Mottl Amy K., Bomback Andrew S., Mariani Laura H., Coppock Gaia, Jennette J. Charles, Almaani Salem, Gipson Debbie S., Kelley Sara, Kidd Jason, Laurin Louis-Philippe, Mucha Krzysztof, Oliverio Andrea L., Palmer Matthew, Rizk Dana, Sanghani Neil, Stokes M.Barry, Susztak Katalin, Wadhwani Shikha, Cynthia C.: CureGN-Diabetes Study: Rationale, Design, and Methods of a Prospective Observational Study of Glomerular Disease Patients with Diabetes. Glomerular Diseases DOI 10.1159/000531679
Observational, long-term cohort studies can play an important role for generating testable hypotheses to improve our understanding of kidney disease. Selection of cases to be included in such cohort studies can be an important source of bias, making generalizations to the population questionable. Diabetic kidney disease (CKD in a patient with diabetes) is common in many regions of the world. A large diverse cohort with detailed characterization, including kidney biopsy, and prolonged follow-up would be a valuable contribution to our knowledge.
Mottl and colleagues provide the details of the ongoing CureGN-Diabetes Study which will focus on the impact of type 1 or 2 diabetes on several glomerular disorders (minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, and IgA nephropathy); only a small fraction of patients with these disorders will likely have superimposed diabetic nephropathy. The kidney biopsy information will be provided from clinically indicated rather than research biopsies, introducing an element of ascertainment bias in the study as a whole. Kidney biopsies will be analysed by reviewing electronically stored images, rendering a machine learning approach feasible. The overall goal is to better understand how diabetes modifies the pathology and outcomes of these forms of glomerular disease.
The ever-changing management of diabetes and the intrinsic heterogeneity of the glomerular disorders selected for study will likely prove to be a great challenge for data analysis and interpretation of this cohort study. Only 300 subjects will be enrolled, which may not be sufficient for appropriately stratified analysis. The degree of granularity for the analytical outcomes may be quite limited, but the goals are laudable. Time will tell. Clinicians should be encouraged to contribute patients to the cohort.