IgG and IgG subclasses deficiency in children undergoing continuous ambulatory peritoneal dialysis and its provocative factors

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.

Peritoneal dialysis in infants: the experience of the Italian Registry of Paediatric Chronic Dialysis

BACKGROUND

Although chronic peritoneal dialysis (CPD) is considered the replacement therapy of choice for infants with end-stage renal failure, many questions persist about treatment risks and outcomes.

METHODS

We present data on 84 infants who started CPD at <1 year of age; these patients represent 12% of the total population of the Italian Registry of Paediatric Chronic Dialysis. We analysed patient records from all children consecutively treated with CPD between 1995 and 2007 in Italy. Growth data analysis was performed only in infants with complete auxological parameters at 0, 6 and 12 months of follow-up.

RESULTS

Median age at the start of CPD was 6.9 months, weight was 6.1 kg and length 63.6 cm. In one-half of the study population diagnosis leading to renal failure was congenital nephrouropathy. Twenty-eight per cent of the children had at least one pre-existing comorbidity. The mean height standard deviation score was -1.65 at the start of CPD, -1.82 after 12 months and -1.53 after 24 months. Catch-up growth was documented in 50% of patients during dialysis. A positive correlation was observed between longitudinal growth and both exchange volume (R(2) = 0.36) and dialysis session length (R(2) = 0.35), while a negative association was found with the number of peritonitis cases (P = 0.003). Peritonitis incidence was 1:20.7 episode:CPD-months (1:28.3 in the older children from the same registry) and was significantly higher in children with oligoanuria (1:15.5 episode:CPD-months) compared to infants with residual renal function (1:37.4 episode:CPD-months). Catheter survival rate was 70% at 12 months and 51% at 24 months. Catheter-related complications were similar in infants and older children (1:20.5 versus 1:19.8 episode:CPD-months), while clinical complications were more frequent in children under 1 year of age (1:18.3 versus 1:25.2 episode:CPD-months; P < 0.05). During the follow-up period, 33 patients were transplanted (39.3%), 18 were shifted to haemodialysis (21.4%) and 8 died (9.5%). The mortality rate was 4-fold greater than in older children (2.3%).

CONCLUSIONS

Our data confirm that infants on CPD represent a high-risk group; however, our experience demonstrated that growth was acceptable and a large portion was successfully transplanted. Increased efforts should be aimed at optimizing dialysis efficiency and preventing peritonitis. The higher mortality rate in infants was largely caused by comorbidities.

Hypokalaemia: an independent risk factor of Enterobacteriaceae peritonitis in CAPD patients

BACKGROUND

Hypokalaemia is a relatively common complication in uraemic patients undergoing continuous ambulatory peritoneal dialysis (CAPD). The hazards of hypokalaemia are multiple and have been correlated with patient morbidity and mortality. Whether it is associated with increased risk of peritonitis remains to be addressed.

METHODS

We retrospectively analysed our CAPD patients who had complicating peritonitis in a 2-year period. The influence of hypokalaemia on the clinical features of peritonitis was assessed. From September 2003 to August 2005, 140 unselected patients undergoing CAPD treatment and followed up in our hospital were recruited for the study. Hypokalaemia was defined as a serum potassium level <3.5 mmol/l. The impact of hypokalaemia on several clinical parameters, including the nutrition status, dialysis adequacy, occurrence of peritonitis and the etiologic pathogens, was analysed.

RESULTS

During the study period, 462 determinations (23.6%) were below quantity <mmol/l. The overall peritonitis rate was 30.6 patient-month per episode (total 64 episodes). The prevalence of peritonitis was significantly higher in patients with hypokalaemia (6.9%) compared to those without hypokalaemia (2.1%, P < 0.001). Hypokalaemia was also associated with lower serum albumin (P < 0.001), serum phosphate (P < 0.001), total serum cholesterol (P = 0.049) and normalized protein nitrogen appearance (P < 0.001). There was no correlation between serum potassium level and daily PD exchange volume, total Kt/V, urine volume or daily ultrafiltration volume. The peritoneal equilibration test was not significantly different between patients with and without hypokalaemia. When the aetiologic organisms of peritonitis were grouped according to their usual site of colonization, Enterobacteriaceae appeared to be much more prevalent than epidermal microorganisms (53.1% versus 18.8%, P = 0.004) in the hypokalaemia group. However, this was not the case in patients with normal serum potassium.

CONCLUSION

CAPD patients with hypokalaemia are associated with a higher prevalence of peritonitis and poor nutritional status. Enterobacteriaceae were the predominant organisms causing peritonitis in the group with hypokalaemia. This unique and novel finding implies the translocation of these organisms from intestinal mucosa into the peritoneal cavity. A pathogenic mechanism linking malnutrition and hypokalaemia is also proposed.