RESUMO
Viral infections trigger inflammation by controlling ATP release. CD39 ectoenzymes hydrolyze ATP/ADP to AMP, which is converted by CD73 into anti-inflammatory adenosine (ADO). ADO is an anti-inflammatory and immunosuppressant molecule which can enhance viral persistence and severity. The CD39-CD73-adenosine axis contributes to the immunosuppressive T-reg microenvironment and may affect COVID-19 disease progression. Here, we investigated the link between CD39 expression, mostly on T-regs, and levels of CD73, adenosine, and adenosine receptors with COVID-19 severity and progression. Our study included 73 hospitalized COVID-19 patients, of which 33 were moderately affected and 40 suffered from severe infection. A flow cytometric analysis was used to analyze the frequency of T-regulatory cells (T-regs), CD39+ T-regs, and CD39+CD4+ T-cells. Plasma concentrations of adenosine, IL-10, and TGF-ß were quantified via an ELISA. An RT-qPCR was used to analyze the gene expression of CD73 and adenosine receptors (A1, A2A, A2B, and A3). T-reg cells were higher in COVID-19 patients compared to healthy controls (7.4 ± 0.79 vs. 2.4 ± 0.28; p < 0.0001). Patients also had a higher frequency of the CD39+ T-reg subset. In addition, patients who suffered from a severe form of the disease had higher CD39+ T-regs compared with moderately infected patients. CD39+CD4+ T cells were increased in patients compared to the control group. An analysis of serum adenosine levels showed a marked decrease in their levels in patients, particularly those suffering from severe illness. However, this was paralleled with a marked decline in the expression levels of CD73. IL-10 and TGF-ß levels were higher in COVID-19; in addition, their values were also higher in the severe group. In conclusion, there are distinct immunological alterations in CD39+ lymphocyte subsets and a dysregulation in the adenosine signaling pathway in COVID-19 patients which may contribute to immune dysfunction and disease progression. Understanding these immunological alterations in the different immune cell subsets and adenosine signaling provides valuable insights into the pathogenesis of the disease and may contribute to the development of novel therapeutic approaches targeting specific immune mechanisms.
Assuntos
Adenosina , COVID-19 , Linfócitos T Reguladores , Humanos , 5'-Nucleotidase/genética , 5'-Nucleotidase/metabolismo , Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Anti-Inflamatórios , Antígenos CD/genética , Antígenos CD/metabolismo , Progressão da Doença , Interleucina-10 , Receptores Purinérgicos P1/genética , Fator de Crescimento Transformador beta/genética , Linfócitos T Reguladores/metabolismoRESUMO
CD39 is a marker of immune cells such as lymphocytes and monocytes. The CD39/CD73 pathway hydrolyzes ATP into adenosine, which has a potent immunosuppressive effect. CD39 regulates the function of a variety of immunologic cells through the purinergic signaling pathways. CD39+ T cells have been implicated in viral infections, including Human Immunodeficiency Virus (HIV), Cytomegalovirus (CMV), viral hepatitis, and Corona Virus Disease 2019 (COVID-19) infections. The expression of CD39 is an indicator of lymphocyte exhaustion, which develops during chronicity. During RNA viral infections, the CD39 marker can profile the populations of CD4+ T lymphocytes into two populations, T-effector lymphocytes, and T-regulatory lymphocytes, where CD39 is predominantly expressed on the T-regulatory cells. The level of CD39 in T lymphocytes can predict the disease progression, antiviral immune responses, and the response to antiviral drugs. Besides, the percentage of CD39 and CD73 in B lymphocytes and monocytes can affect the status of viral infections. In this review, we investigate the impact of CD39 and CD39-expressing cells on viral infections and how the frequency and percentage of CD39+ immunologic cells determine disease prognosis.
RESUMO
Viruses can trigger glomerulonephritis (GN) development. Hepatitis viruses, especially Hepatitis C virus and Hepatitis B viruses, are examples of the viruses that trigger GN initiation or progression. However, the proof of a correlation between GN and Hepatitis E virus infection is not clear. Some studies confirmed the development of GN during acute or chronic HEV infections, mainly caused by genotype 3. While others reported that there is no relation between HEV exposure and GN development. A recent study showed that a reduced glomerular filtration rate was developed in 16% of acute HEV genotype 1 (HEV-1) infections that returned to normal during recovery. HEV-1 is endemic in Egypt with a high seroprevalence among villagers and pregnant women. There is no available data about a link between HEV and GN in Egypt. METHODS: GN patients (n = 43) and matched healthy subjects (n = 36) enrolled in Assiut University hospitals were included in this study. Blood samples were screened for hepatotropic pathogens. Tests for HEV markers such as HEV RNA and anti-HEV antibodies (IgM and IgG) were performed. Laboratory parameters were compared in HEV-seropositive and HEV-seronegative GN patients. RESULTS: Anti-HEV IgG was detected in 26 (60.5%) out of 43 GN patients. HEV seroprevalence was significantly higher in GN than in healthy controls, suggesting that HEV exposure is a risk factor for GN development. None of the GN patients nor the healthy subjects were positive for anti-HEV IgM or HEV RNA. There was no significant difference between seropositive and seronegative GN patients in terms of age, gender, albumin, kidney function profiles, or liver transaminases. However, anti-HEV IgG positive GN patients had higher bilirubin levels than anti-HEV IgG negative GN patients. HEV-seropositive GN patients had a significantly elevated AST level compared to HEV-seropositive healthy subjects. CONCLUSION: exposure to HEV infection could be complicated by the development of GN.
Assuntos
Glomerulonefrite , Vírus da Hepatite E , Hepatite E , Humanos , Feminino , Gravidez , Vírus da Hepatite E/genética , Estudos Soroepidemiológicos , Hepatite E/complicações , Hepatite E/epidemiologia , Anticorpos Anti-Hepatite , Glomerulonefrite/epidemiologia , RNA Viral , Imunoglobulina M , Imunoglobulina GRESUMO
Hepatitis A virus (HAV) and Hepatitis E virus (HEV) are transmitted through the fecal-oral route. HAV outbreaks and one HEV outbreak have been reported in Egypt. However, the impact of HAV-HEV co-infection is not known. In this study, we assessed HEV markers in acute HAV-infected patients (n = 57) enrolled in Assiut University hospitals. We found that 36.8% of HAV-infected patients were also positive for HEV markers (anti-HEV IgM and HEV RNA), while 63.2% of the patients were HAV mono-infected. Demographic and clinical criteria were comparable in both HAV mono-infected patients and HAV-HEV co-infected patients. Although liver enzymes were not significantly different between the two groups, liver transaminases were higher in the co-infected patients. Six patients developed acute liver failure (ALF); five of them were HAV-HEV-co-infected patients. The relative risk of ALF development was 8.5 times higher in HAV-HEV co-infection compared to mono-infection. Three cases of ALF caused by HAV-HEV co-infection were reported in children (below 18 years) and two cases were reported in adults. All patients developed jaundice, coagulopathy, and encephalopathy; all were living in rural communities. In conclusion: HAV-HEV co-infection can be complicated by ALF. The risk of ALF development in HAV-infected patients is higher when coinfection with HEV is present.