Força de preensão manual e funcionalidade em pessoas atingidas pela hanseníase, seus contatos intradimiciliares e escolares de área endêmica: Correlação com biomarcador molecular e sorológico de infecção pelo Mycobacterium leprae

Abstract

Leprosy can cause significant physical disabilities if not early diagnosed and treated. The diagnosis is essentially clinical, through dermatoneurological examination, including a subjective and low sensitivity manual muscle strength test. Household contacts of untreated patients are most at risk of developing the disease. Early diagnosis is essential for breaking the chain of transmission and preventing disability. In this context, the use of dynamometry provides objective data on handgrip strength through a simple and cost-effective clinical test, and with functional tests, could contribute to an early detection of peripheral nerve disorders. The aim of this study is to correlate handgrip strength and functionality data with biomarkers of Mycobacterium leprae infection among people affected by leprosy, their household contacts, and schoolchildren in endemic areas. The study was approved (report 5384136) and carried out in Imperatriz (MA), São Luís (MA) and Marituba (PA). Subjects diagnosed with leprosy, their household contacts and school contacts <15 years old were clinically examined and have biological samples collected for the detection of IgM-anti-PGL-I antibodies and for the molecular detection of M. leprae by means of RT-PCR. Strength was measured using a handheld dynamometer, while we used a scale and functional tests to assess functionality. A total of 179 subjects were included in the study, 94 females (52.51%), 67 cases of leprosy (28 new cases and 10 index cases) and 60 healthy household contacts (36.5 ±14.69 years) and 52 healthy schoolchildren from an endemic region. We found a significant prevalence of loss of muscle weakness (p=0.0003) in leprosy cases compared to healthy individuals. Healthy male subjects >15 years old had significantly higher mean values of grip strength and pinch strength (p<0.05) compared to male leprosy cases, except for the pulp pinch. Leprosy cases > 15 years old showed significant functional losses (p<0.05), evaluated by TFMJT and 9-PnB and a longer test time, when compared to the healthy group, mainly women. It was observed that leprosy cases had significantly more activity limitations when assessed on the SALSA scale (p<0.05). Subjects with changes in nerve palpation and decreased tactile sensitivity showed significantly more muscle weakness and functional loss (p<0.05). We found an inversely proportional correlation between anti-PGL-I IgM titers and muscle grip strength and pinch strength in individuals over 15 years of age (p<0.05). While muscle weakness was observed in most RT-PCR positive cases. Of the positive individuals for RT-PCR, 42.31% presented functional loss in the tests, showing a significantly longer time in the TFMJT (p=0.028). Those positive for RT-PCR presented significantly greater times in the block stacking (p=0.046) and feeding simulation (p=0.025) subtests. We observed muscle weakness in 28.75% and loss of function in 33.33% of subjects double positive for anti-PGL-I and RT-PCR. Therefore, these data show us that there may be motor and functional impairment in this population that is more vulnerable to the development of leprosy, where these tests can find disabilities, in addition to those of the traditional clinical evaluation.