Serum concentrations of antiphospholipid and anticardiolipin antibodies are higher in HIV-infected women

Autoantibodies during infectious diseases: Lessons from malaria applied to COVID-19 and other infections

Autoimmunity is a common phenomenon reported in many globally relevant infections, including malaria and COVID-19. These and other highly inflammatory diseases have been associated with the presence of autoantibodies. The role that these autoantibodies play during infection has been an emerging topic of interest. The vast numbers of studies reporting a range of autoantibodies targeting cellular antigens, such as dsDNA and lipids, but also immune molecules, such as cytokines, during malaria, COVID-19 and other infections, underscore the importance that autoimmunity can play during infection. During both malaria and COVID-19, the presence of autoantibodies has been correlated with associated pathologies such as malarial anemia and severe COVID-19. Additionally, high levels of Atypical/Autoimmune B cells (ABCs and atypical B cells) have been observed in both diseases. The growing literature of autoimmune B cells, age-associated B cells and atypical B cells in Systemic Lupus erythematosus (SLE) and other autoimmune disorders has identified recent mechanistic and cellular targets that could explain the development of autoantibodies during infection. These new findings establish a link between immune responses during infection and autoimmune disorders, highlighting shared mechanistic insights. In this review, we focus on the recent evidence of autoantibody generation during malaria and other infectious diseases and their potential pathological role, exploring possible mechanisms that may explain the development of autoimmunity during infections.

The sexual dimorphism of anticardiolipin autoantibodies in acute Q fever patients

OBJECTIVES

Q fever is a zoonotic disease caused by Coxiella burnetii which affects men more than women (sex ratio men/women: 2.2). Acute Q fever complications are associated with elevation of anticardiolipin (aCL) antibodies. Here, we investigate the sexual dimorphism of aCL antibodies during acute C. burnetii infection.

METHODS

IgG aCL antibodies were evaluated at the time of Q fever serological diagnosis with enzyme-linked immunosorbent assay. Results were analysed according to sex.

RESULTS

Among the 1323 patients with Q fever tested for aCL, 1013 had acute Q fever (692 men/321 women) and 310 had persistent focalized infection (226 men/84 women). In cases of acute Q fever, men presented a significantly higher proportion of positive aCL antibodies (351/692, 50.7%) than women (113/321, 35.2%) (p <0.05). In addition, men had significantly higher aCL antibodies levels than women (p <0.001).

CONCLUSIONS

We highlight a relationship between sex and markers of autoimmunity during Q fever. Further investigations are necessary to better understand the mechanisms of this sexual dimorphism.

Clinical Features and Complications of Coxiella burnetii Infections From the French National Reference Center for Q Fever

IMPORTANCE

Q fever remains widespread throughout the world; the disease is serious and causes outbreaks and deaths when complications are not detected. The diagnosis of Q fever requires the demonstration of the presence of Coxiella burnetii and the identification of an organic lesion.

OBJECTIVE

To describe the hitherto neglected clinical characteristics of Q fever and identifying risk factors for complications and death.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study conducted from January 1, 1991, through December 31, 2016, included patients treated at the French National Reference Center for Q fever with serologic findings positive for C burnetii and clinical data consistent with C burnetii infection. Clinical data were prospectively collected by telephone. Patients with unavailable clinical data or an unidentified infectious focus were excluded.

MAIN OUTCOMES AND MEASURES

Q fever complications and mortality.

RESULTS

Of the 180 483 patients undergoing testing, 2918 had positive findings for C burnetii and 2434 (68.8% men) presented with clinical data consistent with a C burnetii infection. Mean (SD) age was 51.8 (17.4) years, and the ratio of men to women was 2.2. At the time of inclusion, 1806 patients presented with acute Q fever, including 138 with acute Q fever that progressed to persistent C burnetii infection, and 766 had persistent focalized C burnetii infection. Rare and hitherto neglected foci of infections included lymphadenitis (97 [4.0%]), acute Q fever endocarditis (50 [2.1%]), hemophagocytic syndrome (9 [0.4%]), and alithiasic cholecystitis (11 [0.4%]). Vascular infection (hazard ratio [HR], 3.1; 95% CI, 1.7-5.7; P < .001) and endocarditis (HR, 2.4; 95% CI, 1.1-5.1; P = .02) were associated with an increased risk of death. Independent indicators of lymphoma were lymphadenitis (HR, 77.4; 95% CI, 21.2-281.8; P < .001) and hemophagocytic syndrome (HR, 19.1; 95% CI, 3.4-108.6; P < .001). The presence of anticardiolipin antibodies during acute Q fever has been associated with several complications, including hepatitis, cholecystitis, endocarditis, thrombosis, hemophagocytic syndrome, meningitis, and progression to persistent endocarditis.

CONCLUSIONS AND RELEVANCE

Previously neglected foci of C burnetii infection include the lymphatic system (ie, bone marrow, lymphadenitis) with a risk of lymphoma. Cardiovascular infections were the main fatal complications, highlighting the importance of routine screening for valvular heart disease and vascular anomalies during acute Q fever. Routine screening for anticardiolopin antibodies during acute Q fever can help prevent complications. Positron emission tomographic scanning could be proposed for all patients with suspected persistent focused infection to rapidly diagnose vascular and lymphatic infections associated with death and lymphoma, respectively.

Study of Basic Coagulation Parameters among HIV Patients in Correlation to CD4 Counts and ART Status

INTRODUCTION

HIV infection is known to cause coagulation abnormalities by various mechanism, especially during its late course.

AIM

The objective of this study was to analyse platelet count, prothrombin time and activated partial thromboplastin time among HIV infected patients and to analyse these parameters with respect to their CD4 count and ART status.

MATERIALS AND METHODS

A case control study was conducted with 120 HIV infected patients and 40 normal individuals. The blood samples were collected after obtaining consent from the subjects. The blood samples were processed for platelet count, prothrombin time and activated partial thromboplastin time and CD4 count. The results were tabulated and analysed with statistical package.

RESULTS

The platelet count was significantly decreased in HIV infected patients compared to controls. Though HIV patients with CD4 count less than 200cells/mm(3) showed a decreased platelet count compared to those with CD4 count greater than 200cells/mm(3), it was not statistically significant. Prothrombin Time (PT) and Activated Partial Thromboplastin Time (aPTT) was significantly prolonged in HIV patients, but only aPTT showed significant inverse correlation with CD4 count. None of the parameters showed statistical significance on comparing HIV patients on ART with those not on ART.

CONCLUSION

Basic coagulation tests like platelet count, PT and especially aPTT can be used as prospective screening test to assess severity in HIV patients in resource limited settings where CD4 count is not available.

Autoimmune diseases in HIV-infected patients: 52 cases and literature review

OBJECTIVES

1) To describe autoimmune diseases (AD) in HIV-infected people; and 2) to perform a literature review concerning this issue.

DESIGN

52 HIV-infected patients that presented an AD in 14 medical departments in Paris and Ile-de-France area were retrospectively included in this study.

RESULTS

The ADs were vasculitis (11), immune cytopenias (8), rheumatic diseases (8), lupus (7), sarcoidosis (7), thyroid diseases (6), hepatic diseases (5), and antiphospholipid syndrome (4). Four patients presented 2 ADs. In 5 patients the AD preceded HIV infection, in 14 HIV infection was diagnosed at the same time as the AD and 34 were HIV-infected when they developed an AD. 40 ADs (80%) occurred in patients with a CD4 T lymphocyte count of more than 200/mm(3). Cases of autoimmune hemolytic anemia occurred only in patients severely immunodepressed. In five patients (a vasculitis case, a sarcoidosis case, three thyroid disease cases) the AD presented as a form of immune restoration inflammatory syndrome (IRIS). Some ADs allowed HIV-infection diagnosis at a stage of moderate immune deficiency (vasculitis, antiphospholipid syndrome, immune thrombocytopenia). 37 patients received immunosuppressant treatments with good tolerance. These results confirm in a large series of patients previous data concerning autoimmune diseases occurrence in HIV-infected people.

CONCLUSION

In the HAART era, when HIV-infected people are treated more and more early, autoimmune diseases can occur, mainly at the phase of immunological recovery. HIV infection should not limit immunosuppressant treatment use.