Total lymphocyte count: A promising prognostic index of mortality in patients on CAPD

Objective: In view of the limitations of albumin in peritoneal dialysis (PD ), we set out to evaluate whether total lymphocyte counts (TLC) could serve as a better prognostic indicator. We were also interested in how these par ameters might differ between PD and hemodialysis (HD) patients. Design: In a retrospective study, we reviewed 113 charts from our dialysis unit. All laboratory analyses were performed by the Department of Clinical pathology of the Nassau County Medical Center, using standard procedures. I ntact parathyroid hormone (PTH) was sent out to Nichols Laboratories. Setting: All patients originated from the renal clinic at Nassau County Med ical Center, a 612 bed public hospital. Patients:The 38 PD and 75 HD patients selected had been receiving dialysis for at least 12 months and up to 3 years. The PD patients received either c ontinuous ambulatory and/or cycler PD. For the survivors, the averages of t heir routine chemical analyses were considered their representative values. For the nonsurvivors, the most recent laboratory values prior to their end point were considered. Main Outcome Measures: Mortality or apparent malnutrition leading to transf er to HD represented the end points for PD patients. Mortality alone was us ed as the end point for HD patients. Results: Within the PD population, serum albumin was not significantly lowe r in nonsurvivors compared to survivors, while the TLC was significantly lo wer in nonsurvivors (1277 +/- 146/mm(3) vs 2249 +/- 236/mm(3), p = 0.0036). The HD population demonstrated a significant difference in both TLC and se rum albumin levels between its two prognostic groups; albumin was the bette r discriminator. Nonsurvivors had a 20% lower serum albumin than did the su rvivors (27.0 +/- 1.6 g/L vs 34.0 +/-: 0.5 g/L, p = 0.0001). Patients on PD had a higher TLC than those on HD (p = 0.0001). Conclusions: In the HD population, but not in the PD population, both serum albumin and TLC were significantly higher in the group that survived. Seru m albumin is a more powerful discriminator of mortality in the HD populatio n, while TLC is a better discriminator of mortality in the PD population. F or uncertain reasons, PD patients have a higher TLC than those on HD.