Thrombocytopenia as a marker of liver steatosis in a low-endemic area for schistosomiasis mansoni.

INTRODUCTION:: Thrombocytopenia is commonly found in patients living in highly endemic areas for Schistosoma mansoni. Recently, different degrees of liver steatosis have also been associated with low platelet counts worldwide. We investigated the association of platelet counts with hepatosplenic schistosomiasis and with liver steatosis in an area of low prevalence of schistosomiasis in Brazil. METHOD:: Pains, a city in the state of Minas Gerais, Brazil, had a population of 8,307 inhabitants and a schistosomiasis prevalence of 8%. Four micro-areas comprising 1,045 inhabitants were selected for this study. Blood sample was collected and a complete blood count (CBC) was performed. Eighty-seven (87) patients had low platelet counts (group 1 - 8.3%) and 94 volunteers presenting normal CBC were randomized (group 2 - 8.9%). They underwent clinical and ultrasound examinations. Liver steatosis was determined as either present or absent using abdominal ultrasound. A spleen > 12 cm in length, measured by ultrasound (US), was considered to be increased. Data collected were analyzed using SPSS software version 19.0. RESULTS:: Twenty-two patients (22/25.3%) in group 1 had liver steatosis compared with 11 volunteers (11.7%) in group 2 (p=0.02). Hepatosplenic schistosomiasis was diagnosed in two patients (p>0.05). CONCLUSION:: Thrombocytopenia was not a good marker of hepatosplenic schistosomiasis mansoni in a low prevalence area in Brazil. Liver steatosis was associated with thrombocytopenia in our study.

Thrombocytopenia as a marker of liver steatosis in a low-endemic area for schistosomiasis mansoni / Trombocitopenia como marcador de esteatose hepática em áreas de baixa endemicidade de esquistossomose mansoni

Summary Introduction: Thrombocytopenia is commonly found in patients living in highly endemic areas for Schistosoma mansoni. Recently, different degrees of liver steatosis have also been associated with low platelet counts worldwide. We investigated the association of platelet counts with hepatosplenic schistosomiasis and with liver steatosis in an area of low prevalence of schistosomiasis in Brazil. Method: Pains, a city in the state of Minas Gerais, Brazil, had a population of 8,307 inhabitants and a schistosomiasis prevalence of 8%. Four micro-areas comprising 1,045 inhabitants were selected for this study. Blood sample was collected and a complete blood count (CBC) was performed. Eighty-seven (87) patients had low platelet counts (group 1 - 8.3%) and 94 volunteers presenting normal CBC were randomized (group 2 - 8.9%). They underwent clinical and ultrasound examinations. Liver steatosis was determined as either present or absent using abdominal ultrasound. A spleen > 12 cm in length, measured by ultrasound (US), was considered to be increased. Data collected were analyzed using SPSS software version 19.0. Results: Twenty-two patients (22/25.3%) in group 1 had liver steatosis compared with 11 volunteers (11.7%) in group 2 (p=0.02). Hepatosplenic schistosomiasis was diagnosed in two patients (p>0.05). Conclusion: Thrombocytopenia was not a good marker of hepatosplenic schistosomiasis mansoni in a low prevalence area in Brazil. Liver steatosis was associated with thrombocytopenia in our study.

Resumo Introdução: Trombocitopenia é um achado comum em pacientes que residem em áreas com alta endemicidade de esquistossomose mansônica. Recentemente, diferentes graus de esteatose hepática também têm sido associados a níveis baixos de plaquetas em todo o mundo. Investigamos a associação de níveis séricos de plaquetas com a forma grave da esquistossomose e com esteatose hepática em área de baixa prevalência de esquistossomose no Brasil. Método: Pains, cidade localizada no estado de Minas Gerais/Brasil, tem população de 8.307 habitantes e prevalência de esquistossomose de 8%. Em quatro microáreas dessa região, 1.045 habitantes foram avaliados para o estudo. Amostra de sangue foi coletada para realização do hemograma. Oitenta e sete (87) pessoas com níveis baixos de plaquetas formaram o grupo 1 (8,3%), e 94 voluntários com hemograma normal foram randomizados para compor o grupo 2 (8,9%). Todos os participantes dos grupos 1 e 2 foram submetidos a exame clínico e ultrassonografia (US) abdominal. Esteatose hepática foi caracterizada como presente ou ausente pela ultrassonografia (US) abdominal. Baços com mais de 12 cm de comprimento à US foram considerados aumentados. Os dados coletados foram analisados pelo programa de estatística SPSS 19.0. Resultados: Vinte e dois (22) indivíduos do grupo 1 (25,3%) e 11 do grupo 2 apresentaram esteatose hepática (11,7%) (p=0,02). Esquistossomose hepatoesplênica foi diagnosticada em dois pacientes (p>0,05). Conclusão: Trombocitopenia não foi um bom marcador de esquistossomose mansônica hepatoesplênica em área de baixa prevalência da esquistossomose no Brasil. Esteatose hepática foi associada com trombocitopenia no presente estudo.

Natural Schistosoma mansoni Infection in the Wild Reservoir Nectomys squamipes Leads to Excessive Lipid Droplet Accumulation in Hepatocytes in the Absence of Liver Functional Impairment.

Schistosomiasis is a neglected tropical disease of a significant public health impact. The water rat Nectomys squamipes is one of the most important non-human hosts in the schistosomiasis mansoni transmission in Brazil, being considered a wild reservoir. Cellular mechanisms that contribute to the physiological adaptation of this rodent to the Schistosoma mansoni parasite are poorly understood. Here we identified, for the first time, that a hepatic steatosis, a condition characterized by excessive lipid accumulation with formation of lipid droplets (LDs) within hepatocytes, occurs in response to the natural S. mansoni infection of N. squamipes, captured in an endemic region. Significant increases of LD area in the hepatic tissue and LD numbers/hepatocyte, detected by quantitative histopathological and ultrastructural analyses, were paralleled by increased serum profile (total cholesterol and triglycerides) in infected compared to uninfected animals. Raman spectroscopy showed high content of polyunsaturated fatty acids (PUFAs) in the liver of both groups. MALDI-TOFF mass spectroscopy revealed an amplified pool of omega-6 PUFA arachidonic acid in the liver of infected animals. Assessment of liver functional activity by the levels of hepatic transaminases (ALT and AST) did not detect any alteration during the natural infection. In summary, this work demonstrates that the natural infection of the wild reservoir N. squamipes with S. mansoni elicits hepatic steatosis in the absence of liver functional harm and that accumulation of lipids, markedly PUFAs, coexists with low occurrence of inflammatory granulomatous processes, suggesting that lipid stores may be acting as a protective mechanism for dealing with the infection.