Therapeutic prospects for early asthma.

What we know: There is strong evidence that T cells contribute to asthma pathogenesis. Immune-modulating drugs that dampen, turn off or redirect T cells, and adjuvants that trigger T(H)1 immune responses, are potential therapies for preventing asthma. Current T cell immune suppressors are too toxic to use in very young children with asthma. Immune-modulation research is identifying pathways that might lead to preventive therapy for asthma. Inhibitors of T cell cytokines do not reduce asthma in adults. What we need to know: Is immune deviation from a T(H)2-type response towards a T(H)1-type response a sound strategy given that mixed T(H)1/T(H)2 responses are already known to occur in asthma? What, specifically, triggers the development of armed effector lymphocytes that are thought to cause tissue damage in asthma? Are the changes in lung structure that are observed in chronic asthma really dependent on T cell mechanisms? Can abnormal lung structure be improved or normalised? Would any of these strategies be safer and more effective than current therapies?