RESUMO
AIMS: We aimed to determine the normal immunoglobulin values of Turkish new-borns by studying IgG, IgA, IgM, and IgG subgroups (IgG1, IgG2, IgG3, and IgG4) from term, healthy neonates born in the Sakarya province of Turkey. SUBJECTS AND METHODS: In our study, IgA, IgM, IgG, and IgG subgroup levels were measured nephelometrically in 54 new-borns (15-21-day-old). They were born between 39 and 41 weeks of gestation by problem-free delivery and with Apgar scores >8 at 1 and 5 minutes. The enrolled neonates were singletons and were free of congenital diseases/anomalies, history of perinatal infection, and with no known history of transfusion or chronic disease in the mother. The study findings were also evaluated in terms of differences based on delivery mode, feeding type, gender, and demographic characteristics. RESULTS: This study enrolled 54 new-borns, 42 (77.8%) of whom were born by cesarean section and 12 (22.2%) by spontaneous vaginal delivery. Of the new-borns, 41 (75.9%) were only breastfed, and 13 (24.1%) were fed with combined breast milk and baby formula. The 95% confidence intervals of serum immunoglobulins and IgG subgroups were as follows: IgG, 652-722 mg/dL; IgA, 6-8 mg/dL; IgM, 27-35 mg/dL; IgG1, 495.7-544.3 mg/dL; IgG2, 139.6-169.5 mg/dL; IgG3, 22.7-27.7 mg/dL; and IgG4, 21.5-33.7 mg/dL. There was no significant correlation between any demographic characteristic and any immunoglobulin type. A low-moderate but significant negative correlation (r: -0.34) was found between birth length and IgA and a low-moderate but significant positive correlation (r: 0.32) was found between head circumference and IgM level. CONCLUSION: Our study provided usable data on the normal values of serum IgG, IgA, IgM, and IgG subgroups among healthy Turkish new-borns. This study is thought to be one of the most standardized and reliable reference sources for our country.