Elevated serum C-reactive protein associates with deterioration of renal function in transplant recipients

Since t he elevated concentration of serum C-reactive protein (CRP) is a sensitive indicator of underlying inflammation, we investigated the association between serum CRP during the initial 6 post-transplantation months and histopathological changes in the 6-month protocol biopsies in 79 patients. We stained the biopsies for CRP and C3 to elucidate a possible role of CRP in renal injuries.

Forty patients showed no or minimal (Grade 0-1) tubular atrophy or interstitial fibrosis and 39 patients mild to moderate (Grade > or = 2) chronic histopathological changes. The latter group had had higher concentration of CRP during the first 6 post-transplant months. Because the histopathological changes predict poor long-term prognosis, we followed--from 6th month onwards--40 patients who had no or minimal histopathologic changes, and analyzed the association between CRP elevation and development of chronic allograft dysfunction. During this follow-up period (mean 51, range 14-72 months), 23 of 40 patients retained normal CRP level (Group A, mean CRP 1.12 mg/l), and 17 patients had elevated CRP concentrations (Group B, mean CRP 4.16 mg/l); 24-hour creatinine clearance improved or remained the same in all Group A patients, whereas it decreased in 7 of 17 (41%) of Group B patients (p < 0.001). In Group B patients, the annual change of creatinine clearance correlated inversely with the mean CRP concentration (r = -0.682, p < 0.01).

Our results show that histological changes in 6-month biopsies were more prominent in patients with more transplantation-associated complications, infections and frequently higher CRP levels during the initial 6 post-transplant months than in those with lower CRP levels. During post-biopsy follow-up, we found low-grade systemic inflammation--measured as elevated CRP--to associate with impairment of graft function in patients with no or minimal histological findings in 6-month biopsies, and permanently low CRP to rule out chronic allograft dysfunction.