Association of serum immunoglobulin G level with peritonitis in patients undergoing peritoneal dialysis: An analytical study

Introduction: Peritonitis is one of the most common complications of peritoneal dialysis. On the other hand, reduced levels of immunoglobulins (Igs), mainly IgG, can increase the risk of infection in various pathologic conditions. Here, we aimed to determine the association of severity and frequency of peritonitis with serum IgG levels in peritoneal dialysis patients. Methods: 100 patients with chronic renal failure referred to Imam Reza Hospital, Tabriz, Iran, for peritoneal dialysis were included in the study. Serum IgG levels were measured in all of these patients at the beginning of the study and after six months of follow-up. In case of peritonitis, serum IgG levels were also measured, and samples were sent to Imam Reza Hospital laboratory for analysis. Results: 40 cases (40%) were women, and 60 cases (60%) were men with a mean age of 47 years. 24 cases (24.0%) had at least one episode of peritonitis during the study. Among those with peritonitis, 14 cases (60.9%) had at least one more peritonitis episode in the 6-month follow up. The mean serum IgG levels were 1079 mg/dl and 429 mg/dl at the beginning and after six months of follow up, respectively. The difference was shown to be statistically significant (P = 0.006). There was no correlation between serum IgG level reduction and peritonitis in these patients (P > 0.999). Conclusion: This study found reduced levels of serum IgG in patients undergoing peritoneal dialysis. However, it was not associated with increased risk of peritonitis in these patients.

Benefits of low dose immunoglobulin in the treatment of refractory CAPD peritonitis and longevity of technical survival on CAPD

In this study we investigated the long term results of intraperitoneal immunoglobulin (Ig) treatment in continuous ambulatory peritoneal dialyses (CAPD) patients with refractory or relapsing peritonitis. Sixteen CAPD patients (4 female, 12 male) with a mean age of 53 +/- 11 years (40-80), with a mean CAPD duration of 46.2 +/- 4.8 months (17-75) were included in the study. The patients included had a diagnosis of either refractory or relapsing peritonitis unresponsive to appropriate antibiotic therapy. 0.5 g of Ig was added to every exchange bag qid as an adjunctive therapy to the culture based antibiotherapy for 7 days. Intraperitoneal Ig treatment was found to be successful in treating peritonitis in all but one patient. Interestingly, following Ig treatment, long term peritonitis rate decreased significantly compared to the period before treatment (before: 2.2 +/- 0.6 episodes/patient/year vs. after: 0.6 +/- 0.17 episodes/patient/year; P = 0.019). The mean CAPD duration after Ig treatment was 30.5 +/- 5.4 (4-64) months. Out of 16 patients, one patient who was unresponsive, had his catheter removed and was switched to hemodialysis, and four patients with preexisting ultrafiltration failure or inadequate dialysis problems were transferred to hemodialysis after successful treatment of their peritonitis, one patient was transplanted and 10 patients continued on CAPD. We conclude that low dose Ig treatment may be beneficial in the treatment of refractory or relapsing CAPD peritonitis possibly through restoring impaired host defense within peritoneal cavity. This therapy, by preventing further peritonitis attacks, may prolong survival on CAPD.

Mannose binding lectin level and polymorphism in patients on long-term peritoneal dialysis

BACKGROUND

Infection is a leading cause of mortality and morbidity in patients with end-stage renal disease. The increased susceptibility to infection is probably secondary to the impaired immune defence in uraemia and other co-morbid factors such as diabetes mellitus. Peritonitis remains the most common and major complication in the treatment modality of peritoneal dialysis (PD) for uraemic patients. Mannose binding lectin (MBL) is a calcium dependent C-type lectin that acts as an important first line defence mechanism against infection by its capability to activate the complement system and enhance phagocytosis.

METHODS

We examined whether serum concentration of MBL and the point mutation of MBL may act as a risk factor in PD-related peritonitis. We studied four groups of dialysis patients: PD patients with two or more episodes of peritonitis, peritonitis-free PD patients, haemodialysis (HD) patients not previously on PD, and HD patients who were converted from PD due to technique failure following peritonitis-related abdominal adhesion. Results. Both homozygous and heterozygous patients had profoundly reduced serum level of MBL. The codon 54 point mutation rate amongst our dialysis patients was comparable with that of healthy subjects. Dialysis patients had a significantly lower serum level of MBL than healthy controls independent of the MBL gene mutation or the mode of dialysis treatment. Patients on PD with codon 54 point mutation were found to have a lower serum MBL level compared with HD patients with similar MBL gene mutation. However, we found no difference in the serum MBL level or frequency of codon 54 point mutation between four groups of dialysis patients.

CONCLUSIONS

Dialysis patients have lower MBL levels that may increase the susceptibility of infection. However, the existence of other risk factors such as connection technique, nasal bacterial carriers, bowel pathology and personal hygiene precludes the MBL level as the sole primary factor for peritonitis in patients on maintenance PD treatment.