MYELOID-DERIVED SUPPRESSOR CELLS TWO YEARS AFTER HEPATITIS C VIRUS ERADICATION USING DIRECTLY ACTING ANTIVIRALS.

BACKGROUND: Myeloid-derived suppressor cells (MDSCs) have immature morphology, relatively weak phagocytic activity, as well as some immunosuppressive functions. The capacity of MDSCs to inhibit T-cell-mediated immunological responses is their most notable functional characteristic. Down-regulating antitumor immune surveillance is one way that the expansion and activation of MDSCs contribute significantly to the occurrence and progression of tumors. Increased levels of MDSCs in patients with chronic hepatitis C virus (HCV) infection could suppress T-cell responses, promoting viral escape and hepatitis progression. This may make HCV-infected individuals more vulnerable to severe infections, hepatic and extra-hepatic tumors, and a diminished capacity to react to immunization. It is still unknown if effective HCV eradication with directly acting antivirals (DAAs) can restore immune functions and immune surveillance capacity. OBJECTIVE: The purpose of this study was to observe the frequency of M-MDSCs (CD33+, CD11b+, and HLA-DR) in patients with a previous history of HCV, 2-3 years after virus eradication using DAA therapy. METHODS: This study was conducted on 110 subjects: fifty-five subjects without liver cirrhosis who were treated with HCV using DAAs and attained SVR for a period of 2-3 years and 55 age- and gender-matched healthy controls. The study was conducted during the period from January to July 2022. Patients were recruited from the National Viral Hepatitis Treatment Unit, Alexandria University Hepatology outpatient clinic, and the Alexandria University Tropical Medicine outpatient clinic. The frequencies of MDSCs (CD33+CD11b + HLA-DR-) by flow cytometry were assessed. RESULTS: Even after the virus had been eradicated for longer than two years, MDSC levels in HCV-treated individuals were found to be considerably higher. In the HCV-treated group, the median number of MDSCs was 5, with an interquartile range (IQR) of 3.79-7.69. In contrast, the median for the control group was 3.1, with an IQR of 1.4-3.2 (P˂0.001). CONCLUSION: Successful DAA therapy leads to slow and partial immunological reconstitution, as demonstrated by the failure to attain normal levels of MDSC's 2 years after successful HCV eradication despite the normalization of laboratory parameters as well as the absence of liver fibrosis. The clinical implications of these findings should be thoroughly studied.

Células supressoras mieloides derivadas dois anos após a erradicação do vírus da hepatite C usando antivirais de ação direta / Myeloid-derived suppressor cells two years after hepatitis c virus eradication using directly acting antivirals

ABSTRACT Background: Myeloid-derived suppressor cells (MDSCs) have immature morphology, relatively weak phagocytic activity, as well as some immunosuppressive functions. The capacity of MDSCs to inhibit T-cell-mediated immunological responses is their most notable functional characteristic. Down-regulating antitumor immune surveillance is one way that the expansion and activation of MDSCs contribute significantly to the occurrence and progression of tumors. Increased levels of MDSCs in patients with chronic hepatitis C virus (HCV) infection could suppress T-cell responses, promoting viral escape and hepatitis progression. This may make HCV-infected individuals more vulnerable to severe infections, hepatic and extra-hepatic tumors, and a diminished capacity to react to immunization. It is still unknown if effective HCV eradication with directly acting antivirals (DAAs) can restore immune functions and immune surveillance capacity. Objective: The purpose of this study was to observe the frequency of M-MDSCs (CD33+, CD11b+, and HLA-DR) in patients with a previous history of HCV, 2-3 years after virus eradication using DAA therapy. Methods: This study was conducted on 110 subjects: fifty-five subjects without liver cirrhosis who were treated with HCV using DAAs and attained SVR for a period of 2-3 years and 55 age- and gender-matched healthy controls. The study was conducted during the period from January to July 2022. Patients were recruited from the National Viral Hepatitis Treatment Unit, Alexandria University Hepatology outpatient clinic, and the Alexandria University Tropical Medicine outpatient clinic. The frequencies of MDSCs (CD33+CD11b + HLA-DR-) by flow cytometry were assessed. Results: Even after the virus had been eradicated for longer than two years, MDSC levels in HCV-treated individuals were found to be considerably higher. In the HCV-treated group, the median number of MDSCs was 5, with an interquartile range (IQR) of 3.79-7.69. In contrast, the median for the control group was 3.1, with an IQR of 1.4-3.2 (P˂0.001). Conclusion: Successful DAA therapy leads to slow and partial immunological reconstitution, as demonstrated by the failure to attain normal levels of MDSC's 2 years after successful HCV eradication despite the normalization of laboratory parameters as well as the absence of liver fibrosis. The clinical implications of these findings should be thoroughly studied.

RESUMO Contexto: As células supressoras derivadas de mieloides (CSDMs) possuem morfologia imatura, atividade fagocítica relativamente fraca e algumas funções imunossupressoras. A capacidade das CSDMs de inibir respostas imunológicas mediadas por células T é sua característica funcional mais notável. A expansão e ativação das CSDMs contribuem significativamente para a ocorrência e progressão de tumores, regulando negativamente a vigilância imunológica antitumoral. Níveis aumentados de CSDMs em pacientes com infecção crônica pelo vírus da hepatite C (HCV) poderiam suprimir respostas das células T, promovendo a fuga viral e a progressão da hepatite. Isso pode tornar os indivíduos infectados pelo HCV mais vulneráveis a infecções graves, tumores hepáticos e extra-hepáticos, e a uma capacidade diminuída de reagir à imunização. Ainda não se sabe se a erradicação eficaz do HCV com antivirais de ação direta (AAD) pode restaurar as funções imunológicas e a capacidade de vigilância imunológica. Objetivo: O objetivo deste estudo foi observar a frequência de M-CSDMs (CD33+, CD11b+ e HLA-DR-) em pacientes com histórico anterior de HCV, 2-3 anos após a erradicação do vírus usando terapia com AADs. Métodos: Este estudo foi realizado em 110 indivíduos: 55 indivíduos sem cirrose hepática que foram tratados com AADs para HCV e atingiram resposta virológica sustentada (SVR) por um período de 2-3 anos e 55 controles saudáveis pareados por idade e gênero. O estudo foi conduzido no período de janeiro a julho de 2022. Os pacientes foram recrutados da Unidade Nacional de Tratamento de Hepatites Virais, da clínica ambulatorial de Hepatologia da Universidade de Alexandria e da clínica ambulatorial de Medicina Tropical da Universidade de Alexandria. As frequências de CSDMs (CD33+CD11b+HLA-DR-) foram avaliadas por citometria de fluxo. Resultados: Mesmo após a erradicação do vírus por mais de dois anos, os níveis de CSDMs em indivíduos tratados para HCV foram consideravelmente mais altos. No grupo tratado para HCV, o número mediano de CSDMs foi de 5, com um intervalo interquartil (IQR) de 3,79-7,69. Em contraste, a mediana para o grupo controle foi de 3,1, com um IQR de 1,4-3,2 (P<0,001). Conclusão: A terapia bem-sucedida com AADs leva a uma reconstituição imunológica lenta e parcial, como demonstrado pela falha em atingir níveis normais de CSDMs 2 anos após a erradicação bem-sucedida do HCV, apesar da normalização dos parâmetros laboratoriais e da ausência de fibrose hepática. As implicações clínicas desses achados devem ser estudadas minuciosamente.