Human herpes virus 6 antibodies in beta-thalassemia/hemoglobin E pediatric patients.

Human herpesvirus 6 (HHV-6) is a viral pathogen that causes exanthem subitum in children. It has also been identified as the cause of life-threatening illness in immunocompromised pediatric patients and transplant recipients. We undertook a serological study of HHV-6 IgM and IgG antibody among 29 children (12 females and 17 males) with beta-thalassemia/HbE disease. The rate of infection was 86.2%; the rates of early recent infection (IgM positive only), recent infection (both IgM and IgG positive) and past infection (IgG positive only) were 13.8%, 41.4% and 31.0%, respectively. The geometric means of the IgM and IgG titers of the splenectomy group (9 cases) were 10.15 units and 11.18 units, respectively. The geometric means of the IgM and IgG titers of the non-splenectomy group (20 cases) were 10.10 units and 12.84 units, respectively. According to this study, the prevalence of HHV6 infection among pediatric patients with beta-thalassemia/HbE is very high; morever, the significantly higher titer among these patients may imply a high risk for further possible bone marrow transplantation. Increased awareness of HHV-6 infection among this population is necessary.

Methodology evaluation of a new immunoturbidimetric method for measuring serum soluble transferrin receptor.

The value of soluble transferrin receptor (sTfR) detected in serum is closely related to erythroid TfR turnover rate. An increased erythropoietic activity causes an increase in the sTfR level. Therefore, it is a useful test for monitoring the erythropoiesis. In this study, a new immunoturbidimetric method for automated measurement of sTfR was evaluated for its performance characteristics. Imprecision studies on patients' sera with 1.01 mg/l and 2.94 mg/l concentrations yielded within-run CVs of 1.16% and 1.27%. Accuracy analysis of the test by using the low and high control kit sera with 1.45 mg/l and 5.41 mg/l concentrations were 89.06% and 95.41%, respectively. The evaluation was also performed in 60 individual pediatric subjects, 30 beta-thalassemia/HbE and 30 control pediatric subjects. There is a statistically significant difference of sTfR between both groups (p < 0.0005, 95% Cl = 9.457-14.124). Ninety-five percent of matched pediatric subjects had sTfR level < or = 2.670 mg/l and 93.33% of patients diagnosed beta-thalassemia/HbE had values > 2.670 mg/l. In conclusion, this immunoturbidimeteric test yields good laboratory performance characteristics in terms of precision and accuracy.