Serum nitric oxide metabolites in leprosy patients as a parameter of prognostic value
Background: Leprosy is a chronic infectious disease caused by the obligate intracellular microorganism Mycobacterium leprae that tends to infect the skin and peripheral nerves. Nitric oxide (NO) plays a role not only in limiting bacterial growth, but also in limiting the damaging of immunopathological consequences of chronic mycobacterial infection.
Objective: To assess NO metabolites level in sera of leprosy patients across the spectrum of the disease as a possible parameter of prognostic value and as an indicator of disease state.
Patients and methods: This case–control study was conducted on 80 leprosy patients who were selected from Benha Dermatology and Leprosy Clinic, Benha University Hospital, and Abu Zaabal Leprosarium. Twenty age-matched and sex-matched healthy volunteers were included as the control group. Patients were subjected to history taking, clinical examination, and dermatological examination and were divided into groups according to the WHO classification. Blood samples were collected from both patients and controls for assessment of NO metabolites [nitrite (NO2) and nitrate (NO3)] serum levels by ELISA.
Results: Our results showed that comparison of the mean values of serum NO metabolites levels for each group of untreated patients versus the control group revealed increased serum NO metabolites levels in untreated patients, whereas comparison for each group of treated patients versus the control group revealed decreased serum NO metabolites levels in treated patients. The present study also showed that, in paucibacillary leprosy patients, in multibacillary leprosy patients, and in type 1 reaction patients, receiver operating characteristic curve at cutoff value of 155.97, 195.98, and 157.17 µmol of serum NO2, respectively, has sensitivity of 80, 67, and 73% and specificity of 90, 93, and 93%, respectively.
Conclusion: Serum NO metabolites levels of leprosy patients increase during the disease and decrease after treatment. Serum NO metabolites in leprosy patients can be used as a parameter of prognostic value.