Wang Shujie, Hu Danni, Li Yue-Qiang, Lei Qing, Liu Liu; He Xiaofeng, Han Min, Pei Guangchang, Zeng Rui, Xu Gang.: High Renal Mast Cell Density Is Associated with Poor Prognosis in Patients with Immunoglobulin A Nephropathy. American Journal of Nephrology DOI 10.1159/000531243
The search for clinical, laboratory, and histological biomarkers useful for predicting outcomes in IgA nephropathy (IgAN) continues at a fairly rapid pace, but actual progress is modest at best.
Wang and co-workers add to the literature on this interesting topic by examining kidney mast cell density in kidney biopsies showing IgAN. Seventy-six Chinese patients with IgAN (all studied between 2007 and 2010) and followed for an average of 8 years were included. Mast cell density (tryptase + cells) in tubule-interstitium was compared to outcomes of kidney function.
Increased mast cell density, particularly when associated with more severe clinical or histological manifestations, was predictive of poor outcomes in a multi-variate Cox regression model. Mast cell density showed prediction of progression (doubling of serum creatinine) independent of clinical and histological parameters. Only tryptase + cells were counted. Chymase + mast cells were not studied. Increased mast cell density was also associated with more intense C3 deposition in glomeruli.
This is a small series and needs replication in a larger and more geographically diverse population. Whether the finding of increased mast cell density should be utilized to make therapeutic decisions cannot be determined by a study of this design.