Total lymphocyte count in peripheral blood of peritoneal dialysis patients: relationship to clinical parameters and...

Total lymphocyte count (TLC) is used as a nutritional status measurement. The impact of TLC on mortality in peritoneal dialysis (PD) patients is controversial. This study aimed at evaluating the effect of TLC on mortality, and assessing the relationship between TLC and nutritional status, anemia and erythropoietin (EPO) response, acute-phase response, dialysis adequacy and volume status in PD patients.

Seventy-three PD patients were monitored for 3 yrs from the beginning of the treatment. Data recorded for each patient included demographic features, comorbidity, TLC, blood biochemistry, systolic and diastolic blood pressures (BP), indices of dialysis adequacy and nutritional status, total fluid removal and mortality. Adjusted mortality risk for TLC was estimated using the Cox's regression models composed by TLC and one covariate having a value p<0.05 in univariate analysis.

The 3-yr patient survival rates were significantly different among the TLC quartiles. The adjusted TLC was found, generally, to be a significant predictor of death in reduced Cox's models, except in models composed of TLC and total fluid removal or serum albumin. The receiver operating characteristics (ROC) analysis demonstrated that TLC provided a significant prediction of mortality. TLC correlated positively to total fluid removal, serum albumin, triglyceride and hematocrit, and negatively correlated to BP, high peritoneal transport and EPO-need. It did not correlate to other measures of nutritional status, dialysis adequacy and acute-phase response. Fluid removal and serum triglyceride were independent predictors of TLC in multivariate analysis.

Our findings suggest that TLC can be used as a simple prognostic tool in PD patients; however, the association between TLC and mortality is confounded by other prognostic factors. Volume status could be a more important factor affecting the TLC than nutritional status.