Al‐Rabadi, Laith

Here, we used digital spatial profiling (DSP) to describe the glomerular transcriptomic signatures that may characterize the complex molecular mechanisms underlying progressive kidney disease in Alport syndrome, focal segmental glomerulosclerosis, and membranous nephropathy. Our results revealed significant transcriptional heterogeneity among diseased glomeruli, and this analysis showed that histologically similar glomeruli manifested different transcriptional profiles. Using glomerular pathology scores to establish an axis of progression, we identified molecular pathways with progressively decreased expression in response to increasing pathology scores, including signal recognition particle–dependent cotranslational protein targeting to membrane and selenocysteine synthesis pathways. We also identified a distinct signature of upregulated and downregulated genes common to all the diseases investigated when compared with nondiseased tissue from nephrectomies. These analyses using DSP at the single-glomerulus level could help to increase insight into the pathophysiology of kidney disease and possibly the identification of biomarkers of disease progression in glomerulopathies.

A patient presented with neuromuscular, respiratory and cardiac symptoms and was initially diagnosed with amyotrophic lateral sclerosis (ALS), myocardial ischaemia and pneumonia. He developed unexplained progressive kidney failure over the ensuing week, and his kidney biopsy showed thrombotic microangiopathy that led to the correct diagnosis of normotensive scleroderma renal crisis. His clinical presentation and course were consistent with systemic sclerosis and normotensive scleroderma renal crisis. He was treated with an ACE inhibitor (ACEi) and haemodialysis with significant functional improvement over the next 3 months to his prior baseline with the exception of kidney failure. This case highlights a diagnostic challenge requiring astute history and physical examination skills, and the value of a kidney biopsy in providing the final diagnosis.