The Importance of determining levels of immunoglobulin and IgG subclasses in neonates in Trinidad - abstract

ABSTRACT

The occurence of multiple outbreaks of contagious diseases in Trinidad over the past decade led to an investigation of the role of immunoglobulin levels and IgG subclasses in neonates for whom there had hitherto been no established baseline. The mean immunoglobulin levels obtained for Trinidad were as follows IgG 1,232 ñ 225 mg/d, IgA 1.4 ñ 3 mg/d, IgM 12 ñ 11 mg/d. For the IgG subclass determinations, the values obtained were IgG1 840 ñ 182 mg/d, IgG2 21 ñ 115 mg/d, IgG 364 ñ 62 mg/d and IgG4 111 ñ 94 mg/d. The mean G, A, M, G1, Gs and G4 concentrations differed significantly from those obtained in the USA. When our IgG subclass means were compared with those in a Swedish study, IgG1 and IgG4 were elevated. During the course of the study, baseline values were also determined for beta 2 microglobulin (0.44 ñ 1.6 mg/d) and C reactive protein. Normal neonates showed no production of CRP. However, 4 apparently normal neonates gave values ranging from 0.2 to 6.1 mg/d. Within 72-96 hours, all 4 developed pneumonia, jaundice and/or sepis. This suggests that CRP can be employed as an indicator for infection in neonates in the absence of overt clinical symptoms (AU)