Comparative analysis of primary and secondary glomerulopathies in the northeast of Brazil: data from the Pernambuco Registry of Glomerulopathies - REPEG.

INTRODUCTION: In Brazil, glomerulopathies are the third leading cause of chronic renal disease, accounting for 11% of dialysis patients. Studies on the prevalence of this disease in Northeastern Brazil are scarce. OBJECTIVE: The aim was to describe the findings of biopsies and to conduct a comparative analysis on the clinical laboratory presentation of primary glomerulopathies (PG) and secondary glomerulopathies (SG). METHODS: This was a retrospective study conducted at two public teaching hospitals in the state of Pernambuco, Northeastern Brazil. RESULTS: A total of 1151 biopsies performed between 1998 and 2016 were analyzed. The sample consisted of 670 biopsies of native kidneys, after excluding extra glomerular diseases and unsuitable material. PG were more frequent than SG (58% vs. 42%). There was a prevalence among PG of focal segmental glomerulosclerosis (43%). Membranoproliferative glomerulonephritis and collapsing glomerulopathy, accounted for 9% and 3% of the PG, respectively. For SG, the main etiologies were lupus nephritis (67%) and infections (10%). Female sex, hematuria and an elevated level of creatinine were related to a greater chance of SG, at multivariate analysis. An increase of proteinuria reduced this chance. Nephrotic syndrome was more common among the PG, while urinary abnormalities and nephritic syndrome prevailed in patients with SG. CONCLUSION: This is the first registry of glomerulopathies in Northeastern Brazil. It also presents a comparative analysis of the main clinical laboratory abnormalities of PG and SG, and includes the current classifications of glomerular diseases.