Immune status of children on continuous ambulatory peritoneal dialysis

Characteristics of Peripheral and Peritoneal White Blood Cells in Children with Chronic Renal Failure, Dialyzed or Not

Objective

To explore further the mechanisms leading to immune deficiency in chronic renal failure and the role of dialysis treatment in these mechanisms.

Design

Cross-sectional and longitudinal analysis.

Patients

We studied 39 children treated with peritoneal dialysis (PD), 23 children treated with hemodialysis (HD), 33 children not yet dialyzed [chronic renal failure (CRF)], and 27 healthy children. Peritoneal cells were also obtained from PD children for analysis.

Methods

White blood cells (WBCs) were isolated from blood and peritoneal dialysis effluent by centrifugation. The number of CD2+, CD4+, and CD8+T cells, B cells, and natural killer cells were measured by flow cytometry.

Results

The total peripheral blood lymphocyte count was lower in PD children (2.6 x 109/L), HD children (2.1 x 109/L), and CRF children (2.0 x 109/L) compared with healthy children (3.1 x 109/L, p < 0.05). The B lymphocyte count was also lower in PD children (0.34x109/L), HD children (0.22 x 109/L), and CRF children (0.33 x 109/L) compared with healthy children (0.52 x 109/L, p < 0.01). Numbers of CD4+T cells were not different, but numbers of CD8+T cells were lower in PD children (0.56 x 109/L), HD children (0.63 x 109/L), and CRF children (0.53 x 109/L) compared with healthy children (0.77 x 109/L, p < 0.05). The count of natural killer cells was lower in PD children (0.21 x 109/L), HD children (0.17 x 109/L), and CRF children (0.18 x 109/L) compared with healthy children (0.50 x 109/L, p < 0.0001). The CD4/CD8 ratio of lymphocytes in peritoneal effluent was 0.8 versus 1.9 in peripheral blood ( p < 0.001). The CD2/CD19 ratio was not different. The cell subsets remained stable during the first year of PD treatment. The CD2/CD19 ratio in peritoneal effluent was higher in children with a peritonitis incidence ≥ 1 per year.

Conclusions

The reduced numbers of B lymphocytes, CD8+T cells, and natural killer cells found in CRF children, dialyzed or not, may favor the frequent occurrence of infections.

Responses in children to measles vaccination associated with perirenal transplantation

BACKGROUND

Measles infection can be fatal in pediatric patients with chronic renal failure or in patients who have undergone renal transplantation, both of whom are in the immunosuppressed state. The efficacy of single, live measles vaccination in preventing infection was examined.

METHODS

Of 156 children with renal failure who underwent renal transplantation, the changes in antibody titer were investigated before and after renal transplantation in 125 children whose measles antibody titer could be examined, together with disease and vaccination histories. Live measles vaccine was administered to 42 children with negative antibody titer. The antibody seroconversion rate was then investigated in these children, along with rate of antibody maintenance and degree of antibody titer elevation.

RESULTS

Seroconversion rate was 97.6%. Antibody titers measured on HI and EIA were 72 +/- 118 fold (HI) and 36.9 +/- 31.3 (EIA), respectively. The geometric mean of the increase in antibody titer 6 months after vaccination was 15. No side-effects of vaccination were observed in any of the children.

CONCLUSIONS

Live measles vaccination of children with chronic renal failure is effective and safe, because the seroconversion rate, rate of antibody titer maintenance and degree of antibody titer elevation in children with chronic renal failure were all equivalent to those of healthy children.

Evaluation of antibody response to the heptavalent pneumococcal conjugate vaccine in pediatric chronic kidney disease

Pneumococcal vaccination has been recommended for immunocompromised children, including patients with chronic kidney disease. We determined pneumococcal immunoglobulin (Ig)G antibodies to serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F before and after 48 pediatric patients with chronic renal failure were administered heptavalent conjugated pneumococcal vaccine. The patients were between 1 and 9 years of age and were separated into a conservative treatment group (Group 1) and a dialysis group (Group 2). The antibody response to the vaccinal serotypes was evaluated by measuring antibody concentrations before the first dose and 60 days after the second one. Pre-vaccinal IgG concentrations > or = 0.35 microg/ml were detected for all serotypes in at least 50% of the patients in both groups. Patients from both groups showed a statistically indistinguishable behavior in terms of the medians of post-vaccination IgG levels. An "adequate" vaccine response was defined as a post-immunization level of specific pneumococcal serotype antibody > or = 0.35 microg/ml, based on the World Health Organization's (WHO) protective antibody concentration definition for pneumococcal conjugate vaccines, or on a fourfold increase over baseline for at least five of the seven antigens of the vaccine. An "adequate" vaccinal response was obtained in 100% of the patients of both groups using WHO's definition, or in 45.8% of Group 1 patients and 37.5% of Group 2 patients when the criterion was a fourfold antibody increase over baseline antibody concentrations.

Immunization in children with chronic renal failure: a practical approach

The prevention of systemic viral and bacterial infections by effective vaccination represents an essential task of pediatric nephrologists caring for children with chronic renal failure (CRF) undergoing renal transplantation (RTPL) with life-long immunosuppression. This review addresses three issues: risk of vaccine-preventable diseases, safety, immunogenicity, and clinical efficacy of available vaccines, and implementation of immunization guidelines. Infections (including vaccine-preventable infections) represent the leading cause of morbidity and mortality in children on dialysis and after RTPL. Vaccination in children with CRF and after RTPL is safe and does not cause reactivation of an immune-related renal disease or rejection after RTPL. Children with CRF generally produce protective serum antibodies to primary vaccinations with killed or component vaccines and live virus vaccines; some children on dialysis and after RTPL may not respond optimally, requiring repeated vaccination. Proof of vaccine efficacy is absence of disease, which can only be confirmed in large cohort studies. A few observational studies provide evidence that vaccination has contributed significantly, at least in the western hemisphere, to the low prevalence of vaccine-preventable diseases among children with CRF. Close cooperation between the local pediatrician/practitioner and the pediatric nephrologist is essential for successful implementation of the vaccination schedule.

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

BACKGROUND

Low levels of serum IgG or IgG subclasses may be responsible for the defective peritoneal defense and for peritonitis attacks in continuous ambulatory peritoneal dialysis (CAPD) children. Malnutrition, peritoneal loss or frequent peritonitis may lead to IgG or IgG subclasses deficiency.

METHODS

Levels of IgG subclasses were determined in 12 children undergoing CAPD treatment. Radial immunodiffusion technique was used for determination. Patients were aged from 6 to 16 years (mean age 12.3 years) and had been on CAPD for 11-26 months (mean duration 19.4 months). We evaluated whether IgG and IgG subclasses deficiency are related to malnutrition, the peritonitis rate and the duration of CAPD using the SPSS program.

RESULTS

Serum total IgG levels were found to be low in eight out of 12 patients. Eight patients showed low levels of IgG1, four patients IgG2, one patient IgG3 and three patients IgG4. Total IgG values were found to be positively correlated to malnutrition status, peritonitis rate and duration of CAPD. The IgG2 values were found to be related to the duration of CAPD. The IgG4 values were found to be correlated to the peritonitis rates.

CONCLUSIONS

The IgG and IgG subclasses deficiency may develop in children while on CAPD treatment. Periodical determinations of either serum IgG or the subclasses may be useful in the follow-up of these patients.

Immunologic defects and vaccination in patients with chronic renal failure

Patients with chronic renal failure suffer from defective host defenses which are directly the result of the renal impairment, in addition to those dependent on the primary illness leading to the renal failure. The mechanisms underlying the defective responses in phagocytic cells, lymphocytes and antigen processing are likely due to either failure to adequately eliminate suppressive compounds by the defective kidneys or to improper metabolic processing of the factors by the damaged renal parynchema. That some of the defects are reversed by transplantation and not dialysis suggests that renal parenchymal metabolic activities may be involved, although it is also possible that functioning glomerular cells are capable of filtering substances that membranes are not currently capable of eliminating. The current strategy for dealing with the immunodeficiency appears to be totally based on developing means to circumvent the defective function. The other approach, correction of the impaired function, cannot be even considered until the mechanisms underlying the defective function of the cells involved in defenses are better delineated. It seems possible that one or a few compounds are pivotal in altering the function of all the affected cell lines, since, with only a small amount of effort, it is possible to relate the dysfunction to abnormal cell membrane functions in phagocytic cells, dendritic cells and lymphocytes. Until the biochemical basis of the dysfunction of all the cell types affected are better defined, such exercises cannot be translated into better management of patients with chronic renal failure. Proper function of host defenses requires that appropriate cells can properly respond to threats to host viability. For the cells of the immune system (phagocytes and lymphocytes) this means that their response to regulatory molecules be appropriate, that their mobility be normal, that their adherence to substrates be preserved, and that they can generate the appropriate response to the challenge. For neutrophils, for example, it is necessary that they recognize and mobilize appropriately to chemotactic stimuli, that they be able to adhere to and migrate through endothelial lining, that their phagocytic activity be sufficient, and that they can kill and degrade endocytosed particles and generate appropriate secretions. Similar lists of requirements for good function can be generated for any cell type in the immune defense system. Uremia, as well as currently available treatments for uremia, directly or indirectly alters the function of all phases of appropriate immune cell function. Defective host responses in uremia have been recognized for decades and there has been considerable effort in the past decade to better define the extent and mechanisms of impaired defenses. Despite the multitude of major defects in humoral, cellular, and inflammatory processes, uremic patients who are cared for today, although they remain at higher risk of serious infectious complications, can and do maintain a good quality of life, with most remaining free of major infections for years and decades.

Management of end-stage renal disease in children

OBJECTIVE

To review the medical literature on management of end-stage renal disease (ESRD) and its complications in the pediatric patient.

DATA SOURCES AND STUDY SELECTION

MEDLINE searches (1970-1997) of the English-language literature. Clinical trials and reviews of drug therapy management were included, and bibliographies were reviewed for relevant articles.

DATA SYNTHESIS

Principles of renal replacement therapy in children have been expanded to include maintenance of fluid and electrolyte balance and to manage the complications of ESRD in children. Types of renal replacement and their complications are reviewed. Complications of ESRD are reviewed with emphasis on drug therapy management of anemia of chronic renal failure, growth retardation, and hypertension. A discussion of the use of vitamins and supplements to maintain bone and mineral homeostasis is provided, and specific recommendations for vaccination of children with ESRD are given.

CONCLUSIONS

Children with end-stage renal failure present a unique challenge to the pharmacist. Renal replacement therapy for children with ESRD involves some form of dialysis and an intensive medication regimen. Complications must be treated with appropriate drug therapy. Drug therapy must be monitored closely for dosage adjustment, clinical response, drug interactions, and toxicity. Patients and families must receive continuous education and follow-up to encourage compliance. The pharmacist must work closely with the healthcare team to optimize drug therapy and improve patient education and compliance.

Use of licensed vaccines for active immunization of the immunocompromised host

The latter part of the 20th century has witnessed an unprecedented rise in the number of individuals with impaired immunity. This is primarily attributable to the increased development and use of antineoplastic therapy for malignancies, organ and bone marrow transplantation, and the AIDS epidemic. Individuals with impaired immunity are often at increased risk for infections, and they can experience more severe and complicated courses of infection. The lack of therapy for a variety of viruses and the rise in antimicrobial resistance of many pathogens have focused attention on vaccination to prevent infectious diseases. The efficacy of most licensed vaccines has been established in immunocompetent hosts. However, there is also considerable experience with most vaccines in those with impaired immunity. We reviewed the use of licensed live, inactivated, and polysaccharide vaccines in this group, and several themes emerged: (i) most vaccines are less immunogenic in those with impaired immunity than in normal individuals; (ii) live vaccines are generally contraindicated in this group; and (iii) the efficacy of many commonly used vaccines has not been established in people with impaired immunity. This review suggests that for most vaccines there are little or no efficacy data in those with impaired immunity but their use in this patient group is generally safe.

Host defences in continuous ambulatory peritoneal dialysis and the genesis of peritonitis

Continuous ambulatory peritoneal dialysis (CAPD) has come to be extensively used for the treatment of end-stage renal failure in children, and especially infants, such that now more than half of children on dialysis worldwide receive treatment by this means. Peritonitis, however, is commoner in children than in adults receiving treatment, and is a major source of morbidity and treatment failure in children started on CAPD. Only recently has the immunology of the normal peritoneum been studied extensively, with the need to assess the impact of the installation of large volumes of fluid into the peritoneal sac during dialysis. The main phagocytic defences of the peritoneum depend upon a unique set of macrophages which are present free in the peritoneal fluid but also in the submesothelium and in perivascular collections together with B lymphocytes in the submesothelial area. Both the number of macrophages per unit volume and the concentration of opsonic proteins, such as IgG, complement and fibronectin, are reduced to between only 1% and 5% when dialysis fluid is continuously present in the peritoneal sac. In addition, the fluids used for CAPD are toxic to both macrophages and to mesothelial cells. Thus minor degrees of contamination frequently lead to peritonitis and in addition the majority of patients have catheters inserted in their peritoneum which become colonised with organisms capable of producing exopolysaccharide (slime), which promotes adhesion of the organism to the plastic and protects them against phagocytic attack and the penetration of antibiotics. Thus the peritoneum is in a state of continual inflammation, as well as being a markedly more vulnerable site than the normal peritoneum to the entry of organisms. Whether clinical peritonitis appears in this state of chronic contamination probably depends on perturbation in the balance between host defences and the organism. Whilst Staphylococcus epidermidis is the commonest cause of peritonitis, Staphylococcus aureus and Gram-negative organisms are much more serious and more frequently lead either to temporary catheter removal or discontinuation of dialysis altogether. This review describes the peritoneal defences in relation to the genesis of peritonitis.

Comparison of asymptomatic and symptomatic childhood glomerulonephritis progressing to renal failure: a report of Kyushu Pediatric Nephrology Study Group

We evaluated the clinicopathological features and the outcome of 33 children with primary glomerulonephritis (GN) as the cause of renal failure; 17 had asymptomatic (ASP) haematuria and/or proteinuria and the remaining 16 had symptoms suggestive of GN. The renal histology in the ASP group indicated IgA GN in 6 children, focal segmental glomerular sclerosis (FSGS) in 4, diffuse proliferative GN (DPGN) in 3, membranous GN (MGN) in 1, membranoproliferative GN (MPGN) in 1 and diffuse sclerosing GN in 2. In the symptomatic (SYP) group, FSGS was evident in 9 children, DPGN in 3, MGN in 2, IgA GN in 1 and MPGN in 1. There was no difference in the histological severity between the two groups. Fourteen children in the SYP group had nephrotic syndrome (NS) and/or hypertension at their initial visits. Only 4 children in the ASP group showed NS or hypertension during the period of follow-up. Eleven children in the ASP group and all in the SYP group were treated with immunosuppressive and/or antihypertensive drugs, but these did not improve the prognosis of the ASP children compared with those in the SYP group. There was no significant difference in the mean duration between the onset of the disease and the start of dialysis in these two groups. In conclusion, it is questionable whether the urinary mass screening programme in Japan will alter the outcome of children with GN.

Defective antibody response to Hemophilus influenzae type b immunization in children receiving peritoneal dialysis

Pediatric end-stage renal disease patients, maintained on chronic peritoneal dialysis (CPD), may have a variety of immunological abnormalities, including hypogammaglobulinemia and poor responses to vaccines. We measured antibody levels to Hemophilus influenzae type b (Hib) in 24 CPD patients. Eight children received primary Hib immunization while undergoing CPD. Of these, 1 of 8 (12%) lacked protective levels of antibody. In another child, who had an initial protective response, antibody levels were undetectable 12 months after immunization. Sixteen of the patients had not been immunized with Hib vaccine because they were more than 5 years old when the vaccine was licensed. In this group, 5 of 16 (31%) lacked protective levels of anti-Hib antibody. Of those available for follow-up, 3 responded normally to Hib vaccine. It is not sufficient to provide childhood immunizations to CPD patients with the assumption that those immunizations will lead to long-lived immunity. Antibody levels should be measured within a month of immunization and at regular intervals thereafter to document immunity.

Hypogammaglobulinemia and fatal sepsis in an infant maintained on peritoneal dialysis

Chronic peritoneal dialysis (CPD) is a common form of renal replacement therapy in children. Recent studies suggest that immunological abnormalities, in particular hypogammaglobulinemia, may develop in children and infants on peritoneal dialysis. We report an infant maintained on CPD who died of gram-negative sepsis. At post-mortem examination, he was noted to have severe panhypogammaglobulinemia.