ABSTRACT
Objective To study the role of C3a and C5a in focal segmental glomerulosclerosis (FSGS) patients. Methods (1) A total of 66 patients with FSGS confirmed by renal biopsy were selected, including 18 cases of tip lesion, 11 cases of perihilar, 22 cases of not otherwise specified (NOS), 10 cases of cellular, and 5 cases of collapsing FSGS. The normal renal tissue resected from patients with kidney tumor was taken as a negative control. The expression of C3a and C5a in renal tissues was detected by immunohistochemistry. (2) Serum and urine samples from these 66 FSGS patients were collected, and serum and urine samples from 10 healthy adult selected from the same physical examination center in the same term were used as normal controls. The levels of C3a and C5a in serum and urine were detected by enzyme - linked immunosorbent assay (ELISA). Results (1) Immunohistochemical results showed that C3a and C5a were deposited in glomerulus of FSGS patients, and no deposition in normal renal tissues. The semi - quantitative score showed that kidney C3a score was significantly correlated with serum creatinine (r=0.547, P＜0.001) and 24 h urine protein (r=0.329, P=0.007) in FSGS patients, and kidney C5a score was also significantly correlated with serum creatinine (r=0.415, P＜0.001) and 24 h urine protein (r=0.414, P＜0.001) in FSGS patients. (2) The levels of serum C3a and C5a in FSGS patients were higher than those in healthy adults (both P＜0.05), but there was no significant difference among the five pathological types (P＞0.05). The levels of urinary C3a/urinary creatinine, urinary C5a/urinary creatinine were higher in FSGS patients than those in healthy adults (all P＜0.05). The levels of urine C3a/urinary creatinine and urinary C5a/urinary creatinine in collapsing FSGS were higher than other FSGS types (all P＜0.01), but there was no significant difference among the tip lesion, the perihilar, the not otherwise specified and the cellular (P＞0.05). (3) Urinary C3a/urinary creatinine levels were significantly correlated with serum creatinine (r=0.774, P＜0.001) and 24 h urine protein (r=0.430, P＜0.001) in FSGS patients, and urinary C5a/urinary creatinine levels were also significantly correlated with serum creatinine (r=0.677, P＜0.001) and 24 h urine protein (r=0.333, P=0.007) in FSGS patients. Conclusion Complement C3a and C5a may be involved in the pathogenesis of FSGS and may be related to the severity of FSGS.