CD40LG and obstructive sleep apnea syndrome: The serum IgM, IgA and IgG levels of children one month and six months after adenoidectomy and tonsillectomy were similar to those before surgeries.10 Likewise, Li et al. found that the serum IgM, IgA and IgG levels of adults with OSAHS were not significantly different from those of normal controls, and the preoperative and postoperative levels did not differ significantly either.