Anticardiolipin antibodies in chronic viral hepatitis. Do they have clinical consequences?

Impact of SARS-CoV-2 infection on the recovery of peripheral blood mononuclear cells by density gradient

SARS-CoV-2 virus infection is responsible for coronavirus disease (COVID-19), which is characterised by a hyperinflammatory response that plays a major role in determining the respiratory and immune-mediated complications of this condition. While isolating peripheral blood mononuclear cells (PBMCs) from whole blood of COVID-19 patients by density gradient centrifugation, we noticed some changes in the floating properties and in the sedimentation of the cells on density medium. Investigating this further, we found that in early phase COVID-19 patients, characterised by reduced circulating lymphocytes and monocytes, the PBMC fraction contained surprisingly high levels of neutrophils. Furthermore, the neutrophil population exhibited alterations in the cell size and in the internal complexity, consistent with the presence of low density neutrophils (LDNs) and immature forms, which may explain the shift seen in the floating abilities and that may be predictive of the severity of the disease. The percentage of this subset of neutrophils found in the PBMC band was rather spread (35.4 ± 27.2%, with a median 28.8% and IQR 11.6-56.1, Welch's t-test early phase COVID-19 versus blood donor healthy controls P < 0.0001). Results confirm the presence of an increased number of LDNs in patients with early stage COVID-19, which correlates with disease severity and may be recovered by centrifugation on a density gradient together with PBMCs.

Investigation of MicroRNA in Mitochondrial Apoptotic Pathway in Systemic Lupus Erythematosus

Background

Accumulating evidence indicates that microRNAs play a pivotal role in the pathogenesis of systemic lupus erythematosus (SLE). This study tested the hypothesis that microRNA is associated with the mitochondrial apoptotic pathway in patients with SLE.

Methods

Thirteen patients were in the clinical comparison study and microRNA study and overall 19 patients in the study of intracellular protein. Levels of microRNAs were determined by miRNeasy kit in 13 patients with SLE and 29 volunteer normal controls. Intracellular levels of caspase-9, caspase-10, MAVS, MDA5, and pIRF7 in mononuclear cells from 19 patiens and the SLE disease activity index (SLEDAI) were determined in all SLE patients. Correlation analyses were performed among microRNAs, intracellular adaptor proteins, and caspase levels and mean SLEDAI.

Results

The ΔCT, defined by test reading difference between the target and the internal control microRNA (miR-451a), of miR-21-5p, miR-150-5p, and miR221-3p were significantly higher in plasma from SLE patients than in normal controls. miR-150-5pΔCT was positively correlated with both CRP and SLEDAI value. miR-150-5pΔCT was negatively associated with MAVS 70 kD. Caspase-10 protein levels were negatively associated with plasma miR-22-3pΔCT and miR-21-5pΔCT levels.

Conclusions

Our study confirmed the hypothesis that these microRNAs were associated with the mitochondrial apoptotic pathway in SLE. miR-150-5pΔCT was positively associated with SLE disease activity and it was negatively correlated with MAVS 70 kD, which may facilitate viral survival and further enhance inflammation. On the other hand, miR-22-3pΔCT and miR-21-5pΔCT, were negatively correlated with caspase-10 levels, which may repress extrinsic apoptosis and increase cell survival.

The environment and antiphospholipid syndrome

The etiology of autoimmune diseases is multifactorial. The degree to which genetic and environmental factors influence susceptibility to autoimmune diseases is poorly defined. It is believed that versatile clinical presentations of autoimmune diseases stem from various combinations of the genetic and environmental factors. One of the newly diagnosed autoimmune diseases is the antiphospholipid syndrome (APS). APS is characterized by vascular thrombosis, and/or pregnancy morbidity associated with anticardiolipin (aCL), anti-β2-glycoprotein-I (anti-β2GPI) and lupus anticoagulant (LAC).

Associations of antiphospholipid antibodies with splanchnic vein thrombosis: a systematic review with meta-analysis

Splanchnic vein thrombosis (SVT) refers to Budd-Chiari syndrome (BCS) and portal vein system thrombosis (PVST). Current practice guidelines have recommended the routine screening for antiphospholipid antibodies (APAs) in patients with SVT. A systematic review and meta-analysis of observational studies was performed to explore the association between APAs and SVT. The PubMed, EMBASE, and ScienceDirect databases were searched for all relevant papers, in which the prevalence of positive APAs or levels of APAs should be compared between BCS or noncirrhotic PVST patients versus healthy controls, or between cirrhotic patients with portal vein thrombosis (PVT) versus those without PVT. Fourteen studies were eligible. Only 1 study evaluated the role of APAs in BCS patients and found that positive immunoglobulin (Ig) G anticardiolipin antibody (aCL) was more frequently observed in BCS patients than in healthy controls; however, the associations of other APAs with BCS were not evaluated. Positive IgG aCL was more frequently observed in noncirrhotic patients with PVST than in healthy controls; however, other APAs, such as IgM aCL, lupus anticoagulants (LAs), anti-β2-glycoprotein-I antibody (aβ2GPI), and aβ2GPI-oxidized low-density lipoprotein antibody (ox-LDL) were not associated with noncirrhotic PVST. Positive unclassified aCL was more frequently observed in cirrhotic patients with PVT than in those without PVT; however, the association of IgG aCL and IgM aCL with the development of PVT in liver cirrhosis remained inconsistent among studies. The risk of BCS and noncirrhotic PVST might be increased by positive IgG aCL but not IgM aCL, LA, aβ2GPI, or aβ2GPI ox-LDL. However, the evidence regarding APAs in BCS originated from only 1 study. The association between APAs and PVT in liver cirrhosis was unclear.

Immune Components of Liver Damage Associated with Connective Tissue Diseases

Autoimmune connective tissue diseases are associated with liver abnormalities and often have overlapping pathological and clinical manifestations. As a result, they can present great clinical challenges and evoke questions about diagnostic criteria for liver diseases. Moreover, discriminating between liver involvement as a manifestation of connective tissue disease and primary liver disease can be challenging since they share a similar immunological mechanism. Most patients with connective tissue diseases exhibit liver test abnormalities that likely result from coexisting, primary liver diseases, such as fatty liver disease, viral hepatitis, primary biliary cirrhosis, autoimmune hepatitis, and drug-related liver toxicity. Liver damage can be progressive, leading to cirrhosis, complications of portal hypertension, and liver-related death, and, therefore, must be accurately identified. In this review, we highlight the challenges facing the diagnosis of liver damage associated with connective tissue disease and identify immune mechanisms involved in liver damage associated with connective tissue diseases.

Review: Viral infections and mechanisms of thrombosis and bleeding

Viral infections are associated with coagulation disorders. All aspects of the coagulation cascade, primary hemostasis, coagulation, and fibrinolysis, can be affected. As a consequence, thrombosis and disseminated intravascular coagulation, hemorrhage, or both, may occur. Investigation of coagulation disorders as a consequence of different viral infections have not been performed uniformly. Common pathways are therefore not fully elucidated. In many severe viral infections there is no treatment other than supportive measures. A better understanding of the pathophysiology behind the association of viral infections and coagulation disorders is crucial for developing therapeutic strategies. This is of special importance in case of severe complications, such as those seen in hemorrhagic viral infections, the incidence of which is increasing worldwide. To date, only a few promising targets have been discovered, meaning the implementation in a clinical context is still hampered. This review discusses non‐hemorrhagic and hemorrhagic viruses for which sufficient data on the association with hemostasis and related clinical features is available. This will enable clinicians to interpret research data and place them into a perspective. J. Med. Virol. 84:1680–1696, 2012. © 2012 Wiley Periodicals, Inc.

Andes virus antigens are shed in urine of patients with acute hantavirus cardiopulmonary syndrome

Hantavirus cardiopulmonary syndrome (HCPS) is a highly pathogenic emerging disease (40% case fatality rate) caused by New World hantaviruses. Hantavirus infections are transmitted to humans mainly by inhalation of virus-contaminated aerosol particles of rodent excreta and secretions. At present, there are no antiviral drugs or immunotherapeutic agents available for the treatment of hantaviral infection, and the survival rates for infected patients hinge largely on early virus recognition and hospital admission and aggressive pulmonary and hemodynamic support. In this study, we show that Andes virus (ANDV) interacts with human apolipoprotein H (ApoH) and that ApoH-coated magnetic beads or ApoH-coated enzyme-linked immunosorbent assay plates can be used to capture and concentrate the virus from complex biological mixtures, such as serum and urine, allowing it to be detected by both immunological and molecular approaches. In addition, we report that ANDV-antigens and infectious virus are shed in urine of HCPS patients.

Antiphospholipid antibodies in HIV-positive patients

Antiphospholipid (aPL) antibodies classically have been associated with thrombotic phenomena and abortion in patients with autoimmune diseases. The objective of the present work was to evaluate the frequency of such antibodies in patients infected with HIV and study its association with the presence of clinical manifestations of antiphospholipid syndrome (APS). Using a transversal study, a population of patients diagnosed with HIV, identified through an enzyme-linked immunosorbent assay (ELISA) test and confirmed by Western blotting, aged above 17 years old, was investigated. Through a standard questionnaire, the presence of APS manifestations was investigated, as well as the frequency of rheumatic manifestations. Antibodies against beta2 glycoprotein I (anti-beta2 GPI) and anticardiolipin (aCL) IgA, IgG, and IgM were investigated by the ELISA method using commercial kits (QUANTA Lite, INOVA Diagnostics). Ninety patients were studied, 47 (52.2%) male and 43 (47.8%) female. Clinical manifestations of APS were detected in 12 patients (13.3%) of the studied population, whereas arthralgia was the most common rheumatic manifestation (38.9%). Of the 90 patients, 40 (44.4%) were reactive for at least one type of aPL antibody (aCL and/or anti-beta2 GPI). The frequency of aCL was 17.8%, from which 15 (16.7%) had aCL IgG, 3 (3.3%) IgM, and 1 (1.1%) IgA. The frequency of the anti-beta2 GPI antibody was 33.3%, from which 29 (32.2%) were positive for isotype IgA, 4 (4.4%) isotype IgM, and 1 (1.1%) isotype IgG. No association was observed between immunoreactivity for aPL antibodies in general or each isotype in particular and the presence of APS manifestation. In the present study, it was possible to observe a relatively high frequency of aPL antibodies, particularly for isotype IgA anti-beta2 GPI in HIV. However, there was no association to APS manifestations, suggesting that such antibodies had no etiopathogenic role in these complications in patients with such retroviral infection.

Do antiphospholipid antibodies develop for a purpose?

There is a growing body of literature suggesting that antiphospholipid antibodies develop for a purpose, that they play several key roles in the innate immune response, and are only rendered pathologic in susceptible people under adverse intravascular conditions. This paper will review evidence that the autoantibodies associated with the antiphospholipid syndrome develop from natural autoantibodies for purposes that are beneficial to host defense, and are only rendered pathologic as a result of adverse intravascular events.

Presence of high avidity anticardiolipin antibodies in patients with autoimmune cholestatic liver diseases

We studied the prevalence and clinical significance of anticardiolipin antibodies (aCL) in primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) as similar data are missing. Ninety-nine PBC patients, 41 PSC, 228 HCV, 50 HBV, 111 with other non-viral and non-autoimmune liver disorders and 267 healthy were investigated. In order to evaluate the avidity of aCL, urea 2 M was used. IgG and/or IgM aCL were detected in 40% of PBC and PSC patients, in 26.2% of disease controls (P < 0.05) and 2.25% of healthy (P < 0.05). In PBC, IgG aCL associated with presence of cirrhosis, increased Mayo risk score and thrombocytopenia, while in PSC with longer disease duration and biochemical activity. Anti-beta2-GPI was detected in only three patients. Both in PBC and PSC, resistance of aCL to urea was high, similar to that observed in antiphospholipid syndrome (APS). We demonstrated a significantly higher prevalence of aCL in PBC and PSC compared to other liver diseases and healthy. aCL were associated with more severe disease in PBC and biochemical activity in PSC, but they rather seem to be "non-pathogenic" (co-factor-independent). However, their avidity was comparable with that of APS, indicating the need for prospective studies in order to address whether aCL in PBC and PSC may contribute to APS development or the progression of hepatic disease.

Manifestaciones extrahepáticas de la infección por el virus de la hepatitis C

Hepatitis C virus predominantly affects the liver, although it may also produce a number of extrahepatic manifestations, such as mixed cryoglobulinemia, salivary and lacrimal gland dysfunction, and several types of kidney disease. The pathogenesis of these conditions is not completely understood, but immunologic mechanisms are involved in many cases. In some patients with hepatitis C virus infection, the extrahepatic manifestations predominate and their proper diagnosis and management is very important.