Nephrol Dial Transplant (2003) 18: 1181-1189
© 2003 European Renal Association-European Dialysis and Transplant Association
Patterns of CD4/CD8 T-cell ratio in dialysis effluents predict the long-term outcome of peritonitis in patients undergoing peritoneal dialysis
Departments of 1 Pediatrics and 5 Internal Medicine, Section of Nephrology, Taipei Veterans General Hospital, 3 Department of Pediatrics, Children Hospital, Changhua Christian Hospital, and 2 Institute of Clinical Medicine and 4 Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan, Republic of China
Background. The peritoneal immune compartment is a microenvironment with a particular T-cell repertoire and susceptible to local inflammation. To clarify the role of T lymphocytes in peritoneal immunity, the changes in T-cell subpopulations in peritoneal dialysis effluents (PDEs), and their influence on the response to the treatment of peritonitis and on its prognosis were studied in patients undergoing long-term, continuous ambulatory peritoneal dialysis (CAPD).
Methods. A cohort of 36 patients treated with CAPD and who had histories of peritonitis were divided into a group with rapid and a group with delayed response to antibiotics, and were followed for 3 years. CD4/CD8 T-cell ratios, T-cell cytokine mRNA expression patterns and transforming growth factor-ß1 (TGF-ß1) concentrations were examined in PDE during bouts of peritonitis. The change in 4 h D/P creatinine during the peritoneal equilibration test (PET) between year 0 and year 3 was expressed as 
D/P creatinine.
Results. The serial changes in T-cell subsets in PDE during peritonitis showed two patterns: (i) pattern 1, manifest as a progressive increase in the CD4/CD8 ratio, and associated with a rapid response to treatment; and (ii) pattern 2, manifest as a progressive decrease in the CD4/CD8 ratio, and associated with a delayed response to treatment. The major T-cell phenotypes in PDE during peritonitis were Th1-CD4+ and Tc2-CD8+, determined by cloning techniques, RT–PCR and double immunofluorescence staining. TGF-ß1 in the effluent was undetectable in pattern 1 after 7–8 days, but remained detectable at 2 weeks in pattern 2. Pattern 2 patients had a significantly greater decrease (D/P creatinine: -0.198±0.086) in solute transport than pattern 1 patients (D/P creatinine: -0.036±0.077, P<0.05).
Conclusions. These results suggest that a progressive decrease of the CD4/CD8 ratio in PDE correlates with a persistent expression of TGF-ß1, and plays a pathogenetic role in the evolution of peritonitis, PET deterioration and peritoneal fibrosis. Therefore, patterns of CD4/CD8 T-cell ratio in PDE may predict clinical outcomes of peritonitis in CAPD patients.
Keywords: CD4+ T cells; CD8+ T cells; peritoneal dialysis; peritonitis; TGF-ß1
Correspondence and offprint requests to: Ching-Yuang Lin, MD, PhD, Department of Pediatrics, Changhua Christian Hospital, 135 Nanhsiao St. Changhua, 550, Taiwan. Email: 100966{at}cch.org.tw