Activation and cytokine profile of monocyte derived dendritic cells in leprosy: in vitro stimulation by sonicated Mycobacterium leprae induces decreased level of IL-12p70 in lepromatous leprosy

Dendritic cells (DCs) play a pivotal role in the connection of innate and adaptive immunity of hosts to mycobacterial infection. Studies on the interaction of monocyte-derived DCs (MO-DCs) using Mycobacterium leprae in leprosy patients are rare. The present study demonstrated that the differentiation of MOs to DCs was similar in all forms of leprosy compared to normal healthy individuals. In vitro stimulation of immature MO-DCs with sonicated M. leprae induced variable degrees of DC maturation as determined by the increased expression of HLA-DR, CD40, CD80 and CD86, but not CD83, in all studied groups. The production of different cytokines by the MO-DCs appeared similar in all of the studied groups under similar conditions. However, the production of interleukin (IL)-12p70 by MO-DCs from lepromatous (LL) leprosy patients after in vitro stimulation with M. lepraewas lower than tuberculoid leprosy patients and healthy individuals, even after CD40 ligation with CD40 ligand-transfected cells. The present cumulative findings suggest that the MO-DCs of LL patients are generally a weak producer of IL-12p70 despite the moderate activating properties ofM. leprae. These results may explain the poor M. leprae-specific cell-mediated immunity in the LL type of leprosy.

Quantificação dos níveis séricos de leptina na Hanseníase / Quantification of serum leptin levels in leprosy

A leptina é uma adipocina com semelhanças estruturais e funcionais às citocinas pró-inflamatórias, contribuindo para a diferenciação de células Th1, e parece estar envolvida na resposta imune a agentes infecciosos. Na hanseníase, doença infecciosa crônica causada pelo Mycobacterium leprae, cujas manifestações clínicas dependem da resposta imune do hospedeiro, não há relatos sobre o papel da leptina. Neste estudo piloto foram quantificados os níveis séricos de leptina em pacientes recém-diagnosticados com as diferentes formas clínicas da doença, pacientes hansenianos em reação tipo 1 e 2,contatos de pacientes hansenianos e controles saudá-veis (237 amostras de soros: 165 homens e 72 mulheres).No sexo masculino, as formas TT e BB apresentaram concentrações próximas àquelas observadas nos controles enquanto os grupos I, BT, BV, VV, reação do tipo1 e 2 apresentaram médias inferiores à observada nos controles e contatos, sendo que nos BV e VV foram observados os menores níveis de leptina. No sexo feminino verificamos uma grande variação entre os valores observados nos diferentes grupos. O grupo BV apresentou níveis maiores de leptina enquanto os grupos I, TT, BT e BB apresentaram média próxima àquela observada nos contatos e controles. Pacientes do grupo VV e em reação tipo 1 e 2 apresentaram médias inferiores ao observado nos contatos e controles. As diferenças observadas tanto em homens quanto em mulheres não foram estatisticamente significantes. Em nossos achados há uma tendência a níveis mais baixos de leptina nas formas multibacilares, contudo, estes resultados não permitem associação desses níveis com qualquer forma clínica da hanseníase.

Leptin, an adipokine with structural and functional similaritiesto proinflammatory cytokines that contributesto the differentiation of T helper-1 cells, seems to beinvolved in the immune response to infectious agents.In leprosy, a chronic infectious disease caused by Mycobacteriumleprae, whose clinical manifestations depend on the host immune response, there are no reports onthe role of leptin. In this pilot study the serum leptin levelswere quantified in newly diagnosed patients withdifferent clinical forms of leprosy, patients with type 1and 2 reaction, contacts of leprosy patients and healthycontrols (237 serum samples:165 men and 72 women).In males, TT and BB patients showed concentrations closeto those observed in controls while groups I, BT, BV,VV, type 1 and 2 reactional patients had lower means incomparison to controls and contacts, whereas in BV andVV patients it were observed the lowest levels of leptin.In females, we found a wide variation between the valuesobserved in the different groups. The BV group hadhigher levels of leptin while groups I, TT, BT and BB hadaverages closed to that observed in contacts and controls.The differences observed in both men and womenwere not statistically significant. Our findings show atendency to lower levels of leptin in multibacillary patients,however, these results do not allow any associationof leptin with leprosy clinical forms.