Effects of human immunodeficiency virus on the erythrocyte and megakaryocyte lineages

Mechanisms and Cardiorenal Complications of Chronic Anemia in People with HIV

Chronic anemia is more prevalent in people living with HIV (PLWH) compared to the general population. The mechanisms that drive chronic anemia in HIV are multifaceted and include functional impairment of hematopoietic stem cells, dysregulation of erythropoietin production, and persistent immune activation. Chronic inflammation from HIV infection adversely affects erythropoiesis, erythrocyte lifespan, and erythropoietin response, leading to a heightened risk of co-infections such as tuberculosis, persistent severe anemia, and increased mortality. Additionally, chronic anemia exacerbates the progression of HIV-associated nephrotoxicity and contributes to cardiovascular risk through immune activation and inflammation. This review highlights the cardinal role of chronic inflammation as a link connecting persistent anemia and cardiovascular complications in PLWH, emphasizing the need for a universal understanding of these interconnected pathways for targeted interventions.

Anemia, iron, and HIV: decoding the interconnected pathways: A review

This review delves into the intricate relationship between anemia, iron metabolism, and human immunodeficiency virus (HIV), aiming to unravel the interconnected pathways that contribute to the complex interplay between these 3 entities. A systematic exploration of relevant literature was conducted, encompassing studies examining the association between anemia, iron status, and HIV infection. Both clinical and preclinical investigations were analyzed to elucidate the underlying mechanisms linking these components. Chronic inflammation, a hallmark of HIV infection, disrupts iron homeostasis, impacting erythropoiesis and contributing to anemia. Direct viral effects on bone marrow function further compound red blood cell deficiencies. Antiretroviral therapy, while essential for managing HIV, introduces potential complications, including medication-induced anemia. Dysregulation of iron levels in different tissues adds complexity to the intricate network of interactions. Effective management of anemia in HIV necessitates a multifaceted approach. Optimization of antiretroviral therapy, treatment of opportunistic infections, and targeted nutritional interventions, including iron supplementation, are integral components. However, challenges persist in understanding the specific molecular mechanisms governing these interconnected pathways. Decoding the interconnected pathways of anemia, iron metabolism, and HIV is imperative for enhancing the holistic care of individuals with HIV/AIDS. A nuanced understanding of these relationships will inform the development of more precise interventions, optimizing the management of anemia in this population. Future research endeavors should focus on elucidating the intricate molecular mechanisms, paving the way for innovative therapeutic strategies in the context of HIV-associated anemia.

Prevalence of Cytopenia and its Correlation with Immunosuppression in Naïve HIV-1 Infected Patients Initiating First-Line Antiretroviral Therapy: A Pilot Study

BACKGROUND

Cytopenias serve as common indicators and crucial predictive tools for evaluating disease progression and therapeutic outcomes in individuals with human immunodeficiency virus (HIV) infection. This study aimed to assess the prevalence of cytopenias and their correlation with the level of immunosuppression in treatment-naive HIV-infected participants after initiating highly active combined antiretroviral drug therapy (cART24).

MATERIALS AND METHODS

This prospective study focused on evaluating cytopenia in 44 treatment-naive HIV-infected patients who consented to initiate cART and were consecutively enrolled. The research was conducted at the Nasara HIV Treatment & Care Centre of Ahmadu Bello University Teaching Hospital (ABUTH), Zaria, Nigeria, spanning from December 2016 to January 2018. Cytopenias, including anemia, leucopenia, lymphocytopenia, and thrombocytopenia, were defined and assessed according to World Health Organization guidelines. A combination of cross-sectional and longitudinal mixed-design two-step analysis was employed to validate our findings.

RESULTS

The median time from enrollment to cART initiation was 7 days, following the universal test and treat protocol. The prevalence of cytopenia was 75% at the baseline before treatment and increased to 84% after cART24 administration. There were no statistically significant differences in the median values of immuno-hematological parameters between baseline and after cART24 initiation (P >0.05). In terms of longitudinal assessment, the prevalence of anemia, leucopenia, lymphopenia, and thrombocytopenia at baseline were 66%, 23%, 0%, and 11%, respectively, and after cART24, the rates were 66%, 29%, 5%, and 20%. Notably, the prevalence of cytopenia correlated with declining CD4+ T cell counts. Among instances of unicytopenia, 58% exhibited isolated anemia, 6% had lone leucopenia, and 6% had solitary thrombocytopenia. Additionally, 27% demonstrated bi-cytopenia, and 3% exhibited pancytopenia. Interestingly, none of the study participants presented with lymphopenia. The most common combination was anemia and thrombocytopenia. Both longitudinal and cross-sectional analytical findings were consistent.

CONCLUSION

In treatment-naive HIV-infected individuals, the prevalence of cytopenias, particularly anemia and thrombocytopenia, was substantial and correlated with the degree of immunosuppression as indicated by CD4+ T cell counts. These cytopenias persisted despite initiation of cART24, highlighting the complexity of hematological manifestations in HIV infection. Our study underscores the significant hematopathological impact of HIV and antiretroviral therapy, highlighting the necessity for preventive strategies to mitigate these adverse effects.

Co-Occurrence of G6PD Deficiency and SCT among Pregnant Women Exposed to Infectious Diseases

During pregnancy, women have an increased relative risk of exposure to infectious diseases. This study was designed to assess the prevalence of the co-occurrence of glucose-6-phosphate dehydrogenase deficiency (G6PDd) and sickle cell trait (SCT) and the impact on anemia outcomes among pregnant women exposed to frequent infectious diseases. Over a six-year period (March 2013 to October 2019), 8473 pregnant women attending antenatal clinics (ANCs) at major referral hospitals in Northern Ghana were recruited and diagnosed for common infectious diseases (malaria, syphilis, hepatitis B, and HIV), G6PDd, and SCT. The prevalence of all the infections and anemia did not differ between women with and without G6PDd (χ2 < 3.6, p > 0.05 for all comparisons). Regression analysis revealed a significantly higher proportion of SCT in pregnant women with G6PDd than those without G6PDd (AOR = 1.58; p < 0.011). The interaction between malaria and SCT was observed to be associated with anemia outcomes among the G6PDd women (F-statistic = 10.9, p < 0.001). Our findings show that anemia is a common condition among G6PDd women attending ANCs in northern Ghana, and its outcome is impacted by malaria and SCT. This warrants further studies to understand the impact of antimalarial treatment and the blood transfusion outcomes in G6PDd/SCT pregnant women.

Risk factors and prognosis of thrombocytopenia in people living with HIV/AIDS

Background

Thrombocytopenia is a common hematological manifestation in people living with human immunodeficiency virus (HIV) or acquired immune deficiency syndrome (AIDS; PLWHA). Data on the prognostic relationship and associated factors of thrombocytopenia and HIV infection in China are limited.

Objectives

We assessed the prevalence of thrombocytopenia, its association with prognosis, and analyzed the associated risk factors among demographic characteristics, comorbidities, hematological and bone marrow indicators.

Design

We collected patients identified as PLWHA in Zhongnan Hospital. The patients were divided into two groups: the thrombocytopenia group and the non-thrombocytopenia group. We analyzed and compared demographic characteristics, comorbidities, peripheral blood cells, lymphocyte subpopulations, infection indicators, bone marrow cytology, and bone marrow morphology of the two groups. Then we analyzed the risk factors for thrombocytopenia and the effect of platelet (PLT) values on the prognosis of patients.

Methods

Demographic characteristics and laboratory results were obtained from medical records. In contrast to other studies, we included bone marrow cytology and morphology in this study. Data were analyzed with multivariate logistic regression analysis. The Kaplan-Meier method was used to plot 60-month survival curves for the severe, mild, and non-thrombocytopenia groups. The value p < 0.05 was taken as statistically significant.

Results

Among 618 identified PLWHA, 510 (82.5%) were male. Overall, thrombocytopenia was found in 37.7% [95% confidence interval (CI): 33.9-41.5%]. Multivariable logistic regression analysis showed that age ⩾40 years [adjusted odds ratio (AOR) 1.869, 95% CI: 1.052-3.320], combined with hepatitis B (AOR 2.004, 95% CI: 1.049-3.826), high procalcitonin (PCT) count (AOR 1.038, 95% CI: 1.000-1.078) were risk factors of thrombocytopenia in PLWHA. An increased percentage of thrombocytogenic megakaryocytes was a protective factor, with an AOR 0.949 (95% CI: 0.930-0.967). Kaplan-Meier survival curve analysis showed that the prognosis was worse in the severe than in the mild (p = 0.002) and non-thrombocytopenia groups (p = 0.008).

Conclusion

We discovered a general high pervasiveness of thrombocytopenia in PLWHA in China. Age ⩾40 years, combined with hepatitis B virus infection, high PCT, and decreased percentage of thrombocytogenic megakaryocytes indicated a higher risk for developing thrombocytopenia. A PLT count ⩽50 × 109/liter led to a worse prognosis. Therefore, early diagnosis and treatment of thrombocytopenia in these patients are useful.

SARS-CoV-2 Lysate Stimulation Impairs the Release of Platelet-like Particles and Megakaryopoiesis in the MEG-01 Cell Line

SARS-CoV-2 infection causes a considerable inflammatory response coupled with impaired platelet reactivity, which can lead to platelet disorders recognized as negative prognostic factors in COVID-19 patients. The virus may cause thrombocytopenia or thrombocytosis during the different disease stages by destroying or activating platelets and influencing platelet production. While it is known that several viruses can impair megakaryopoiesis by generating an improper production and activation of platelets, the potential involvement of SARS-CoV-2 in affecting megakaryopoiesis is poorly understood. To this purpose, we explored, in vitro, the impact of SARS-CoV-2 stimulation in the MEG-01 cell line, a human megakaryoblastic leukemia cell line, considering its spontaneous capacity of releasing platelet-like particles (PLPs). We interrogated the effect of heat-inactivated SARS-CoV-2 lysate in the release of PLPs and activation from MEG-01, the signaling pathway influenced by SARS-CoV-2, and the functional effect on macrophagic skewing. The results highlight the potential influence of SARS-CoV-2 in the early stages of megakaryopoiesis by enhancing the production and activation of platelets, very likely due to the impairment of STATs signaling and AMPK activity. Overall, these findings provide new insight into the role of SARS-CoV-2 in affecting megakaryocyte-platelet compartment, possibly unlocking another avenue by which SARS-CoV-2 moves.

Anemia and opportunistic infections in hospitalized people living with HIV: a retrospective study

BACKGROUND

There is a high prevalence of anemia among people living with HIV in Guangxi, China. Therefore, we investigated anemia and opportunistic infections in hospitalized people living with HIV and explored the risk factors related to anemia in people living with HIV to actively prevent anemia in people living with HIV.

METHODS

We retrospectively studied people living with HIV admitted to Guangxi Chest Hospital from June 2016 to October 2021. Detailed information on the sociodemographic and clinical features of the participants was collected. The X² test was used to compare the prevalence between the anemic and non-anemic groups. The logistic regression analysis was applied to exclude confounding factors and identify factors related to anemia.

RESULTS

Among 5645 patients with HIV, 1525 (27.02%) had anemia. The overall prevalence of mild, moderate, and severe anemia was 4.66%, 14.08%, and 8.27%, respectively. The factors significantly related to increased risk of anemia were CD4 count < 50 cells/µl (aOR = 2.221, 95% CI = [1.775, 2.779]), CD4 count 50-199 cells/µl (aOR = 1.659, 95% CI = [1.327, 2. 073]), female (aOR = 1.644, 95% CI = [1.436, 1.881]) co-infected with HCV (aOR = 1.465, 95% CI = [1.071, 2.002]), PM (aOR = 2.356, 95% CI = [1.950, 2.849]), or TB (aOR = 1.198, 95% CI = [1.053, 1.365]).

CONCLUSIONS

Within Guangxi of China, 27.02% of hospitalized people living with HIV presented with anemia. Most patients with anemia were in the mild to moderate stage. The low CD4 count, female gender, and concomitant infection with Penicillium marneffei, Hepatitis C virus, or Tuberculosis were independent correlates of anemia. Thus, these findings would be helpful to clinicians in preventing and intervening in anemia in people living with HIV.

Increased platelet activation and platelet-inflammasome engagement during chikungunya infection

Chikungunya fever is a viral disease transmitted by mosquitoes of the genus Aedes. The infection is usually symptomatic and most common symptoms are fever accompanied by joint pain and swelling. In most cases symptoms subside within a week. However, severe prolonged and disabling joint pain, that may persist for several months, even years, are reported. Although the pathogenesis of Chikungunya infection is not fully understood, the evolution to severe disease seems to be associated with the activation of immune mechanisms and the action of inflammatory mediators. Platelets are recognized as inflammatory cells with fundamental activities in the immune response, maintenance of vascular stability and pathogenicity of several inflammatory and infectious diseases. Although the involvement of platelets in the pathogenesis of viral diseases has gained attention in recent years, their activation in Chikungunya has not been explored. The aim of this study was to analyze platelet activation and the possible role of platelets in the amplification of the inflammatory response during Chikungunya infection. We prospectively included 132 patients attended at the Quinta D’Or hospital and 25 healthy volunteers during the 2016 epidemic in Rio de Janeiro, Brazil. We observed increased expression of CD62P on the surface of platelets, as well as increased plasma levels of CD62P and platelet-derived inflammatory mediators indicating that the Chikungunya infection leads to platelet activation. In addition, platelets from chikungunya patients exhibit increased expression of NLRP3, caspase 4, and cleaved IL-1β, suggestive of platelet-inflammasome engagement during chikungunya infection. In vitro experiments confirmed that the Chikungunya virus directly activates platelets. Moreover, we observed that platelet activation and soluble p-selectin at the onset of symptoms were associated with development of chronic forms of the disease. Collectively, our data suggest platelet involvement in the immune processes and inflammatory amplification triggered by the infection.

HIV infection is not associated with perioperative blood loss in patients undergoing total hip arthroplasty

Background

Patients with HIV have a higher prevalence of thrombocytopenia than those without HIV infection, increasing their risk of substantial perioperative blood loss (PBL) during total hip arthroplasty (THA). This study aimed to evaluate PBL risk factors in HIV-infected patients undergoing THA.

Methods

Eighteen HIV+ patients (21 hip joints) and 33 HIV− patients (36 joints) undergoing THA were enrolled in this study. PBL was calculated using the Gross equation, which comprises total blood loss (TBL), dominant blood loss (DBL), and hidden blood loss (HBL). Risk factors for post-THA PBL in both patient populations was evaluated using multivariable linear regression.

Results

At baseline, the HIV+ patients were younger, more likely to be male and to have elevated hemoglobin and albumin levels, and lower erythrocyte sedimentation rates than HIV− patients. There were no differences in the T-lymphocyte subsets or coagulation function between the two groups. Age and albumin level were identified as potential HBL risk factors after THA, and albumin level was associated with higher TBL. The unadjusted linear regression analysis showed that the HBL and TBL were significantly higher in HIV+ patients than in HIV− patients. However, after adjusting for other factors, no differences in DBL, HBL, or TBL were observed between HIV− and HIV+ patients.

Conclusion

PBL was similar in both groups undergoing THA, regardless of their HIV-infection status. THA surgery is a safe and effective procedure in HIV+ patients.

Incidence and predictors of anemia among adults on HIV care at South Gondar Zone Public General Hospital Northwest Ethiopia, 2020; retrospective cohort study

BACKGROUND

Anemia is a major public health problem worldwide which accounts 24.8% of the population. Subsequently, anemia is a leading killer of people living with human immunodeficiency virus and many of these deaths occur in developing countries including Ethiopia. Cross sectional studies have done on anemia and human immunodeficiency virus. However, there is limited study on incidence of anemia and its predictors among adults on HIV care, especially no survival study has been conducted in the study area.

OBJECTIVE

To assess incidence and predictors of anemia among adults on Human immunodeficiency virus care.

METHODS

An institution-based retrospective cohort study was conducted among 434 adults on HIV care from January 1st 2015 to December 30th 2019 at Debre Tabor Referral Hospital. A computer-generated simple random sampling technique was employed to select the study participants. Ethical clearance was obtained from the Institutional Review Board of Bahir Dar University, and also, we got implied consent to review charts from the concerned bodies in the hospital. Data were entered using Epi-data version 3.1 and analyzed by using STATA version 14.0. A Kaplan Meier survival curve was utilized to estimate anemia free survival time. Bivariable and Multivariable Cox proportional hazards model were fitted to identify predictors of anemia.

RESULTS

The overall incidence density rate of anemia was 6.27 (95% CI: 0.051, 0.077) per 100 person years. Clinical stage III/IV (AHR = 1.04; 95% CI = 1.02, 1.06), Body Mass Index less than 18.5 kg/m2 (AHR = 3.11; 95% CI = 1.56, 6.22), serum creatinine greater than 1.1 IU/L(AHR = 2.07; 95% CI = 1.12, 3.81) and fair/poor level of adherence(AHR = 1.05; 95% CI = 1.03, 1.07) were statistically significant predictors of anemia while increased anti-retroviral treatment duration (AHR = 0.98; 95% CI = 0.97, 0.99) decrease the risk of anemia at 95% confidence level.

CONCLUSION

The overall incidence density rate of anemia was high. Patients with clinical stage III/IV, body mass index < 18.5 kg/m2, serum creatinine greater than 1.1 IU/L and fair/poor level of adherence were significant predictors of anemia while increased antiretroviral treatment duration had decreased the risk of anemia.

RECOMMENDATION

Even if the overall incidence rate of anemia was lower as compared to previous studies in Ethiopia, still the incidence of anemia was high. So, prevention measures should be taken beside with HIV care especially within 6-months ART initiation.

Anemia and thrombocytopenia in people living with HIV/AIDS: a narrative literature review

Hematologic changes are frequent complications in people living with HIV/AIDS (PLWHA). Anemia and thrombocytopenia are the most frequent multifactorial hematologic abnormalities and are associated with a low quality of life and high death rates. This study aims to describe the prevalence of anemia and thrombocytopenia in PLWHA and to identify the main clinical characteristics that aggravate these conditions in studies published in the last 10 y. A comprehensive search was performed on the PUBMED database, using the terms ‘HIV infection and anemia’ and ‘HIV infection and thrombocytopenia’. Additional searches were made in the reference lists of articles covering the theme. The selected studies reported an overall prevalence of anemia from 7.2% to 84% and of thrombocytopenia from 4.5% to 26.2%. The prevalence of thrombocytopenia and anemia were aggravated by a CD4⁺ T lymphocyte count of <200 cells/μL, increased viral load and coinfections or opportunistic infections. Antiviral therapy (ART) shows a beneficial effect, reducing the frequencies of thrombocytopenia and anemia, except in a zidovudine-based ART regimen, which worsens the anemic condition. Because anemia and thrombocytopenia are treatable comorbidities associated with increased mortality among PLWHA, physicians should monitor these risk factors in order to establish better interventions and reduce morbidity and mortality in PLWHA.

High Prevalence of Anemia among Human Immunodeficiency Virus-Infected Patients: A Cross-sectional Study in Bali-Indonesia

Anemia is a common condition found among Human Immunodeficiency Virus (HIV)-infected patients. T-cells that are infected with HIV virus can directly suppress the growth of progenitor cells in the bone marrow so that affecting the hemopoiesis resulted in anemia. These hematological abnormalities could potentially cause serious clinical implications. This study was conducted to determine the prevalence of anemia in HIV-infected patients in Bali. It was ahospital based cross-sectional studyconducted at two public hospital in Bali-Indonesia. A total of 243 medical record data from HIV-infected patients atWangaya Hospital Denpasar Bali and Sanjiwani Hospital Gianyar Bali between 2009 -2017 were included in analysis. Prevalence of anemia in antiretroviral (ART)-naïve patients and in patients on ART were 60.8% and 40.3%, respectively. Leucopenia and thrombocytopenia were found 8.2% and 9.4%, respectively, in ART-naïve group. While in patients with ART group leucopenia and thrombocytopenia were accounted for 6.9% and 4.3%, respectively. There was a significant difference in prevalence of anemia between ART-naïve patients and patients on ART (60.8% vs. 40.3%; p < 0.05). Although the prevalence of anemia was lower in patients on ART, but anemia continues to be common in a substantial portion of HIV-infected persons. Another studies are still needed to addressing the impact of anemia on HIV-infected individuals, as well as treatment strategies and future research directions.

Human Immunodeficiency Virus Infection and Diverse Physical Health Outcomes: An Umbrella Review of Meta-analyses of Observational Studies

Background

Our aim was to assess both the credibility and strength of evidence arising from systematic reviews with meta-analyses of observational studies and physical health outcomes associated with human immunodeficiency virus (HIV) but not acquired immunodeficiency syndrome.

Methods

We performed an umbrella review of observational studies. Evidence was graded as convincing, highly suggestive, suggestive, weak, or nonsignificant.

Results

From 3413 studies returned, 20 were included, covering 55 health outcomes. Median number of participants was 18 743 (range 403–225 000 000). Overall, 45 (81.8%) of the 55 unique outcomes reported nominally significant summary results (P < .05). Only 5 outcomes (9.0%; higher likelihood of presence of breathlessness, higher chronic obstructive pulmonary disease [COPD] prevalence, maternal sepsis, higher risk of anemia, and higher risk of all fractures among people living with HIV [PLWHIV]) showed suggestive evidence, with P values < 10^–3; only 3 (5.5%; higher prevalence of cough in cross-sectional studies, higher incidence of pregnancy-related mortality, and higher incidence of ischemic heart disease among PLWHIV in cohort studies) outcomes showed stronger evidence using a stringent P value (<10^–6). None of the unique outcomes presented convincing evidence (Class I), yet 3 outcomes presented highly suggestive evidence, 5 outcomes presented suggestive evidence, and 37 outcomes presented weak evidence.

Conclusions

Results show highly suggestive and suggestive evidence for HIV and the presence of a cough, COPD, ischemic heart disease, pregnancy-related mortality, maternal sepsis, and bone fractures. Public health policies should reflect and accommodate these changes, especially in light of the increases in the life expectancy and the incidence of comorbidities in this population.

Risk scores for predicting early antiretroviral therapy mortality in sub-Saharan Africa to inform who needs intensification of care: a derivation and external validation cohort study

BACKGROUND

Clinical scores to determine early (6-month) antiretroviral therapy (ART) mortality risk have not been developed for sub-Saharan Africa (SSA), home to 70% of people living with HIV. In the absence of validated scores, WHO eligibility criteria (EC) for ART care intensification are CD4 < 200/μL or WHO stage III/IV.

METHODS

We used Botswana XPRES trial data for adult ART enrollees to develop CD4-independent and CD4-dependent multivariable prognostic models for 6-month mortality. Scores were derived by rescaling coefficients. Scores were developed using the first 50% of XPRES ART enrollees, and their accuracy validated internally and externally using South African TB Fast Track (TBFT) trial data. Predictive accuracy was compared between scores and WHO EC.

RESULTS

Among 5553 XPRES enrollees, 2838 were included in the derivation dataset; 68% were female and 83 (3%) died by 6 months. Among 1077 TBFT ART enrollees, 55% were female and 6% died by 6 months. Factors predictive of 6-month mortality in the derivation dataset at p < 0.01 and selected for the CD4-independent score included male gender (2 points), ≥ 1 WHO tuberculosis symptom (2 points), WHO stage III/IV (2 points), severe anemia (hemoglobin < 8 g/dL) (3 points), and temperature > 37.5 °C (2 points). The same variables plus CD4 < 200/μL (1 point) were included in the CD4-dependent score. Among XPRES enrollees, a CD4-independent score of ≥ 4 would provide 86% sensitivity and 66% specificity, whereas WHO EC would provide 83% sensitivity and 58% specificity. If WHO stage alone was used, sensitivity was 48% and specificity 89%. Among TBFT enrollees, the CD4-independent score of ≥ 4 would provide 95% sensitivity and 27% specificity, whereas WHO EC would provide 100% sensitivity but 0% specificity. Accuracy was similar between CD4-independent and CD4-dependent scores. Categorizing CD4-independent scores into low (< 4), moderate (4-6), and high risk (≥ 7) gave 6-month mortality of 1%, 4%, and 17% for XPRES and 1%, 5%, and 30% for TBFT enrollees.

CONCLUSIONS

Sensitivity of the CD4-independent score was nearly twice that of WHO stage in predicting 6-month mortality and could be used in settings lacking CD4 testing to inform ART care intensification. The CD4-dependent score improved specificity versus WHO EC. Both scores should be considered for scale-up in SSA.

Crosstalk Between Platelets and Microbial Pathogens

Platelets, small anucleate cells circulating in the blood, are critical mediators in haemostasis and thrombosis. Interestingly, recent studies demonstrated that platelets contain both pro-inflammatory and anti-inflammatory molecules, equipping platelets with immunoregulatory function in both innate and adaptive immunity. In the context of infectious diseases, platelets are involved in early detection of invading microorganisms and are actively recruited to sites of infection. Platelets exert their effects on microbial pathogens either by direct binding to eliminate or restrict dissemination, or by shaping the subsequent host immune response. Reciprocally, many invading microbial pathogens can directly or indirectly target host platelets, altering platelet count or/and function. In addition, microbial pathogens can impact the host auto- and alloimmune responses to platelet antigens in several immune-mediated diseases, such as immune thrombocytopenia, and fetal and neonatal alloimmune thrombocytopenia. In this review, we discuss the mechanisms that contribute to the bidirectional interactions between platelets and various microbial pathogens, and how these interactions hold relevant implications in the pathogenesis of many infectious diseases. The knowledge obtained from "well-studied" microbes may also help us understand the pathogenesis of emerging microbes, such as SARS-CoV-2 coronavirus.

Human megakaryocytes possess intrinsic antiviral immunity through regulated induction of IFITM3

Evolving evidence indicates that platelets and megakaryocytes (MKs) have unexpected activities in inflammation and infection; whether viral infections upregulate biologically active, antiviral immune genes in platelets and MKs is unknown, however. We examined antiviral immune genes in these cells in dengue and influenza infections, viruses that are global public health threats. Using complementary biochemical, pharmacological, and genetic approaches, we examined the regulation and function of interferon-induced transmembrane protein 3 (IFITM3), an antiviral immune effector gene not previously studied in human platelets and MKs. IFITM3 was markedly upregulated in platelets isolated from patients during clinical influenza and dengue virus (DENV) infections. Lower IFITM3 expression in platelets correlated with increased illness severity and mortality in patients. Administering a live, attenuated DENV vaccine to healthy subjects significantly increased platelet IFITM3 expression. Infecting human MKs with DENV selectively increased type I interferons and IFITM3. Overexpression of IFITM3 in MKs was sufficient to prevent DENV infection. In naturally occurring, genetic loss-of-function studies, MKs from healthy subjects harboring a homozygous mutation in IFITM3 (rs12252-C, a common single-nucleotide polymorphism in areas of the world where DENV is endemic) were significantly more susceptible to DENV infection. DENV-induced MK secretion of interferons prevented infection of bystander MKs and hematopoietic stem cells. Thus, viral infections upregulate IFITM3 in human platelets and MKs, and IFITM3 expression is associated with adverse clinical outcomes. These observations establish, for the first time, that human MKs possess antiviral functions, preventing DENV infection of MKs and hematopoietic stem cells after local immune signaling.

Seroprevalence of Malaria and Hepatitis B Coinfection among Pregnant Women in Tamale Metropolis of Ghana: A Cross-Sectional Study

Background

Coinfections are becoming common risk factors that may contribute to the increased burden of morbidity in pregnancy. The aim of this study was to assess the seroprevalence of coinfections of malaria, hepatitis B (HBV), human immunodeficiency virus (HIV), and syphilis among pregnant women attending antenatal clinics (ANC) in the Tamale Metropolis.

Methods

By means of rapid diagnostic tests (RDTs), pregnant women attending the Tamale Teaching Hospital (TTH) were screened for malaria, HBV infection, HIV infection, and syphilis from March 2013 to February 2015. Haemoglobin (Hb) values, sickling, and glucose-6-phosphate dehydrogenase deficiency (G6PDd) statuses were also assessed using full blood count (FBC), sodium metabisulphite, and methaemoglobin reduction tests, respectively. Logistic regression analysis was performed to estimate the risks/odds ratios (ORs) for the coinfections and other variables (age, gravidity, and time of the first ANC visit) with 95% confidence intervals (CIs) and set p values for accepting any differences at <0.05.

Results

Within the two-year study period, data were collected from 3,127 pregnant women. The mean age (SD) of the pregnant women was 28.5 (±5.0) years. Of the total number, seroprevalence was high for malaria (11.6%) and HBV infection (4.2%) and low for HIV infection (1.0%) and syphilis (0.4%) monoinfections. Mal/HBV coinfection was higher (0.7%) when compared with Mal/HIV (0.1%), Mal/syphilis (0.0%), HBV/HIV (0.0%), HBV/syphilis (0.1%), and HIV/syphilis (0.0%) coinfections. The mean Hb (g/dl) for the women with the four monoinfections was significantly different from one another (p=0.009). Pregnant women with malaria infection were about 2 times more likely to be coinfected with HBV even after adjusting for potential confounders (adjusted odds ratio (AOR) = 1.66, 95% CI = 1.04-2.65, p=0.031). Those in their third trimester and visiting the ANC for the first time were significantly less likely to be infected with HBV (AOR = 0.45, 95% CI = 0.28-0.73, p=0.001), with malaria/HBV coinfection (AOR = 0.09, 95% CI = 0.01-0.68, p=0.020), and with any coinfection (AOR = 0.19, 95% CI = 0.06-0.63, p=0.007).

Conclusion

A comparatively high seroprevalence of malaria and its coinfection with HBV in pregnant women was observed in this study. Considering the effects that both malaria and HBV have on the liver, it would be expedient to conduct further studies to assess liver function among malaria/HBV-infected individuals, while interventions to prevent coinfections among pregnant women are intensified.

Development of a new knock-in mouse model and evaluation of pharmacological activities of lusutrombopag, a novel, nonpeptidyl small-molecule agonist of the human thrombopoietin receptor c-Mpl

Lusutrombopag (S-888711), an oral small-molecule thrombopoietin receptor (TPOR) agonist, has gained first approval as a drug to treat thrombocytopenia of chronic liver disease in patients undergoing elective invasive procedures in Japan. Preclinical studies were performed to evaluate its efficacy against megakaryopoiesis and thrombopoiesis. To investigate the proliferative activity and efficacy of megakaryocytic colony formation via human TPOR, lusutrombopag was applied to cultured human c-Mpl-expressing Ba/F3 (Ba/F3-hMpl) cells and human bone marrow-derived CD34-positive cells, respectively. Lusutrombopag caused a robust increase in Ba/F3-hMpl cells by activating pathways in a manner similar to that of thrombopoietin and induced colony-forming units-megakaryocyte and polyploid megakaryocytes in human CD34-positive cells. Because lusutrombopag has high species specificity for human TPOR, there was no suitable experimental animal model for drug evaluation, except for immunodeficient mouse-based xenograft models. Therefore, a novel genetically modified knock-in mouse, TPOR-Ki/Shi, was developed by replacing mouse Mpl with human-mouse chimera Mpl. In TPOR-Ki/Shi mice, lusutrombopag significantly increased circulating platelets in a dose-dependent manner during 21-day repeated oral administration. Histopathological study of the TPOR-Ki/Shi mice on day 22 also revealed a significant increase in megakaryocytes in the bone marrow. These results indicate that lusutrombopag acts on human TPOR to upregulate differentiation and proliferation of megakaryocytic cells, leading to platelet production.

The role of polymorphonuclear neutrophils during HIV-1 infection

It is well-recognized that human immunodeficiency virus type-1 (HIV-1) mainly targets CD4⁺ T cells and macrophages. Nonetheless, during the past three decades, a huge number of studies have reported that HIV-1 can directly or indirectly target other cellular components of the immune system including CD8⁺ T cells, B cells, dendritic cells, natural killer cells, and polymorphonuclear neutrophils (PMNs), among others. PMNs are the most abundant leukocytes in the human circulation, and are known to play principal roles in the elimination of invading pathogens, regulating different immune responses, healing of injured tissues, and maintaining mucosal homeostasis. Until recently, little was known about the impact of HIV-1 infection on PMNs as well as the impact of PMNs on HIV-1 disease progression. This is because early studies focused on neutropenia and recurrent microbial infections, particularly, during advanced disease. However, recent studies have extended the investigation area to cover new aspects of the interactions between HIV-1 and PMNs. This review aims to summarize these advances and address the impact of HIV-1 infection on PMNs as well as the impact of PMNs on HIV-1 disease progression to better understand the pathophysiology of HIV-1 infection.

The use of RetroNectin in studies requiring in vitro HIV-1 infection of human hematopoietic stem/progenitor cells

Human immunodeficiency virus (HIV) causes damage, directly or indirectly, to the whole hematopoietic system, including CD34⁺ hematopoietic stem/progenitor cells (HSPCs). CXCR4-tropic strains of HIV-1 may affect the function of CD34⁺CXCR4⁺ progenitor cells either by infecting the cells or modifying the dynamics of more differentiated hematopoietic cells. However, CD34⁺ cells are known for their resistance to HIV-1 infection in vitro, which restricts any detailed analysis of the impact of HIV on HSPCs. We report the use of RetroNectin, a recombinant fibronectin fragment used for gene transfer with lentiviral vectors, to overcome the limitation associated with CD34⁺ cell resistance to HIV-1 infection. RetroNectin coating of plates improved in vitro HIV-1 infectivity on human CD34⁺ cells by 10 fold. This resulted in stable HIV-1 infection for 5 weeks in an OP9-DL1 coculture. These results suggest that RetroNectin may be a useful tool for long-term monitoring of in vitro HIV-infected CD34⁺ cells.

Virus–Platelet Associations

Virus–platelet interplay is complex. Diverse virus types have been shown to associate with numerous distinct platelet receptors. This association can benefit the virus or the host, and thus the platelet is somewhat of a renegade. Evidence is accumulating to suggest that viruses are capable of entering platelets. For at least one type of RNA virus (dengue virus), the platelet has the necessary post-translational and packaging machinery required for production of replicative viral progeny. As a facilitator of immunity, the platelet also participates in eradicating the virus by direct and indirect mechanisms involving presentation of the pathogen to the innate and adaptive immune systems, thus enhancing inflammation by release of cytokines and other agonists. Virus-induced thrombocytopenia is caused by tangential imbalance of thrombopoeisis, autoimmunity, and loss of platelet function and integrity.

Thrombocytopenia and infections

INTRODUCTION

Acquired thrombocytopenia recognizes a myriad of causes. Among these, infectious diseases play a relevant role since a low platelet count is commonplace along with other abnormal laboratory data. Areas covered: This narrative review, after a brief presentation of the possible pathogenic mechanisms, is focused on the most prevalent infections associated with thrombocytopenia, namely those attributable to hepatitis C virus (HCV), human immunodeficiency virus (HIV) and Helicobacter pylori. Expert commentary: An underlying HCV or HIV infection should always be suspected in patients at risk who present with isolated thrombocytopenia. The eradication of Helicobacter pylori is advisable in infected patients with secondary immune thrombocytopenia, because this will increase the platelet count in a substantial number of cases, thus avoiding more aggressive and prolonged treatments.

Anemia in combined antiretroviral treatment-naive HIV-infected patients in China: A retrospective study of prevalence, risk factors, and mortality

Anemia is one of the most important complications of HIV infection. In China, the prevalence, risk factors, and association between anemia and prognosis in HIV-infected patients are poorly elucidated. We analyzed data from 3452 HIV-infected patients not yet on combined antiretroviral therapy (cART) attending Beijing Ditan Hospital from June, 2003 to December, 2015. The overall prevalence of anemia was 9.8% (7.6% mild, 1.9% moderate, and 0.2% severe anemia). Female sex (odds ratio [OR] = 3.71, 95% confidence interval [CI]: 1.46-6.51, p = 0.003), age 40-59 years (OR = 2.54, 95% CI: 1.59-4.05, p < 0.001), body mass index < 18.5 kg/m² (OR = 2.23, 95% CI: 1.31-3.79, p = 0.003), baseline HIV RNA CI: 1.32-5.99, p = 0.007) were risk factors for anemia. Age 40-59 years (adjusted hazard ratio [AHR] = 5.76, 95% CI: 1.62-20.55, p = 0.007), and anemia ‒ mild (AHR = 7.46, 95% CI: 1.48-37.50, p = 0.015), moderate (AHR = 9.89, CI: 1.35-72.38, p = 0.024), and severe (AHR = 28.29, 95% CI: 2.75-290.54, p = 0.005) anemia ‒ were associated with an increased hazard of death. In this cohort, mild anemia was most common. Anemia was associated with female sex, older age, lower body mass index, lower baseline CD4 count, and higher viral load. Moreover, anemia was associated with an increased risk of death. These findings should promote awareness among physicians to make a timely diagnosis of HIV and to help physicians prioritize prevention and intervention strategies for anemia in HIV-infected patients.

Factors associated with neurocognitive test performance at baseline: a substudy of the INSIGHT Strategic Timing of AntiRetroviral Treatment (START) trial

OBJECTIVES

We describe neuropsychological test performance (NP) in antiretroviral treatment (ART)-naïve HIV-positive individuals with CD4 cell counts above 500 cells/μL.

METHODS

In a neurology substudy of the International Network for Strategic Initiatives in Global HIV Trials (INSIGHT) Strategic Timing of AntiRetroviral Treatment (START) study, eight neurocognitive tests were administered. The primary measure of NP was the quantitative NP z-score (QNPZ-8), the average of the z-scores for the eight tests. Associations of baseline factors with QNPZ-8 scores were assessed by multiple regression. Mild neurocognitive impairment (NCI) was defined as z-scores < -1 in at least two of six cognitive domains.

RESULTS

A total of 608 participants had a median age of 34 years; 11% were women and 15% were black; the median time since HIV diagnosis was 0.9 years; the median CD4 cell count was 633 cells/μL; 19.9% had mild NCI. Better NP was independently associated with younger age, being white, higher body mass index (0.10 per 10 kg/m(2) higher), and higher haematocrit percentage (0.19 per 10% higher). Worse NP was associated with longer time since HIV diagnosis (-0.17 per 10 years), diabetes (-0.29) and higher Framingham risk score (-0.15 per 10 points higher). QNPZ-8 scores differed significantly between geographical locations, with the lowest scores in Brazil and Argentina/Chile.

CONCLUSIONS

This is the largest study of NP in ART-naïve HIV-positive adults with CD4 counts > 500 cells/μL. Demographic factors and diabetes were most strongly associated with NP. Unmeasured educational/sociocultural factors may explain geographical differences. Poorer NP was independently associated with longer time since HIV diagnosis, suggesting that untreated HIV infection might deleteriously affect NP, but the effect was small.

Relationship Between Blood Concentrations of Hepcidin and Anemia Severity, Mycobacterial Burden, and Mortality Among Patients With HIV-Associated Tuberculosis

Background

Anemia is very common in patients with human immunodeficiency virus (HIV)–associated tuberculosis, and hepcidin may be key in mediating this. We explored the relationship between blood hepcidin concentrations and anemia severity, mycobacterial burden and mortality in patients with HIV-associated tuberculosis.

Methods

Consecutive unselected HIV-infected adults in South Africa were systematically investigated for tuberculosis. Three groups were studied: 116 hospitalized inpatients with HIV infection and tuberculosis (hereafter, “hospitalized patients”), 58 ambulatory outpatients with HIV infection and newly diagnosed tuberculosis (hereafter, “ambulatory patients with tuberculosis”), and 58 ambulatory outpatients with HIV infection and without tuberculosis (hereafter, “ambulatory patients without tuberculosis”). Blood hepcidin concentrations were determined for all patients. Vital status at 3 months was determined, and independent predictors of mortality were identified.

Results

Median hepcidin concentrations were 38.8 ng/mL among hospitalized patients, 19.1 ng/mL among ambulatory patients with tuberculosis, and 5.9 ng/mL among ambulatory patients without tuberculosis (P < .001). In both groups with HIV-associated tuberculosis, hepcidin concentrations were strongly associated with greater anemia severity. Additionally, strong, graded associations were observed between hepcidin and composite indices of mycobacterial burden and dissemination. Patients dying within 3 months had significantly higher hepcidin concentrations, which independently predicted mortality.

Conclusions

High hepcidin concentrations were strongly associated with disseminated disease, anemia, and poor prognosis in patients with HIV-associated tuberculosis. Hepcidin may be a mechanistically important mediator underlying the high prevalence of severe anemia in these patients.

Nutritional status of HIV-infected patients during the first year HAART in two West African cohorts

OBJECTIVE

To examine the association between nutritional markers at initiation and during follow up in two different cohorts of HIV-infected adults initiating highly active antiretroviral therapy (HAART) in West Africa.

METHODS

The ATARAO study was a one year prospective study carried in Mali. It consisted of a sample of consecutive patients initiating HAART in one of four participating centers during that period. Data were collected at time of treatment initiation (baseline) and every 3 months thereafter. The ANRS 1290 study followed Senegalese patients recruited in similar conditions. Bivariate analyses were used to identify nutritional and immunological covariates of malnutrition at baseline. Longitudinal trajectories of body mass index, hemoglobin and albumin, and their associated factors, were evaluated using mixed linear models.

RESULTS

In ATARAO, 250 participants were retained for analyses; of which, 36% had a BMI < 18.5 kg/m(2), nearly 60% were anemic and 47.4% hypoalbuminemic at time of treatment initiation. At baseline, low hemoglobin, hypoalbuminemia and low CD4 levels were associated with a BMI < 18.5 kg/m(2). Similarly, low BMI, low albumin and low CD4 counts were linked to anemia; while, hypoalbuminemia was associated with low hemoglobin levels and CD4 counts. In ANRS, out of the 372 participants retained for analyses, 31% had a low BMI and almost 70% were anemic. At baseline, low BMI was associated with low hemoglobin levels and CD4 counts, while anemia was associated with low CD4 counts and female sex. While treatment contributed to early gains in BMI, hemoglobin and albumin in the first 6 months of treatment, initial improvements plateaued or subsided thereafter. Despite HAART, malnutrition persisted in both cohorts after one year, especially in those who were anemic, hypoalbuminemic or had a low BMI at baseline.

CONCLUSION

In ATARAO and ANRS, malnutrition was common across all indicators (BMI, hemoglobin, albumin) and persisted despite treatment. Low BMI, anemia and hypoalbuminemia were associated with attrition, and with a deficient nutritional and immunological status at baseline, as well as during treatment. In spite of therapy, malnutrition is associated with negative clinical and treatment outcomes which suggests that HAART may not be sufficient to address co-existing nutritional deficiencies.

Platelets Contribute to BBB Disruption Induced by HIV and Alcohol

The role of platelets in the neurological diseases that underlie cognitive impairment has attracted increasing attention in recent years. Multiple pathways in platelets contribute to host defenses, as well as to CNS function. In the current study, we hypothesize that the Blood Brain Barrier (BBB) is disrupted when exposed to platelets from patients with triple Co-morbidity (hazardous alcohol users+ HIV+ thrombocytopenia), compared to those with dual, single or no morbidity (HIV only, alcohol only or healthy controls).

Platelets and infection - an emerging role of platelets in viral infection

Platelets are anucleate blood cells that play a crucial role in the maintenance of hemostasis. While platelet activation and elevated platelet counts (thrombocytosis) are associated with increased risk of thrombotic complications, low platelet counts (thrombocytopenia) and several platelet function disorders increase the risk of bleeding. Over the last years, more and more evidence has emerged that platelets and their activation state can also modulate innate and adaptive immune responses and low platelet counts have been identified as a surrogate marker for poor prognosis in septic patients. Viral infections often coincide with platelet activation. Host inflammatory responses result in the release of platelet activating mediators and a pro-oxidative and pro-coagulant environment, which favors platelet activation. However, viruses can also directly interact with platelets and megakaryocytes and modulate their function. Furthermore, platelets can be activated by viral antigen-antibody complexes and in response to some viruses B-lymphocytes also generate anti-platelet antibodies. All these processes contributing to platelet activation result in increased platelet consumption and removal and often lead to thrombocytopenia, which is frequently observed during viral infection. However, virus-induced platelet activation does not only modulate platelet count but also shape immune responses. Platelets and their released products have been reported to directly and indirectly suppress infection and to support virus persistence in response to certain viruses, making platelets a double-edged sword during viral infections. This review aims to summarize the current knowledge on platelet interaction with different types of viruses, the viral impact on platelet activation, and platelet-mediated modulations of innate and adaptive immune responses.

Exacerbation of microcytic anemia associated with cessation of anti-retroviral therapy in an HIV-1-infected patient with beta thalassemia

We report a patient with Japanese minor β thalassemia and HIV-1 infection. The patient showed prolonged anemia, which was originally attributed to chronic parvovirus B19 infection. Twelve years later, the patient presented with exacerbation of microcytic anemia following cessation of anti-retroviral therapy; the exacerbation resolved when anti-retroviral therapy was resumed. Sequencing of the β globin gene revealed heterozygosity for a four-nucleotides deletion at codon 41/42 and minor β thalassemia was confirmed. Because HIV-1-infected patients frequently show anemia due to nutritional deficiencies, opportunistic infections, AIDS-related malignancies, drug treatment and a direct effect of HIV-1 on the bone marrow, it is likely to overlook other causes of anemia. Thalassemia should be considered in the differential diagnosis of anemia even in HIV-1 infected patients, when microcytic anemia without iron deficiency is observed. Our case suggested that active HIV infection may have worsened β thalassemia, and early introduction of anti-retroviral therapy is beneficial for the recovery of anemia.

Reprogramming the host: Modification of cell functions upon viral infection

Viruses and their hosts have co-evolved for million years. In order to successfully replicate their genome, viruses need to usurp the biosynthetic machinery of the host cell. Depending on the complexity and the nature of the genome, replication might involve or not a relatively large subset of viral products, in addition to a number of host cell factors, and take place in several subcellular compartments, including the nucleus, the cytoplasm, as well as virus-induced, rearranged membranes. Therefore viruses need to ensure the correct subcellular localization of their effectors and to be capable of disguising from the cellular defensive mechanisms. In addition, viruses are capable of exploiting host cell activities, by modulating their post-translational modification apparatus, resulting in profound modifications in the function of cellular and viral products. Not surprisingly infection of host cells by these parasites can lead to alterations of cellular differentiation and growing properties, with important pathogenic consequences. In the present hot topic highlight entitled “Reprogramming the host: modification of cell functions upon viral infection”, a number of leading virologists and cell biologist thoroughly describe recent advances in our understanding of how viruses modulate cellular functions to achieve successful replication and propagation at the expenses of human cells.