Clinicopathological Characteristics of Light and Heavy Chain Deposition Disease: A Case Series

Rationale & ObjectiveLight and heavy chain deposition disease (LHCDD) is a rare form of monoclonal immunoglobulin deposition disease (MIDD), and limited clinical data are available characterizing this condition. We described the clinicopathological characteristics and outcomes of LHCDD.Study DesignCase series.Setting & Participants13 patients with biopsy-proven LHCDD, diagnosed between January 2008 to December 2022, at two Chinese medical centers.FindingsAmong the 13 patients described, 6 were men and 7 were women, with a mean age of 52.6 ± 8.0 years. Patients presented with hypertension (76.9%), anemia (84.6%), elevated serum creatinine (84.6%, median serum creatinine 1.7 mg/dL), proteinuria (100%, average urine protein 3.0g/24h), nephrotic syndrome (30.8%) and microscopic hematuria (76.9%). Serum immunofixation electrophoresis showed monoclonal immunoglobulin for 11 (84.6%) patients. Serum free light chain (FLC) ratios were abnormal in 11 (84.6%) patients, and heavy/light chain (HLC) ratios were abnormal in 9 of 10 (90%) patients with available data. Five patients were diagnosed with multiple myeloma. A histological diagnosis of nodular mesangial sclerosis was made in 10 (76.9%) patients. Immunofluorescence demonstrated deposits of IgG subclass (γ-κ/γ-λ:4/3) in 7 patients, and IgA (α-κ/α-λ:2/3) in 5 patients. Six patients underwent IgG subclass staining (γ1/γ2/γ3:3/2/1). The deposits of IgD-κ were confirmed by mass spectrometry in 1 patient. Among 12 patients for whom data were available over a median of 26.5 months, 11 received chemotherapy, and 1 received conservative treatment. One patient died. Three (25%) patients progressed to kidney failure. Among the 9 patients evaluable for hematological and kidney disease progression, five (56%) had a hematologic response and one (11%) achieved improvement in kidney disease.LimitationsRetrospective descriptive study, limited number of patients, UPEP or UIFE missing for most patients.ConclusionsIn this case series of LHCDD, light and heavy chain deposition in kidney tissues were most frequent with monoclonal IgG1-κ. Among patients with evaluable data, more than half had hematologic response but a kidney response was uncommon.