Clinicopathological characteristics of primary immunoglobulin A nephropathy with immunoglobulin M deposition

IntroductionImmunoglobulin (Ig) G deposition in patients with IgA nephro­pathy (IgAN) often indicates poor prognosis, but the relationship between IgM deposition and the clinicopathology of IgAN remains controversial. The purpose of this study is to further understand the relationship between IgM deposition and IgAN, so as to provide a basis for clinical evaluation and treatment.Material and methodsWe included a total of 839 IgAN patients from the nephropathy departments of 2 hospitals; there were 162 IgM-positive patients and 677 IgM-negative patients. Clinical and pathological data were retrospectively analysed. In addition, a multifaceted comparison was made between the IgM-positive group and the IgM-negative group.ResultsThe serum albumin and IgG levels of the IgM-positive group were lower than those of the IgM-negative group, and the levels of low-density lipo­protein, 24 h proteinuria, and IgM were higher than those of the IgM-nega­tive group. The proportion of endothelial cell proliferation (E1), segmental sclerosis or adhesion (S1), and renal tubular interstitial score in the IgM-posi­tive group were all higher than those in the IgM-negative group. Immunofluo­rescence results showed that the proportion of IgM-positive combination and IgG and C1q deposition was higher than that in the IgM-negative group.ConclusionsImmunoglobulin A nephropathy patients with IgM deposition have relatively poor clinical biochemical indicators, and the degree of renal pathological damage is also relatively serious.