Circulating cytokine profiles in leprosy patients.

BACKGROUND: Leprosy is a chronic infectious disease caused by Mycobacterium leprae which is an obligate intracellular pathogen. It is characterised by a broad spectrum of clinical forms dictated by the patient's immune response to the organism. The tuberculoid pole has good cell mediated immunity to M. leprae, with few lesions and bacilli while the lepromatous pole has poor immunity coupled with extensive involvement and greater bacillary load. METHODS: We studied serum levels of interferon gamma and interleukin 6 in 100 patients of untreated leprosy, compared them with 30 age and sex matched normal healthy controls and co-related them with different parts of the spectrum and reactional episodes. The purpose of this study was to delineate the role of cytokines and their clinical implications in the leprosy spectrum and during reactional episodes. RESULTS: We observed that mean cytokine levels were significantly higher in the patient group as compared to the controls. In the non reactional patient group, pure neuritic leprosy patients showed highest levels of INFgamma which were directly proportional to the extent of nerve involvement. Lepromatous leprosy patients had the highest levels of IL6. Bacteriological index demonstrated a negative and positive corelation with INFgamma and IL 6 levels respectively. Type I and Type II reactional patients had higher levels of INFgamma and IL 6 respectively as compared to nonreactional patients. CONCLUSIONS: Our results suggest that pure neuritic leprosy and borderline tuberculoid patients in type I reaction are at greatest risk for nerve and tissue damage. Thus cytokines have the potential to play a significant role in classification, prognosis and treatment of leprosy.

A study of serum nitric oxide levels in psoriasis.

BACKGROUND: M any inter and intracellular mediators have been implicated in the pathogenesis of psoriasis. Nitric oxide has been shown to play an important role in many diseases. Previous studies have demonstrated raised levels of nitric oxide in psoriatic plaques which may be attributed to its effect on keratinocytes, on local cGMP levels or its ability to induce angiogenesis. AIMS: To detect serum nitric oxide (NO) levels in patients with active psoriasis, to correlate these levels with severity of disease and compare them with those in normal individuals. METHODS: Thirty six patients with active psoriasis were selected after written consent. All patients on topical or systemic treatment for fifteen days prior to the study were excluded. Disease severity was assessed by PASI score and serum nitric oxide levels were detected by Greiss method and compared with age and sex matched controls. Statistical analysis of all data was done by unpaired t test. RESULTS: Out of 36 patients, 30 had chronic plaque psoriasis (mean NO 157.5), 4 had erythroderma (mean NO 120.2) and 2 had generalized pustular psoriasis (mean NO 144.3). The mean NO level in the psoriatic group was 157.7 with SD 50.4 while in the control group it was 32.8 with SD 4.03. The difference was statistically significant (t=13.8, P < 0.001). In the chronic plaque group, as the duration of disease increased, the NO levels increased significantly. CONCLUSIONS: Nitric oxide levels were significantly increased in patients with psoriasis and these levels showed a positive correlation with severity and duration in the chronic plaque type group.