CD40LG and infection: A postmortem serum sample tested at CDC yielded serologic evidence of recent infection with B. burgdorferi, reacting strongly in both whole cell sonicate (WCS) and C6 enzyme immunoassay (EIA), and against all three scored bands (23 kDa, 39 kDa, and 41 kDa) by immunoglobulin M (IgM) Western blot.