Which feature is commonly seen with defects in B cells?

• A. Absence or mild signs of inflammation
• B. Encapsulated bacteria infections
• C. Opportunistic infections with bacteria
• D. Rubella

Answer: (A)

B cells drive humoral immunity by producing antibodies that opsonize bacteria and activate the classical complement pathway. Without antibodies, the recruitment and activation of inflammatory cells are reduced, so infections can occur with less of the usual inflammatory response. This makes absence or mild signs of inflammation a common feature in B-cell defects, reflecting the diminished antibody- and complement-mediated inflammatory processes. While infections with encapsulated bacteria are indeed a risk due to poor opsonization, the typical clinical clue emphasized in B-cell disorders is a blunted inflammatory response rather than a pattern of pus-filled or intensely inflamed lesions.