Table 2.

Evidence suggestive of a role of antibody-mediated immunity in prevention of infection or limiting severity of disease.

	Prevention of infection	Limiting severity of disease	Mucosal immunity
Clinical observation	•High titres of IgG against PPD seen in persistently exposed but TST- negative individuals [45] •Strong antibody responses against M.tb surface in healthy controls from high burden country [47]	•Lack of antibodies against LAM, membrane vesicles and 38-kDa antigen associated with risk of extra-pulmonary disease [34], [36], [44] •Higher titres of IgG against Ag85A associated with reduced risk of disease in infants [37]	•IgA against HrpA associated with improved severity markers on presentation in active TB disease [40] •Oral vaccination with BCG is able to induce anti-LAM sIgA in respiratory mucosa [134]
Experimental models	•No studies available to demonstrate that antibodies prevent acquisition of infection with M.tb	•Serum enriched for antibodies against LAM enhances intracellular killing of M.tb [81] •IVIG improves granuloma organization and decreases lung CFU in mouse models [85]	•IgAKO and pIgRKO mice more susceptible to M.tb [88], [94] •Prophylactic intra-tracheal human secretory IgA from colostrum can protect mice against M.tb challenge [96]
Monoclonal antibodies	•MAb against MPT51 agglutinates cultures of M.tb CDC1551 and may show immune exclusion mechanism [107]	•Intravenous Anti-LAM mAb enhances granuloma formation and prolongs survival in mice [100] •Anti-HBHA mAb limits dissemination of BCG in mice [103]	•Passive immunotherapy with IgA mAb against Acr of protective benefit in mouse model [104]