Tetanus toxoid is a protein antigen and elicits a strong specific antibody response. In our experience, impaired response to tetanus toxoid is observed only in severe immune deficiency; even patients with common variable immunodeficiency who have impaired specific antibody response to pneumococci do not display impaired specific antibody response to tetanus toxoid. Only two patients in this study had impaired protective levels to most of the 14 polysaccharide antigens; the majority of patients had impaired responses to serotypes

3, 8, 9N and 12F. Oxelius et al.[3] reported normal responses to polysaccharide antigens in their mixed sample of 10 adults and children (although they had data only for pneumococcal serotypes 3, 6A, 19F and 23F). This is in contrast to a report by Popa et al.[8], who observed decreased response Tamoxifen to tetanus and Haemophilus influenza vaccines in IgG3-deficient adults. Soderstrom et al.[11] reported that 75% of Barasertib chemical structure adults with selective IgG3 deficiency had low B cell function, as defined by EBV- or PWM-stimulated protein

A plaque-forming cells lower than 50% of healthy controls. Data on T cell function in selective IgG3 deficiency are limited. We observed that 30–40% of patients display impaired T cell proliferative response to mitogens and recall antigens. Soderstrom et al.[11] reported decreased T cell function (defined as PHA or ConA stimulation indices of <0·8) in 40% of IgG3-deficient adult subjects. In their study, data were presented as stimulation index, Montelukast Sodium which may be skewed due to differences in background counts. In our study, we analysed data as net counts per minute after subtracting the background. T helper-1 (IFN-γ) and T helper-2 (IL-5) cytokine production was analysed in seven subjects; abnormal IFN-γ production was observed in one patient and abnormal IL-5 production in two patients. It is not possible to suggest the significance of these cytokine results in IgG3 subclass deficiency, as the number of samples tested is small. Finally, NK cell cytotoxicity

and neutrophil oxidative burst (reactive oxygen species generation) were relatively normal. In two patients oxidative burst was modestly reduced; however, it was not to a level observed in chronic granulomatous disease. Furthermore, patients did not have diabetes mellitus. In general, IgG1 or IgG2 deficiencies are reported to cause more severe infections, and there is greater acceptance of the use of immunoglobulin prophylaxis in such cases [7]. In our study, clinical response to IVIG was observed in the majority of patients with IgG3 deficiency. Six of 13 patients who received IVIG had dramatic relief from their recurrent infections, five patients experienced moderate clinical improvement and two patients had no response. We did not observe any correlation between response to IVIG and immunological parameters. However, our sample size is too small to reach a definitive conclusion. Olinder-Nielsen et al.