Serum Th1/Th2 and macrophage lineage cytokines in leprosy; correlation with circulating CD4 + CD25 high FoxP3 + T-regs cells Marwa Abdallah 1 , Enas A. S. Attia 1 , Abeer A. Saad 2 , Ekramy A. El-Khateeb 1 , Rania A. Lotfi 1 , Mahmoud Abdallah 1 and Dina El-Shennawy 2 1 Department of Dermatology, Venereology and Andrology, Faculty of Medicine, Ain Shams University, Cairo, Egypt; 2 Department of Clinical Pathology, Faculty of Medicine, Ain Shams University, Cairo, Egypt Correspondence: Enas A. S. Attia, Department of Dermatology, Venereology and Andrology, Faculty of Medicine, Ain Shams University, Cairo 11381, Egypt, Tel./Fax: +202 26830767, e-mail: annosah1974@yahoo.com Abstract: Not only macrophages, T-helper (Th)1 and Th2, but also CD4 + CD25 high FoxP3 + regulatory T cells (T-regs) are involved in immune response to Mycobacterium leprae. We aimed to evaluate serum interleukin (IL)-1b and IL-12p70 (macrophage cytokines), interferon-c (IFN-c) (Th1 cytokine), IL-4 (Th2 cytokine) and circulating CD4 + CD25 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 (RL1) and erythema nodosum leprosum (ENL). Serum IL-12p70, IFN-c and IL-4 were significantly higher in patients versus controls (P < 0.05). Serum IL-4 was highest in LL and lowest in RL1 (P = 0.003). Serum IL-1b levels was significantly higher in multibacillary versus paucibacillary patients (P = 0.006). Significantly higher T-regs levels was detected in TT, RL1 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- c correlated positively with T-regs but negatively with IL-1 b (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, RL1 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-c 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-1b probably has a pro-inflammatory role in multibacillary patients as correlated with T-effs%. Key words: interferon-c – interleukins – leprosy – T-regs Accepted for publication 24 July 2014 Introduction Leprosy is a chronic granulomatous infection principally affecting the skin and peripheral nerves caused by Mycobacterium leprae (M. leprae) (1). Host immunity to M. leprae determines the diver- sity of clinical manifestations seen in patients, from tuberculoid leprosy (TT) with robust production of T-helper (Th)1-type cyto- kines, to lepromatous disease (LL), characterized by elevated levels of Th2-type cytokines (2). Between those two polar forms lie the borderline forms with the extent of the disease reflecting the balance between cellular mediated immunity (CMI) and the bacil- lary load. These forms are liable to reactional leprosy type 1 (RL1), with a predominantly Th1 cytokine profile (3,4). The ery- thema nodosum leprosum (ENL), occurring in borderline leprosy (BL) and LL leprosy patients, is a more systemic reaction than the previous (5,6). Pure neural leprosy (PNL) is a special type where no skin lesions, with thickened and/or tender nerves (7). Macrophages play an important role in body’s attempt to elimi- nate M. leprae. When these cells encounter M. leprae, they pro- duce cytokines, including interleukin (IL)-1 and IL-12. These cytokines then stimulate the number and activity of other macro- phages (8). IL-1b, the prominent form of IL-1, has many biologi- cal activities, including fever, anorexia and leukocytosis. It also stimulates other cytokines, chemokines and acute-phase reactants (9). IL-12, with its biologically active IL-12p70 heterodimer (10), is involved in the differentiation of naive T cells into Th1 cells. IL-12 was also shown to mediate enhancement of the cytotoxic activity of natural killer cells and cytotoxic T lymphocytes (11). The above-mentioned data demonstrate the immunopathologi- cal interactions between Th1 and Th2 cytokines (12,13) and acti- vated macrophage products (monokines) in leprosy (14). In a previous publication, we demonstrated also a possible role of CD4 + CD25 high FoxP3 + regulatory T cells (T-regs) in leprosy (15). Thus, the aim of this study was to evaluate serum levels of IL-1 and IL-12 (monocyte lineage cytokines), IFN-c (Th1 cytokine), IL-4 (Th2 cytokine), as well as circulating CD4 + CD25 high FoxP3 + T-regs, in untreated patients with different types of leprosy. Methods This study was conducted on 43 untreated leprotic patients attending at El Qal’aa (Citadel) Dermatology and Leprosy Hospi- tal, Cairo, Egypt, and 40 healthy volunteers as controls, after sign- ing an informed consent, over a period of 14 months. The study was conducted according to the Declaration of Helsinki Principles and was approved by the medical ethical committee of Ain Shams University. Patients were evaluated according to clinical examina- tion, slit skin smear examination (SSS) and histopathological examination and were divided into six groups: TT; PNL; border- line leprosy [borderline tuberculoid (BT), mid-borderline (BB) and BL]; LL: RL1; and ENL. Patients were also grouped according 742 ª 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd Experimental Dermatology, 2014, 23, 742–747 DOI: 10.1111/exd.12529 www.wileyonlinelibrary.com/journal/EXD Original Article