Detection of IgM specific antibody using indirect immunofluorescent assay for diagnosis of acute leptospirosis.

Leptospirosis is a worldwide zoonosis, caused by Leptospira interrogans. At the earlier stage of the disease, the IgM immunoassays are expected to have more sensitivity than other immunoassays. Previous reports showed that the indirect immunofluorescent assay for detection of immunoglobulins (IFA-Igs) against Leptospira spp showed higher sensitive and specific than some genus specific tests. The authors determined an efficacy of the indirect immunofluorescent assay for detection of IgM specific leptospiral antibody (IFA-IgM). One hundred and eighty patients with acute febrile illness without localizing signs admitted to Hat Yai Hospital were studied. Using the cut-off value of > or = 1:400, the overall sensitivity, and overall specificity of the IFA-IgM were 89.2 per cent and 95.1 per cent, respectively. They were slightly greater than those of the conventional IFA-Igs (86.5% and 91.6%). The first sera obtained from patients including acute sera and single sera showed a low sensitivity (32.4%) but still higher than the IFA-Igs (29.7%). None of the patients with various diseases commonly confused with leptospirosis or healthy blood donors gave a titer greater than 1:200. In conclusion, the IFA-IgM has the same protocol as the IFA-Igs but the sensitivity and specificity is slightly greater than the IFA-Igs. This is another alternative test for the diagnosis of acute leptospirosis.

Serum insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) in healthy Thai children and adolescents: relation to age, sex, and stage of puberty.

The authors studied the serum concentrations of insulin-like growth factor-1 (IGF-1) and IGF-binding protein-3 (IGFBP-3) in 260 healthy children and adolescents (115 males, 145 females) aged 5-20 years. The subjects were divided into 12 groups according to age and sex. The serum IGF-1 and IGFBP-3 concentrations increased with age and peaked at age 13-15 years in males, and 11-13 years in females. After the peak concentration, IGF-1 and IGFBP-3 levels declined significantly in males, but were still high in females. Comparing between sexes, the concentrations of IGF-1 and IGFBP-3 were greater in females than males in all age groups. However, when subjects were divided according to the stage of puberty, the different concentrations between sexes were not significant, except for children within Tanner stage V where concentrations of IGF-1 and IGFBP-3 were significantly greater in females than males. Multiple regression analysis demonstrated the age, sex, and stage of puberty-dependent of IGF-1 concentration, and only the age and sex-dependent of IGFBP-3 concentration.