OBJECTIVE: To evaluate the immune response to chickenpox natural infection in pediatric patients with chronic renal insufficiency. METHODS: This cross-sectional study enrolled 83 patients between 18 months and 18 years old, with glomerular filtration rate below 70mL/min/1.73m², during the years 2000 and 2001, who did not received specific immunization according to official documentation. Three patients (3/83) had been previously vaccinated by non-governmental agencies and were excluded. Varicella antibodies were evaluated by Enzyme-Linked Immuno Sorbent Assay and antibody titers above 100mUA/mL were considered protective. RESULTS: The median age was 11 years old, 66% were male, 60% lived in the city of São Paulo, with an average glomerular filtration rate of 33.6mL/min/1.73m². Clinical diagnosis of chickenpox was done by pediatricians in 39 patients and four of these 39 were seronegative for varicella. Susceptibility to chickenpox was found in 21/80 (26%) patients and the relative prevalence of susceptibility to the disease was 7.93 (95%CI=3.29-19.12) higher in patients under six years of age. CONCLUSIONS: Susceptibility to varicella infection decreased with age. Patients younger than six years were eight times more susceptible than older patients and twice more susceptible compared to the Brazilian pediatric population of the same age group.
vaccination; renal insufficiency, chronic; child; adolescent; chickenpox
