RESUMO
Prevalence and levels of systemic and milk antibodies to G. lamblia in the different social classes of the population were studied using the IFAT and nor-partigen immunoglobulin plates. Blood and milk samples were collected simultaneously from lactating women in urban (Cairo) and rural (Benha) areas. Serum IgG was present in 90% of rural low standard mothers, 58% of urban moderate standard mothers, and 25% or urban high standard mothers (P less than 0.01, P less than 0.001 and P less than 0.01). Antilog of mean of antibody titers was significantly higher in the low standard rural mothers than in the urban moderate and high standard ones. Specific secretory IgA antibody in milk was found in 71% of rural low standard mothers, 31% of urban moderate standard mothers, and 16.6% of urban high standard mothers (P less than 0.001, P less than 0.01 and P greater than 0.05). The antilog of mean S-IgA titers was also higher in the low standard rural mothers. The titer levels of S-IgA in the three classes did not show any correlation with the quantitative levels of total IgA in milk, while specific IgG showed a positive correlation with the total serum IgG in the low standard rural mothers only (P less than 0.05). This study documented the widely different antibody response to G. lamblia in individuals living in different social classes.
PIP: Total IgG and secretory IgA antibodies, and specific IgG and S-IgA antibodies against Giardia lamblia were assayed in serum and milk respectively from 118 Egyptian mothers. The women were selected from 3 social classes: 24 of upper class from Cleopatra Hospital, Cairo, 52 of moderate social class from Ain Shams Maternity Hospital, Cairo, and 42 of low social class from Maternal and Infant Welfare Centers in rural Benha. Total IgG and S-IgA antibodies were assayed with the nor-partigen method, and specific G. lamblia antibodies with an indirect fluorescent antibody method. IgG antibodies in serum specific for G. lamblia were present in 62.7% of the total group: 90% from the low, 58% of the moderate, and 25% of the high social groups, all significantly different. Mean total IgG levels were 15.42, 19.81 and 33.5 g/L in the 3 groups (n.s.). Secretory IgA antibodies specific for G. lamblia occurred in 42.3% of the total milk samples: in 71% of the low, 31% of the moderate, and 16.6% of the high social class groups (low group significantly different from moderate and high groups). The mean total IgA level in the milk samples did not differ from normal. While the specific IgG titers were positively correlated with the total IgG content in serum, milk total S-IgA levels were not significantly correlated with specific anti-Giardia lamblia S-IgA titers. These results were similar to those reported from other contexts, and support the advice that women breastfeed their infants through age 2 to confer immunity against Giardia parasites.
