Evidence for Abundant Presence of Chymase-Positive Mast Cells in the Kidneys of Patients with Immunoglobulin A Nephropathy: Effect of Combination Therapy with Prednisolone and Angiotensin II Receptor Blocker Valsartan

Several investigators have reported chymase-positive mast cells in tubulointerstitial damage. However, the significance of the presence of chymase in the pathophysiology of renal diseases is unclear. We investigated relationships among chymase, renal damage, and intra-renal circulation. The participant pool consisted of 52 patients with immunoglobulin A (IgA) nephropathy who underwent renal biopsy. Of these, 18 were examined before and 2 months after the initiation of treatment with prednisolone alone ( n =9) or combined with the angiotensin II receptor blocker valsartan ( n =9). Biopsied renal specimens were evaluated, and the degree of renal circulation (resistive index; RI) was calculated by measuring flow velocity using Doppler sonography. The number of chymase-positive mast cells as visualized by immunohistochemical staining correlated significantly with both tubulointerstitial damage (ρ = 0.69, p < 0.001) and RI ( r = 0.52, p