Enuresis--an unattended comorbidity of childhood obesity.

OBJECTIVE: Obstructive sleep apnea (OSA), attention deficit/hyperactivity disorder (ADHD), type 2 diabetes mellitus and psychopathological problems co-occur at increased rates among both obese and enuretic children. We hypothesized that the prevalence of enuresis will be increased in obese children and adolescents. DESIGN: A cross-sectional study. SUBJECTS: 281 children and adolescents aged 7-18 years, who completed a questionnaire regarding enuresis, medical conditions and sociodemographic parameters; 158 were normal weight, 37 overweight (85thBMI (body mass index)<95th percentiles) and 86 obese (BMI95th percentile). MAIN OUTCOME MEASURE(S): Occurrence of enuresis among obese children and adolescents. RESULTS: Enuresis was reported in 14 (8.8%) normal weight, 6 (16%) overweight and 26 (30%) obese youth. Odds ratio (OR)=6.5, 95% confidence interval (CI)=2.67-15.78 for enuresis among obese compared with normal weight (P<0.0001). Each increment of one BMI-Z score unit was associated with an increased risk of enuresis, OR of 2.14, 95% CI (1.46-3.12), P=0.00008. Male gender (OR 2.84, 95% CI (1.10-5.58), P=0.028), first-degree relative with current/past enuresis (OR 4.24, 95% CI (1.62-11.08), P=0.003), voiding dysfunction symptoms (OR 3.067, 95% CI (1.05-9.00), P=0.041) and ADHD (OR 2.31, 95% CI (0.99-5.34), P=0.051) increased the risk of enuresis. OSA-related symptoms, academic achievements in school, sharing a bedroom, family size relative to number of rooms in home, parental education, family status and religious observance were not found to increase the risk for enuresis. CONCLUSIONS: Obese children are at increased risk for enuresis. Enuresis should be clarified during the primary workup of every obese child and adolescent.

Absence of anti-idiotypic antibodies in IVIG preparations to autoantibodies of rare autoimmune diseases.

Intravenous immunoglobulins (IVIG) were found to contain anti-idiotypic antibodies against autoantibodies of various autoimmune diseases. We examined commercial IVIG preparations, from three different manufactures, for the presence of autoantibodies and anti-idiotypic antibodies of two rare autoimmune diseases--primary biliary cirrhosis [anti-pyruvate dehydrogenase (PDH) antibodies] and Goodpasture's syndrome (anti-NC1 antibodies). We used ELISA studies as well as immunoblotting and anti-PDH enzyme activity for the detection of anti-PDH antibodies. ELISA and immunofluorescence studies were used for the detection of anti-NC1 antibodies. The presence of anti-idiotypic activity against anti-PDH fragments on Sepharose-bound IVIG [F(ab)2]. Anti-anti-NC1 activity was evaluated employing inhibition ELISA and immunofluorescence studies. The commercial IVIG preparations that were examined did not contain anti-PDH or anti-NC1 antibodies nor anti-idiotypic activity against these autoantibodies. We conclude that commercial IVIG may lack anti-idiotypic activity against rare autoantibodies.

The significance of sweat Cl/Na ratio in patients with borderline sweat test.

Recently a few cystic fibrosis (CF) patients with borderline or normal sweat tests have been reported. These patients present a diagnostic challenge. We aimed to study the sweat Cl/Na ratio in cystic fibrosis patients and to assess whether this ratio could be used as a diagnostic criteria. The mean sweat Cl/Na ratio of 3 groups was compared: Group A: 71 CF patients carrying 2 mutations known to be associated with severe disease presentation (delta F508, W1282X, G542X, N1303K, 1717-1G --> A). Group B: 10 compound heterozygous patients who carry one mutation associated with mild clinical disease (3849 + 10 kb --> T). Group C: 142 normal subjects. Sweat chloride levels higher than those of sodium were found in 96% of patients in Group A as compared to 3% of patients in Group C. In Group B 40% of the patients had sweat chloride levels higher than or equal to sodium levels. The mean Cl/Na ratio of Group A (1.2 +/- 0.1) differed significantly from that of Group B (0.94 +/- 0.1) and both groups had significant higher mean Cl/Na ratio compared to Group C (0.7 +/- 0.4) (P < 0.001). Thus in individuals with a borderline sweat test and a Cl/Na ratio > or = 1 the diagnosis of CF should be considered. However, a Cl/Na ratio < 1 does not exclude CF, since patients carrying mild mutations may have sweat sodium levels higher than those of chloride. Our findings suggest that the sweat Cl/Na ratio in CF is genetically determined and it may be of help in establishing the diagnosis of CF in patients with a borderline sweat test.

Induction of Goodpasture antibodies to noncollagenous domain (NC1) of type IV collagen in mice by idiotypic manipulation.

The characteristic pathogenic autoantibodies in Goodpasture's syndrome (GPS) are directed to the noncollagenous domain (NC1) of basement membrane type IV collagen. To examine whether immunization with anti-NC1 antibodies could lead to GPS-like pathology, naive BALB/c mice were immunized intradermally with a mouse IgG anti-NC1 monoclonal antibody or IgG serum fraction derived from patients with GPS. Mice immunized with normal mouse or human IgG and nonimmunized mice served as controls. Anti-NC1 antibodies of IgG isotype were detected in the sera of mice injected with anti-NC1 antibodies, but not in the sera of control mice. The presence of circulating anti-NC1 antibodies coincided in some of the mice erythrocyturia or proteinuria and pathological changes in the kidneys. No pathologic alterations were seen in the control mice. The results show that specific idiotypic manipulation can induce anti-NC1 antibodies and pathological changes resembling human GPS.