Serum Irisin Level In Leprosy Patients

Leprosy is a chronic granulomatous infectious disease which infects mainly superficial peripheral nerves, mucosa of upper respiratory tract, testicles, bones, and eyes. It's an intracellular infection caused by the acid-fast bacillus, Mycobacterium leprae.

Both age and sex are important risk factors for leprosy infection, adolescents aged between 10 and 19 years and adults aged more than 30 years are more liable to leprosy, and the possibility of leprosy infection of adult males is twice as much as adult females.

Leprosy evolution involves complex host immune mechanisms that influence the clinical presentation of the disease . the spectral pathology of leprosy can be diagnosed by using two coexisting classification systems. The WHO classification system which is based on the number of lesions and Ridley and Jopling classification system which is based on the histopathology .

The WHO classification system includes individuals with more than five lesions which are classified as multibacillary (MB) patients, and individuals with less than five lesions which are classified as paucibacillary (PB) patients .While Ridley and Jopling classification system includes tuberculoid leprosy (TT), lepromatous leprosy (LL) and borderline phenotypes: {borderline tuberculoid (BT), mid-borderline (BB), and borderline lepromatous (BL).

Tuberculoid leprosy (TT) is characterized by the presence of one to three cutaneous lesions, called plaques. These lesions are circular or oval, erythematous/hypopigmented, hairless, scaly, dry and anesthetic. On the other hand, lepromatous leprosy (LL) is characterized by extensive and multiple bilateral lesions, which may include macules, papules, nodules, and plaques .

The majority of patients, however, present with the borderline phenotypes. In these phenotypes, the bacterial load correlates with the histological features, borderline tuberculoid (BT) being more closely related to tuberculoid leprosy( TT) patients while borderline lepromatous (BL) to lepromatous leprosy (LL) patients. The borderline states are immunologically unstable and susceptible to the occurrence of leprosy reactions.

In 1991 the World Health Assembly decided to 'eliminate leprosy as a public health problem' by the year 2000. Elimination was defined as decreasing the disease prevalence globally to less than 1 case per 10,000 populations. In 2000 the World Health Organization (WHO) announced that elimination was reached globally.

Irisin is a protein formed of 112 amino acids. It was discovered in 2012 at Harvard University. And named after an ancient Goddess called Iris, who served as a messenger among the Gods in Greek mythology.

Irisin has been linked to many metabolic diseases, including obesity, lipid metabolism ,cardiovascular disease (CVD), type 2 diabetes mellitus (T2DM) ,polycystic ovary syndrome (PCOS) ,Nonalcoholic fatty liver disease (NAFLD) and metabolic bone diseases .