Investigating the Changes of Hormonal and Cytokine Levels in Patients with Human Cutaneous Leishmaniasis

Leishmaniasis is a disease caused by the Leishmania parasite and transmitted through the bite of a specific type of mosquito. This disease appears in three forms: cutaneous, cutaneous-mucosal, and visceral. Cutaneous leishmaniasis (CL) is a tropical disease caused by an intracellular parasite of the genus Leishmania. This disease is the most important endemic disease in Iran. Changes in plasma hormone levels have been reported in many parasitic infections, and changes in hormone levels can lead to changes in cytokine profiles. The immune-endocrine system interaction plays an important role in the pathogenesis of cutaneous leishmaniasis. Also, the level of some hormones is related to the level of cytokines and clinical symptoms. The purpose of this study is to evaluate the plasma levels of hormones (cortisol, DHEA-S, estradiol, prolactin, and testosterone) and cytokines (interferon-gamma, TNF-α, IL-4, and IL-10) in patients with cutaneous leishmaniasis and the control group.

This study was carried out in the cities of Abadan and Khorramshahr located in Khuzestan province in the southwest of Iran. After obtaining permission from the ethics committee of Behbahan Faculty of Medical Sciences and obtaining consent from all subjects under the study, a questionnaire including demographic information was completed by all subjects participating in the study. An amount of 5 ml of blood was prepared from each person under study and after centrifugation at 4000 rpm for 10 minutes, the serum was kept at minus 20 degrees Celsius until the day of the experiment to measure hormones and cytokines. In the present study, 40 patients with cutaneous leishmaniasis and 40 healthy patients with no history of cutaneous leishmaniasis were selected. Using laboratory kits, the plasma levels of the hormones cortisol, estradiol, dehydroepiandrosterone (DHEA), prolactin, and testosterone, as well as the plasma levels of cytokines tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), interleukin 1 (IL-1) and interferon-gamma (IFN-γ) were measured.  Hormone concentration in the control group and patients was compared using the Mann-Whitney test. The relationship between the levels of cytokines and hormones was investigated by Spearman's test. All statistical tests were performed using Graph Pad software version 5 (GraphPad Software Inc., San Diego, CA, USA).

The results of this study showed that the plasma levels of cortisol, estradiol, DHEA, prolactin, and testosterone were lower in patients than in healthy individuals and these results were statistically significant (P<0.05). Plasma levels of TNF-α, IL-6, and IL-1 were higher in patients with cutaneous leishmaniasis compared to healthy subjects(P>0.05). In addition, the plasma level of IFN-γ was lower in patients than in healthy subjects, and these results were statistically significant(P>0.05).

According to the results of the present study, it seems that endocrine-immune system changes in cutaneous leishmaniasis patients are beneficial for the host and helps to heal the lesions. Also, knowing as much as possible about the endocrine mechanisms involved in the regulation of the immune response in cutaneous leishmaniasis can be important for the diagnosis of the disease or the drug treatment of this disease.