ObjectiveLight chain deposition has been shown to be an important histologic hallmark with differences in isotype, characteristics and ratio of kappa and lambda light chains having a significant role in pathobiology, pathogenesis and prognosis of several glomerular diseases. However, there is, to the best of our knowledge, no study dedicated to evaluating light chain deposits in patients with lupus nephritis (LN).MethodsWe have conducted a retrospective cohort study to evaluate the characteristics and prognostic significance of light chain deposition profile in the kidney of subjects with LN. We have collected data on demographics, clinical and laboratory parameters and histopathology (light, immunofluorescent and electron microscopy). Lambda domination (LD) was defined as lambda intensity – kappa intensity ≥ +1. SLE was diagnosed using the ACR criteria and renal outcomes per KDIGO.ResultsA total of 56 patients with LN were followed up for at least one year after kidney biopsy (79% women, mean age at biopsy 38±13 years). Mean number of glomeruli per biopsy sample was 26±12. A total of 42 (75%) patients had light chain deposition in the glomerulus with 4 (7%) having restricted lambda chain deposition and none had restricted kappa chain deposition. Mean immunofluorescent intensity was 1.6±1.0 for lambda and 1.8±1.0 for kappa light chain. A total of 12 (21%) patients had LD in the glomerulus. When examining renal outcomes at one year post-biopsy, 55% of patients achieved complete response (CR), 30% achieved partial response (PR) and 15% had no response. There were no differences in achievement of remission (CR or PR) between patients with vs. without light chain deposition (88% vs. 71%, p=0.60) as well as between those with vs. without LD (90% vs. 83%, p>0.99).ConclusionLight chain deposition is prevalent in LN, but LD is much lower than in IgA nephropathy. While their deposition did not affect renal outcomes in our patients, light chains are an important factor to consider in LN patients, especially where restriction is present and further work-up, primarily for hematologic disease, is needed. Further investigation of the potential effect of pathobiologic characteristics of light chains in LN is warranted.