Biopsy eosinophilia as a predictor of renal graft dysfunction.

AIM: The aim of this research was to assess the impact of eosinophilia in renal biopsy specimens obtained during an acute rejection (AR) episode on the severity and reversibility of rejection and on long-term graft function. MATERIAL: Among 165 renal graft recipients who underwent transplantation (Tx) in 2001 and 2002 whose biopsy specimens revealed AR, 49 with tissue eosinophilia were compared with control group of 48 without this feature. The average biopsy time was 60.6 and 95.8 days, respectively. Biopsies during delayed graft function were performed in 46.9% of patients with eosinophilia and 29% in the control group. The immunosuppressive regimen was based on tacrolimus or cyclosporine. RESULTS: Tissue eosinophilia was observed in 49 of 165 patients (29.6%): 5 patients had eosinophilia <10/mm(2), 31 patients 10-100/mm(2), 13 patients >100mm(2) (3 patients >300/mm(2)). Severity of AR according to Banff score was statistically lower in the control group (P <.002). Patients with tissue eosinophilia who initially received steroid-free treatment presented with significantly higher (P =.02) biopsy/patients index (2.3 vs 1.81) than the total eosinophilic group. Serum creatinine values at 6 and 12 months after transplantation (Tx) were higher among eosinophilic when compared with the control group (2.41 vs 1.82 mg/dL, P <.002; 2.10 vs 1.98 mg/dL, P =.006, respectively). Chronic rejection within the first year occurred in 25% of patients with tissue eosinophilia, and 8.3% of patients in the control group. One-year graft survival rate among patients with tissue eosinophilia was lower compared with the control group (89.8% and 93.7%, respectively). CONCLUSIONS: Biopsy eosinophilia is a negative predictor that indicates a more severe course of AR and a worse response to treatment with the threat of chronic graft dysfunction.