Serum Th1/Th2 and macrophage lineage cytokines in leprosy; correlation with circulating CD 4 + CD 25 high FoxP3 + T‐regs cells

Not only macrophages, T‐helper (Th)1 and Th2 , but also CD 4 + CD 25 high FoxP3 + regulatory T cells (T‐regs) are involved in immune response to Mycobacterium leprae . We aimed to evaluate serum interleukin ( IL )‐1 β and IL ‐12p70 (macrophage cytokines), interferon‐ γ ( IFN ‐ γ ) (Th1 cytokine), IL ‐4 (Th2 cytokine) and circulating CD 4 + CD 25 high FoxP3 + T‐regs, in untreated leprosy patients. Forty three patients and 40 controls were assessed for the mentioned cytokines using ELISA . Patients were assessed for circulating T‐regs using flow cytometry. Patients were subgrouped into tuberculoid ( TT ), pure neural leprosy ( PNL ), borderline cases, lepromatous ( LL ), type 1 reactional leprosy ( RL 1) and erythema nodosum leprosum ( ENL ). Serum IL ‐12p70, IFN ‐ γ and IL ‐4 were significantly higher in patients versus controls ( P  <   0.05). Serum IL ‐4 was highest in LL and lowest in RL 1 ( P  =   0.003). Serum IL ‐1 β levels was significantly higher in multibacillary versus paucibacillary patients ( P  =   0.006). Significantly higher T‐regs levels was detected in TT , RL 1 and PNL , while the lowest levels in ENL ( P  <   0.001), with significant differences versus controls ( P  <   0.05). FoxP3 expression% was significantly lower in PNL than other patients and controls ( P  <   0.05). T‐regs/T‐effs was lowest in ENL ( P  <   0.05). IFN ‐ γ correlated positively with T‐regs but negatively with IL ‐1 β ( P  =   0.041&0.046 respectively), which correlated positively with T‐effs%( P  =   0.05). IL ‐4 correlated positively with T‐regs FoxP3 expression% ( P  =   0.009). We concluded that: Circulating T‐regs were increased in TT , RL 1 and PNL patients, known of relatively high cell‐mediated immunity. This finding was supported by low FoxP3 expression (in PNL ) and correlation between T‐regs count and IFN ‐ γ level. Overproduction of IL ‐4 in LL may infer liability to develop ENL , with disease progression and immune hyperactivation, marked by deficient T‐regs and increased T‐regs FoxP3 expression%. IL ‐1 β probably has a pro‐inflammatory role in multibacillary patients as correlated with T‐effs%.