Background: Susceptibility to infections is a major cause of high morbidity and mortality in patients with chronic kidney disease (CKD). Polymorphonuclear leukocytes (PMNs) play a major role in the host defense against various infections. Although the phagocytic function of PMNs in uremic patients has been subjected to repeated evaluation, results have been inconsistent. Also, the effects of progressive uremia and acute hemodialysis (HD) on polymorphonuclear function have been scarcely evaluated.
Methods: In this study, we assessed the phagocytic index (PI) of PMNs following their uptake of IgG-coated sheep erythrocytes in patients with varying severity of CKD and in healthy controls. In patients with advanced renal failure, the effects of acute HD on PI pre- and post-HD were also studied.
Results: A total of 30 patients with CKD and 15 healthy controls were studied. Patients with CKD were categorized into two groups: mild to moderate renal failure (S. Creatinine 2-6 mg/dL) and advanced renal failure (S. Creatinine >6 mg/dL) (n=15 for each). All three groups were age and sex matched. Patients with advanced renal failure had significantly impaired PI (4.03 +/- 1.15) as compared to patients with mild to moderate renal failure (7.17 +/- 2.62) and normal controls (8.13 +/- 3.31) (p < 0.001 for both). There was a statistically insignificant decline in the PI in patients with mild to moderate RF when compared to controls (7.17 +/- 2.62 versus 8.13 +/- 3.31). In patients with advanced renal failure, acute HD led to a significant improvement in PI (5.52 +/- 1.55 versus 4.03 +/- 1.15, p < 0.01).
Conclusion: In patients with CKD, there is a progressive decline in the phagocytic index of the PMNs with increasing severity of uremia. Significant improvement in the phagocytic index following acute hemodialysis suggests the role of a circulating uremic toxin in this PMN dysfunction.