Clinicopathological features and prognosis in immunoglobulin light and heavy chain deposition disease.

BACKGROUND: There are three subtypes of monoclonal immunoglobulin deposition disease: light chain deposition disease (LCDD), light and heavy chain deposition disease (LHCDD), and heavy chain deposition disease (HCDD). Although it has been considered that LHCDD is a variant of LCDD, information on clinicopathological features and prognosis in LHCDD is presently limited.

METHODS: We reviewed 5,443 renal biopsies, and evaluated clinicopathological features and outcomes in patients with LHCDD, in comparison with those in patients with LCDD and previously reported patients with HCDD. We also characterized paraprotein deposits in patients with LHCDD.

RESULTS: We identified 6 patients with LHCDD, 6 patients with LCDD, and 1 patient with HCDD. The most common clinicopathological findings in patients with LHCDD were proteinuria, renal insufficiency, and nodular sclerosing glomerulopathy. Three patients had IgG-k deposits and 3 patients had IgG-l deposits. Heavy chain subclass analysis performed in 4 patients showed IgG3 deposits in all patients. Dual immunostaining revealed glomerular colocalization of light and heavy chains. In contrast with LCDD, glomerular C3 and C1q deposits were common findings in LHCDD and HCDD. All patients with LHCDD were treated with steroids and cytotoxic agents, but no effect on proteinuria was observed. Three patients developed end-stage renal disease requiring hemodialysis. The underlying hematological disorders in LHCDD and HCDD were milder than in LCDD. Early renal survival and overall patient survival in our patients appeared to be better in LHCDD than in LCDD.

CONCLUSIONS: There are apparent differences in clinicopathological features and prognosis between LHCDD and LCDD. LHCDD is probably more similar to HCDD.