Prevalence and predictors of kaposi sarcoma herpes virus seropositivity: a cross-sectional analysis of HIV-infected adults initiating ART in Johannesburg, South Africa

Prevalence and trends of advanced HIV disease among antiretroviral therapy-naïve and antiretroviral therapy-experienced patients in South Africa between 2010-2021: a systematic review and meta-analysis

BACKGROUND

Despite the significant progress made in South Africa in getting millions of individuals living with HIV into care, many patients still present or re-enter care with Advanced HIV Disease (AHD). We aimed to estimate the prevalence of AHD among ART-naive and ART-experienced patients in South Africa using studies published between January 2010 and May 2022.

METHODS

We searched for relevant data on PubMed, CINAHL, Scopus and other sources, with a geographical filters limited to South Africa, up to May 31, 2022. Two reviewers conducted all screening, eligibility assessment, data extraction, and critical appraisal. We synthesized the data using the inverse-variance heterogeneity model and Freeman-Tukey transformation. We assessed heterogeneity using the I2 statistic and publication bias using the Egger and Begg's test.

RESULTS

We identified 2,496 records, of which 53 met the eligibility criteria, involving 11,545,460 individuals. The pooled prevalence of AHD among ART-naive and ART-experienced patients was 43.45% (95% CI 40.1-46.8%, n = 53 studies) and 58.6% (95% CI 55.7 to 61.5%, n = 2) respectively. The time trend analysis showed a decline of 2% in the prevalence of AHD among ART-naive patients per year. However, given the high heterogeneity between studies, the pooled prevalence should be interpreted with caution.

CONCLUSION

Despite HIV's evolution to a chronic disease, our findings show that the burden of AHD remains high among both ART-naive and ART-experienced patients in South Africa. This emphasizes the importance of regular measurement of CD4 cell count as an essential component of HIV care. In addition, providing innovative adherence support and interventions to retain ART patients in effective care is a crucial priority for those on ART.

Seroprevalence and molecular diversity of Human Herpesvirus 8 among people living with HIV in Brazzaville, Congo

Human herpesvirus 8 (HHV8) is endemic in Africa, although studies of this infection are rare in Congo. We evaluated seroprevalence and HHV-8 diversity among people living with HIV. We included 353 patients receiving highly active antiretroviral therapy. Antibodies against HHV-8 latency-associated nuclear antigen were detected by indirect immunofluorescence. In HHV-8 positive patients, we performed HHV-8 quantification in blood and saliva by real-time PCR and typing by Sanger sequencing of K1 open reading frame. HHV-8 seroprevalence was 19%, being male (odd ratio [OR] = 1.741, [95% Confidence interval {CI}, 0.97-3.07]; p = 0.0581) and having multiple sex partners before HIV diagnosis (OR = 1.682, [CI 95%, 0.97-2.92]; p = 0.0629) tended to be associated with HHV-8 seropositivity. Of the 64 HHV-8 seropositive patients, HHV-8 DNA was detected in 10 (16%) in saliva, 6 (9%) in whole-blood and in 2 (3%) in both whole-blood and saliva. Three out of 6 HHV-8 strains were subtypes A5, 2 subtype B1 and 1 subtype C. HHV-8 seroprevalence was relatively low with more frequent carriage in men, associated with asymptomatic oral excretion and a predominance of subtype A5. These data tend to support the hypothesis of horizontal transmission in people living with HIV in Brazzaville.

The Contribution of Kaposi's Sarcoma-Associated Herpesvirus to Mortality in Hospitalized Human Immunodeficiency Virus-Infected Patients Being Investigated for Tuberculosis in South Africa

BACKGROUND

Despite increasing numbers of human immunodeficiency virus (HIV)-infected South Africans receiving antiretroviral therapy (ART), tuberculosis (TB) remains the leading cause of mortality. Approximately 25% of patients treated for TB have microbiologically unconfirmed diagnoses. We assessed whether elevated Kaposi's sarcoma-associated herpesvirus (KSHV) viral load (VL) contributes to mortality in hospitalized HIV-infected patients investigated for TB.

METHODS

Six hundred eighty-two HIV-infected patients admitted to Khayelitsha Hospital, South Africa, were recruited, investigated for TB, and followed for 12 weeks. KSHV serostatus, peripheral blood KSHV-VL, and KSHV-associated clinical correlates were evaluated.

RESULTS

Median CD4 count was 62 (range, 0-526) cells/μL; KSHV seropositivity was 30.7% (95% confidence interval [CI], 27%-34%); 5.8% had detectable KSHV-VL (median, 199.1 [range, 13.4-2.2 × 106] copies/106 cells); 22% died. Elevated KSHV-VL was associated with mortality (adjusted odds ratio, 6.5 [95% CI, 1.3-32.4]) in patients without TB or other microbiologically confirmed coinfections (n = 159). Six patients had "possible KSHV-inflammatory cytokine syndrome" (KICS): 5 died, representing significantly worse survival (P < .0001), and 1 patient was diagnosed with KSHV-associated multicentric Castleman disease at autopsy.

CONCLUSIONS

Given the association of mortality with elevated KSHV-VL in critically ill HIV-infected patients with suspected but not microbiologically confirmed TB, KSHV-VL and KICS criteria may guide diagnostic and therapeutic evaluation.

HHV-8 Seroprevalence and Genotype Distribution in Africa, 1998⁻2017: A Systematic Review

Human herpes virus type 8 (HHV-8) is the causative agent of Kaposi's sarcoma (KS). We systematically reviewed literature published between 1998 and 2017, according to the PRISMA guidelines, to understand the distribution of HHV-8 infection in Africa. More than two-thirds (64%) of studies reported on seroprevalence and 29.3% on genotypes; 9.5% were on both seroprevalence and genotypes. About 45% of African countries had data on HHV-8 seroprevalence exclusively, and more than half (53%) had data on either seroprevalence or genotypes. Almost half (47%) of the countries had no data on HHV-8 infection. There was high heterogeneity in the types of tests and interpretation algorithms used in determining HHV-8 seropositivity across the different studies. Generally, seroprevalence ranged from 2.0% in a group of young children in Eritrea to 100% in a small group of individuals with KS in Central African Republic, and in a larger group of individuals with KS in Morocco. Approximately 16% of studies reported on children. Difference in seroprevalence across the African regions was not significant (95% CI, χ² = 0.86; p = 0.35), although specifically a relatively significant level of infection was observed in HIV-infected children. About 38% of the countries had data on K1 genotypes. K1 genotypes A, A5, B, C, F and Z occurred at frequencies of 5.3%, 26.3%, 42.1%, 18.4%, 5.3% and 2.6%, respectively. Twenty-three percent of the countries had data for K15 genotypes, and genotypes P, M and N occurred at frequencies of 52.2%, 39.1%, and 8.7%, respectively. Data on HHV-8 inter-genotype recombinants in Africa are scanty. HHV-8 may be endemic in the entire Africa continent but there is need for a harmonized testing protocol for a better understanding of HHV-8 seropositivity. K1 genotypes A5 and B, and K15 genotypes P and M, from Africa, should be considered in vaccine design efforts.

Treatment of Kaposi Sarcoma Herpesvirus-Associated Multicentric Castleman Disease

Kaposi sarcoma herpesvirus (KSHV)-associated multicentric Castleman disease (MCD) is a rare, polyclonal lymphoproliferative disorder characterized by flares of inflammatory symptoms, edema, cytopenias, lymphadenopathy, and splenomegaly. Diagnosis requires a lymph node biopsy. Pathogenesis is related to dysregulated inflammatory cytokines, including human and viral interleukin-6. Rituximab alone or in combination with chemotherapy, such as liposomal doxorubicin, has led to an overall survival of over 90% at 5 years. Experimental approaches to treatment include virus activated cytotoxic therapy with high-dose zidovudine and valganciclovir and targeting human interleukin-6 activity. Despite successful treatment of KSHV-MCD, patients remain at high risk for developing non-Hodgkin lymphomas.

HIV-associated Kaposi sarcoma and related diseases

: The search for the etiologic agent for Kaposi sarcoma led to the discovery of Kaposi sarcoma-associated herpesvirus (KSHV) in 1994. KSHV, also called human herpesvirus-8, has since been shown to be the etiologic agent for several other tumors and diseases, including primary effusion lymphoma (PEL), an extracavitary variant of PEL, KSHV-associated diffuse large B-cell lymphoma, a form of multicentric Castleman disease, and KSHV inflammatory cytokine syndrome. KSHV encodes several genes that interfere with innate and specific immunity, thwart apoptosis, enhance cell proliferation and cytokine production, and promote angiogenesis, and these play important roles in disease pathogenesis. HIV is an important cofactor in Kaposi sarcoma pathogenesis, and widespread use of antiretroviral therapy has reduced Kaposi sarcoma incidence. However, Kaposi sarcoma remains the second most frequent tumor arising in HIV-infected patients in the United States and is particularly common in sub-Saharan Africa. KSHV prevalence varies substantially in different populations. KSHV is secreted in saliva, and public health measures to reduce its spread may help reduce the incidence of KSHV-associated diseases. Although there have been advances in the treatment of Kaposi sarcoma, KSHV-multicentric Castleman disease, and PEL, improved therapies are needed, especially those that are appropriate for Kaposi sarcoma in resource-poor regions.

Seroprevalence of human herpesvirus 8 and its impact on the hemoglobin level in patients of end stage of renal diseases

The incidence of Kaposi's sarcoma (KS) is increasing among renal transplant recipients. Patients with end-stage renal disease (ESRD) are immunocompromised and are candidates for renal transplantation, but HHV8 seroprevalence in ESRD patients has not been well documented. A cross-sectional study of 286 ESRD patients and 281 matched subjects without kidney disease was conducted at the First People's Hospital of Huzhou, Zhejiang province to explore the epidemiologic features of HHV8 among ESRD patients in China. Blood samples were collected and HHV8 antibodies and serologic indices were measured. The seroprevalence of HHV8 was 15.3% for ESRD patients and 8.9% for the comparison group. A significant difference in the geometric mean titer (GMT) of the HHV8 antibodies was detected between ESRD patients and the comparison group (617.1 vs 291.7; P = 0.042). The average level of hemoglobin was 11.56 ± 1.78 g/dL for the ESRD group and 13.73 ± 1.42 g/dL for the comparison group, (P > 0.05). Multiple linear regression revealed a negative association between HHV8 infection and plasma hemoglobin concentration (β = -0.682, P = 0.036). We found a higher HHV8 prevalence and a higher level of HHV8 antibody GMT in ESRD patients than the comparison group, which indicate a high risk of posttransplantation KS.

Cohort profile: the Right to Care Clinical HIV Cohort, South Africa

PURPOSE

The research objectives of the Right to Care Clinical HIV Cohort analyses are to: (1) monitor treatment outcomes (including death, loss to follow-up, viral suppression and CD4 count gain among others) for patients on antiretroviral therapy (ART); (2) evaluate the impact of changes in the national treatment guidelines around when to initiate ART on HIV treatment outcomes; (3) evaluate the impact of changes in the national treatment guidelines around what ART regimens to initiate on drug switches; (4) evaluate the cost and cost-effectiveness of HIV treatment delivery models; (5) evaluate the need for and outcomes on second-line and third-line ART; (6) evaluate the impact of comorbidity with non-communicable diseases on HIV treatment outcomes and (7) evaluate the impact of the switch to initiating all patients onto ART regardless of CD4 count.

PARTICIPANTS

The Right to Care Clinical HIV Cohort is an open cohort of data from 10 clinics in two provinces within South Africa. All clinics include data from 2004 onwards. The cohort currently has data on over 115 000 patients initiated on HIV treatment and patients are followed up every 3-6 months for clinical and laboratory monitoring.

FINDINGS TO DATE

Cohort data includes information on demographics, clinical visit, laboratory data, medication history and clinical diagnoses. The data have been used to identify rates and predictors of first-line failure, to identify predictors of mortality for patients on second-line (eg, low CD4 counts) and to show that adolescents and young adults are at increased risk of unsuppressed viral loads compared with adults.

FUTURE PLANS

Future analyses will inform national models of HIV care and treatment to improve HIV care policy in South Africa.

Rapid Multiplexed Immunoassay for Detection of Antibodies to Kaposi's Sarcoma-Associated Herpesvirus

Diagnosis of KSHV-infected individuals remains a challenge. KSHV prevalence is high in several populations with high prevalence of HIV, leading to increased risk of development of Kaposi’s sarcoma (KS). While current assays are reliable for detecting antibodies to KSHV, none are routinely utilized to identify individuals with KSHV infection and thus at increased risk for KS due to assay complexity, lack of access to testing, and cost, particularly in resource-limited settings. Here we describe the addition of KSHV proteins LANA and K8.1 to a previously evaluated HIV/co-infection multiplexed fluorescence immunoassay system. This study demonstrates assay performance by measuring antibody reactivity for KSHV and HIV-1 in a collection of clinical specimens from patients with biopsy-proven KS and sourced negative controls. The KSHV assay correctly identified 155 of 164 plasma samples from patients with biopsy-proven KS and 85 of 93 KSHV antibody (Ab)-negative samples for a sensitivity of 95.1% and specificity of 91.4%. Assay performance for HIV-1 detection was also assessed with 100% agreement with independently verified HIV-1 Ab-positive and Ab-negative samples. These results demonstrate good sensitivity and specificity for detection of antibody to KSHV antigens, and demonstrate the potential for multiplexed co-infection testing in resource-limited settings to identify those at increased risk for HIV-1-related complications.

Excellent clinical outcomes and retention in care for adults with HIV-associated Kaposi sarcoma treated with systemic chemotherapy and integrated antiretroviral therapy in rural Malawi

INTRODUCTION

HIV-associated Kaposi sarcoma (HIV-KS) is the most common cancer in Malawi. In 2008, the non-governmental organization, Partners In Health, and the Ministry of Health established the Neno Kaposi Sarcoma Clinic (NKSC) to treat HIV-KS in rural Neno district. We aimed to evaluate 12-month clinical outcomes and retention in care for HIV-KS patients in the NKSC, and to describe our implementation model, which featured protocol-guided chemotherapy, integrated antiretroviral therapy (ART) and psychosocial support delivered by community health workers.

METHODS

We conducted a retrospective cohort study using routine clinical data from 114 adult HIV-KS patients who received ART and ≥1 chemotherapy cycle in the NKSC between March 2008 and February 2012.

RESULTS

At enrolment 97% of patients (n/N=103/106) had advanced HIV-KS (stage T1). Most patients were male (n/N=85/114, 75%) with median age 36 years (interquartile range, IQR: 29-42). Patients started ART a median of 77 days prior to chemotherapy (IQR: 36-252), with 97% (n/N=105/108) receiving nevirapine/lamivudine/stavudine. Following standardized protocols, we treated 20 patients (18%) with first-line paclitaxel and 94 patients (82%) with bleomycin plus vincristine (BV). Of the 94 BV patients, 24 (26%) failed to respond to BV requiring change to second-line paclitaxel. A Division of AIDS grade 3/4 adverse event occurred in 29% of patients (n/N=30/102). Neutropenia was the most common grade 3/4 event (n/N=17/102, 17%). Twelve months after chemotherapy initiation, 83% of patients (95% CI: 74-89%) were alive, including 88 (77%) retained in care. Overall survival (OS) at 12 months did not differ by initial chemotherapy regimen (p=0.6). Among patients with T1 disease, low body mass index (BMI) (adjusted hazard ratio, aHR=4.10, 95% CI: 1.06-15.89) and 1 g/dL decrease in baseline haemoglobin (aHR=1.52, 95% CI: 1.03-2.25) were associated with increased death or loss to follow-up at 12 months.

CONCLUSIONS

The NKSC model resulted in infrequent adverse events, low loss to follow-up and excellent OS. Our results suggest it is safe, effective and feasible to provide standard-of-care chemotherapy regimens from the developed world, integrated with ART, to treat HIV-KS in rural Malawi. Baseline BMI and haemoglobin may represent important patient characteristics associated with HIV-KS survival in rural sub-Saharan Africa.

Incidence rate of Kaposi sarcoma in HIV-infected patients on antiretroviral therapy in Southern Africa: a prospective multicohort study

BACKGROUND

The risk of Kaposi sarcoma (KS) among HIV-infected persons on antiretroviral therapy (ART) is not well defined in resource-limited settings. We studied KS incidence rates and associated risk factors in children and adults on ART in Southern Africa.

METHODS

We included patient data of 6 ART programs in Botswana, South Africa, Zambia, and Zimbabwe. We estimated KS incidence rates in patients on ART measuring time from 30 days after ART initiation to KS diagnosis, last follow-up visit, or death. We assessed risk factors (age, sex, calendar year, WHO stage, tuberculosis, and CD4 counts) using Cox models.

FINDINGS

We analyzed data from 173,245 patients (61% female, 8% children aged <16 years) who started ART between 2004 and 2010. Five hundred and sixty-four incident cases were diagnosed during 343,927 person-years (pys). The overall KS incidence rate was 164/100,000 pys [95% confidence interval (CI): 151 to 178]. The incidence rate was highest 30-90 days after ART initiation (413/100,000 pys; 95% CI: 342 to 497) and declined thereafter [86/100,000 pys (95% CI: 71 to 105), >2 years after ART initiation]. Male sex [adjusted hazard ratio (HR): 1.34; 95% CI: 1.12 to 1.61], low current CD4 counts (≥500 versus <50 cells/μL, adjusted HR: 0.36; 95% CI: 0.23 to 0.55), and age (5-9 years versus 30-39 years, adjusted HR: 0.20; 95% CI: 0.05 to 0.79) were relevant risk factors for developing KS.

INTERPRETATION

Despite ART, KS risk in HIV-infected persons in Southern Africa remains high. Early HIV testing and maintaining high CD4 counts is needed to further reduce KS-related morbidity and mortality.

Kaposi's Sarcoma in HIV-infected patients in South Africa: Multicohort study in the antiretroviral therapy era

The incidence of Kaposi's Sarcoma (KS) is high in South Africa but the impact of antiretroviral therapy (ART) is not well defined. We examined incidence and survival of KS in HIV-infected patients enrolled in South African ART programs. We analyzed data of three ART programs: Khayelitsha township and Tygerberg Hospital programs in Cape Town and Themba Lethu program in Johannesburg. We included patients aged >16 years. ART was defined as a regimen of at least three drugs. We estimated incidence rates of KS for patients on ART and not on ART. We calculated Cox models adjusted for age, sex and time-updated CD4 cell counts and HIV-1 RNA. A total of 18,254 patients (median age 34.5 years, 64% female, median CD4 cell count at enrolment 105 cells/μL) were included. During 37,488 person-years follow-up 162 patients developed KS. The incidence was 1,682/100,000 person-years (95% confidence interval [CI] 1,406-2,011) among patients not receiving ART and 138/100,000 person-years (95% CI 102-187) among patients on ART. The adjusted hazard ratio comparing time on ART with time not on ART was 0.19 (95% CI 0.13-0.28). Low CD4 cell counts (time-updated) and male sex were also associated with KS. Estimated survival of KS patients at one year was 72.2% (95% CI 64.9-80.2) and higher in men than in women. The incidence of KS is substantially lower on ART than not on ART. Timely initiation of ART is essential to prevent KS and KS-associated morbidity and mortality in South Africa and other regions in Africa with a high burden of HIV.

Kaposi sarcoma-associated herpes virus and response to antiretroviral therapy: a prospective study of HIV-infected adults

BACKGROUND

The possible impact of coinfection with the Kaposi sarcoma-associated herpes virus (KSHV) on the response to antiretroviral therapy (ART) is unknown. Prospective studies are rare, particularly in Africa.

METHODS

We enrolled a prospective cohort of HIV-infected adults initiating ART in Johannesburg, South Africa. The subjects were defined as seropositive to KSHV if they were reactive to either KSHV lytic K8.1 or latent Orf73 antigen or to both. The subjects were followed from ART initiation until 18 months of treatment. HIV viral load and CD4 counts were tested 6 monthly. Linear generalized estimating and log-binomial regression models were used to estimate the effect of KSHV infection on immunologic recovery and response and HIV viral load suppression within 18 months after ART initiation.

RESULTS

Three hundred eighty-five subjects initiating ART from November 2008 to March 2009 were considered to be eligible including 184 (48%) KSHV+. The KSHV+ group was similar to the KSHV- in terms of age, gender, initiating CD4 count, body mass index, tuberculosis, and hemoglobin levels. The KSHV+ group gained a similar number of cells at 6 [difference of 10 cells per cubic millimeter, 95% confidence interval (CI): -11 to 31], 12 (3 cells per cubic millimeter, 95% CI: -19 to 25), and 18 months (24 cells per cubic millimeter, 95% CI: -13 to 61) compared with that gained by the KSHV- group. Adjusted relative risk of failure to suppress viral load to <400 copies per milliliter (1.03; 95% CI: 0.90 to 1.17) were similar for KSHV+ and KSHV- by 6 months on treatment.

CONCLUSIONS

In a population with a high KSHV prevalence, HIV-positive adults coinfected with KSHV achieved similar immunologic and virologic responses to ART early after treatment initiation compared with those with KSHV-.

Recent advances in Kaposi sarcoma herpesvirus-associated multicentric Castleman disease

PURPOSE OF REVIEW

The discovery of Kaposi sarcoma herpesvirus (KSHV) led to recognition of KSHV-associated multicentric Castleman disease (MCD) as a distinct lymphoproliferative disorder. The pathogenesis of KSHV-MCD is attributed to proliferation of KSHV-infected B cells, production of KSHV-encoded viral interleukin 6 by these cells, and dysregulation of human interleukin 6 and interleukin 10. This article reviews advances in the field of disease pathogenesis and targeted therapies.

RECENT FINDINGS

Our understanding of the pathogenesis of KSHV-MCD has increased in recent years and improved therapies have been developed. Recent studies demonstrate that the anti-CD20 monoclonal antibody, rituximab, as well as virus-activated cytotoxic therapy using high-dose zidovudine and valganciclovir, can control symptoms and decrease adenopathy. With treatment, 1-year survival now exceeds 85%. Interestingly, even in the absence of pathologic findings of MCD, KSHV-infected patients may have inflammatory symptoms, excess cytokine production, and elevated KSHV viral load similar to KSHV-associated MCD. The term KSHV-associated inflammatory cytokine syndrome has been proposed to describe such patients.

SUMMARY

Recent advances in targeted therapy have improved outcomes in KSHV-MCD, and decreased need for cytotoxic chemotherapy. Improved understanding of the pathogenesis of KSHV-MCD and KSHV-associated inflammatory cytokine syndrome is needed, and will likely lead to additional advances in therapy for these disorders.

Cohort profile: the Themba Lethu Clinical Cohort, Johannesburg, South Africa

The Themba Lethu Clinical Cohort was established in 2004 to allow large patient-level analyses from a single HIV treatment site to evaluate National Treatment Guidelines, answer questions of national and international policy relevance and to combine an economic and epidemiologic focus on HIV research. The current objectives of the Themba Lethu Clinical Cohort analyses are to: (i) provide cohort-level information on the outcomes of HIV treatment; (ii) evaluate aspects of HIV care and treatment that have policy relevance; (iii) evaluate the cost and cost-effectiveness of different approaches to HIV care and treatment; and (iv) provide a platform for studies on improving HIV care and treatment. Since 2004, Themba Lethu Clinic has enrolled approximately 30,000 HIV-positive patients into its HIV care and treatment programme, over 21,000 of whom have received anti-retroviral therapy since being enrolled. Patients on treatment are typically seen at least every 3 months with laboratory monitoring every 6 months to 1 year. The data collected include demographics, clinical visit data, laboratory data, medication history and clinical diagnoses. Requests for collaborations on analyses can be submitted to our data centre.