Chronic diarrhea and abnormal serum immunoglobulin levels: a case report.

A 15-year-old Thai boy with multiple episodes of chronic diarrhea caused by giardiasis with hypogammaglobulin M and IgG4 subclass deficiency (but normal antibody response to rabies vaccine) is reported. Immune status follow-up is necessary for a definite diagnosis and proper management.

IgA deficiency: clinical correlates with IgG subclass and mannan-binding lectin deficiencies

OBJECTIVE: To characterize an IgA deficient population in terms of the incidence of IgG subclass and mannose-binding lectin (MBL) deficiencies and the type and severity of infections and other associated disorders. BACKGROUND: Selective IgA deficiency is probably the commonest of the primary immunodeficiency disorders and although it may lead to an increased risk for respiratory and gastrointestinal infections and associated to various autoimmune diseases, it may also be asymptomatic. Several studies have suggested the need of a concomitant defect in order for manifestation of its symptoms. METHODS: A total of 27 patients fulfilling the diagnostic criteria of selective IgA deficiency were evaluated for IgG subclass and MBL deficiencies after a thorough medical history, physical examination and pertinent evaluation for concomitant medical conditions. RESULTS: The overall incidence of IgG subclass deficiency found in the IgA deficient group was 18.5. MBL deficiency was found to be 3.7. These frequencies may have been influenced by the age group evaluated and the size of the population studied. Severe infections were more common in patients with combined deficiencies, either IgA and any of the IgG subclasses or IgA and MBL deficiency. Atopy was widely represented in the patients studied. CONCLUSIONS: The observed relationship between combined deficiencies Ig A, IgG subclasses and MBL and the increased representation of severe infections needs to be corroborated in a larger sample of patients with an inclusion of pediatric patients.

IgG subclasses in wheezing infants.

The wheezing infant is a common but difficult patient to approach diagnostically. The prevalence of IgG subclass antibody deficiency in wheezing infants is still controversial. We studied serum concentration of IgG subclasses in 38 wheezing infants (aged 6-24 months who had not received systemic steroids before investigation) and in 30 healthy age matched control (aged 6-24 months). The prevalence of one or more IgG subclass deficiency was 31.6% in wheezing infants and 26.7% in controls. There was no significant difference in prevalence of IgG subclass deficiency between patients and controls (p > 0.05). The mean concentration of IgG subclasses in patients were compared with controls. There was no significant difference in mean serum concentration of IgG1, G2 and G3 subclasses. But there was a trend towards higher concentrations of IgG4 in wheezing infants and this difference for IgG4 was significant (p < 0.01). However, IgG subclass deficiency was found in 25% and 36.4% of wheezing infants who had experienced from two to four and five or more wheezing episodes in two years, respectively (p > 0.05). These findings suggest that wheezing in infancy is not associated with IgG subclass deficiency and in wheezing infants low IgG subclass levels do not increase the frequency of wheezing.