrils, associated with various cell reactions. The electron-microscopic histochemical study showed that they strongly stained with periodic acid-silver methenamine stain. A similar phenomenon was noticed in the spicules or bundles of amyloid fibrils in primary and secondary renal amyloidosis. With the cationic reagent toluidine blue 0, proteoglycan-like structures were observed around amyloid bundles and nodules, but not on each fibrils. Based on these results, we postulate that there is a close relationship between ultrastructural features and histochemical characteristics in beta 2-MG amyloid fibrils.

No linkage to the COL4A3 gene locus in Japanese thin basement membrane disease families

Summary: Patients with thin basement membrane disease (TBMD) exhibit persistent haematuria with a diffuse thinning of the glomerular basement membrane (GBM), especially of the lamina densa. It appears to be an autosomal dominant trait. It has been reported that the Goodpasture epitope, which is located in the non‐collagenous domain of type IV collagen α 3 chain, may be reduced in patients with TBMD. We speculated that the candidate gene for TBMD could be the type IV collagen α 3 chain gene (COL4A3), which is present closely to type IV collagen α 4 chain gene (COL4A4) on chromosome 2q35–37. We conducted a linkage analysis to investigate the relationship between familial TBMD and COL4A3 gene, using COL4A3 cDNA polymorphism and a (CA)n microsatellite marker located in the COL4A3 gene. We examined 32 individuals from four Japanese families with TBMD. There were no associations between the patients with haematuria and certain alleles of the two markers in the pedigrees of three families. It has been reported that type IV collagen α 1 chain gene (COL4A1) and α 2 chain gene (COL4A2) are not involved in TBMD, and that α 5 chain gene (COL4A5) and a 6 chain gene (COL4A6) map to chromosome X. In conclusion, our findings suggested that familial TBMD is not caused by the genetic abnormalities of type IV collagen genes isolated thus far.

Clinicopathological study for renal disorders of patients with rheumatoid arthritis.

慢性関節リウマチ(RA)の腎障害を臨床病理学的に検討した.組織検索80例中,微小変化10例,メザンギウム増殖性糸球体腎炎21例(局所性変化7例,び漫性変化14例)は,血尿主体の尿異常を呈し,腎機能は良好であった.膜性腎症は8例で, 3例は特殊薬物の使用がなかった.アミロイドーシス合併は14例で,尿異常,腎機能低下が著明であった.膠原病重複は13例で,抗DNA抗体高値や低補体血症を高頻度に認めた.なお,螢光抗体法で,び漫性増殖性糸球体腎炎を中心に14例がIgA腎炎と診断され,また電顕的に糸球体基底膜のび漫性菲薄化を9例に認め,全例金療法歴を有していた. RAには多彩な腎病変が認められ,関節外症状として重要と思われた.