轻重链沉积病合并轻链淀粉样变性

Light-heavy chain deposition disease with light chain amyloidosis

中年女性,临床表现为血清肌酐升高,中等量蛋白尿、大量镜下血尿,无高血压,轻度贫血,免疫固定电泳图谱见λ型Ig G单克隆免疫球蛋白条带,骨髓细胞学检查浆细胞比例为8%。肾活检示肾小球系膜区轻-中度增宽,肾血管壁刚果红染色阳性,免疫荧光染色Ig G及λ轻链呈线状沉积于肾小球毛细血管袢及肾小管基膜,间质血管壁λ轻链阳性,超微结构见肾小球基膜内侧缘、系膜区、肾小管基膜外侧缘细沙样高密度的电子致密物沉积,免疫电镜下见电子致密物Ig G、λ轻链染色胶体金颗粒阳性,间质动脉壁淀粉丝分布;皮肤脂肪活检刚果红染色阳性。最终诊断为轻重链沉积病（Ig G-λ型）合并AL型系统性淀粉样变性（累及肾脏、皮肤、心脏）。

A 49-year-old woman presented with renal insufficiency,proteinuria,hematuria and serum monoclonal immunoglobulin Ig G-λ.Bone marrow aspirate revealed 8% plasma cells. Renal biopsy showed mild to moderate mesangial proliferation with positive Congo red staining in the vessels.Immunoflurerscence indicated linear staining along GBMs,TBMs and mesangium for λ light chains and Ig G.Ultrastructral examination showed granular electron dense deposits delineating the outer aspect of the TBMs and the endothelial aspect of the GBMs. The final diagnosis was light-heavy chain deposition disease（ Ig G-λ） with light chain amyloidosis,with kidney,skin and heart involved.