Limited HIV-associated neuropathologies and lack of immune activation in sub-saharan African individuals with late-stage subtype C HIV-1 infection.

Although previous studies have suggested that subtype B HIV-1 proviruses in the brain are associated with physiological changes and immune activation accompanied with microgliosis and astrogliosis, and indicated that both HIV-1 subtype variation and geographical location might influence the neuropathogenicity of HIV-1 in the brain. The natural course of neuropathogenesis of the most widespread subtype C HIV-1 has not been adequately investigated, especially for people living with HIV (PLWH) in sub-Saharan Africa. To characterize the natural neuropathology of subtype C HIV-1, postmortem frontal lobe and basal ganglia tissues were collected from nine ART-naïve individuals who died of late-stage AIDS with subtype C HIV-1 infection, and eight uninfected deceased individuals as controls. Histological staining was performed on all brain tissues to assess brain pathologies. Immunohistochemistry (IHC) against CD4, p24, Iba-1, GFAP, and CD8 in all brain tissues was conducted to evaluate potential viral production and immune activation. Histological results showed mild perivascular cuffs of lymphocytes only in a minority of the infected individuals. Viral capsid p24 protein was only detected in circulating immune cells of one infected individual, suggesting a lack of productive HIV-1 infection of the brain even at the late-stage of AIDS. Notably, similar levels of Iba-1 or GFAP between HIV + and HIV- brain tissues indicated a lack of microgliosis and astrogliosis, respectively. Similar levels of CD8 + cytotoxic T lymphocyte (CTL) infiltration between HIV + and HIV- brain tissues indicated CTL were not likely to be involved within subtype C HIV-1 infected participants of this cohort. Results from this subtype C HIV-1 study suggest that there is a lack of productive infection and limited neuropathogenesis by subtype C HIV-1 even at late-stage disease, which is in contrast to what was reported for subtype B HIV-1 by other investigators.

Cannabis Use Associates With Reduced Proviral Burden and Inflammatory Cytokine in Tissues From Men With Clade C HIV-1 on Suppressive Antiretroviral Therapy.

BACKGROUND: Human immunodeficiency virus 1 (HIV-1) tissue reservoirs remain the main obstacle against an HIV cure. Limited information exists regarding cannabis's effects on HIV-1 infections in vivo, and the impact of cannabis use on HIV-1 parenchymal tissue reservoirs is unexplored. METHODS: To investigate whether cannabis use alters HIV-1 tissue reservoirs, we systematically collected 21 postmortem brain and peripheral tissues from 20 men with subtype C HIV-1 and with suppressed viral load enrolled in Zambia, 10 of whom tested positive for cannabis use. The tissue distribution and copies of subtype C HIV-1 LTR, gag, env DNA and RNA, and the relative mRNA levels of cytokines IL-1ß, IL-6, IL-10, and TGF-ß1 were quantified using PCR-based approaches. Utilizing generalized linear mixed models we compared persons with HIV-1 and suppressed viral load, with and without cannabis use. RESULTS: The odds of tissues harboring HIV-1 DNA and the viral DNA copies in those tissues were significantly lower in persons using cannabis. Moreover, the transcription levels of proinflammatory cytokines IL-1ß and IL-6 in lymphoid tissues of persons using cannabis were also significantly lower. CONCLUSIONS: Our findings suggested that cannabis use is associated with reduced sizes and inflammatory cytokine expression of subtype C HIV-1 reservoirs in men with suppressed viral load.

Co-infection and co-localization of Kaposi sarcoma-associated herpesvirus and Epstein-Barr virus in HIV-associated Kaposi sarcoma: a case report.

Kaposi sarcoma (KS), a multifocal vascular neoplasm frequently observed in HIV-positive individuals, primarily affects the skin, mucous membranes, visceral organs, and lymph nodes. KS is associated primarily with Kaposi sarcoma-associated herpesvirus (KSHV) infection. In this case report, we present a rare occurrence of co-infection and co-localization of KSHV and Epstein-Barr virus (EBV) in KS arising from the conjunctiva, which, to our knowledge, has not been reported previously. Immunohistochemistry (IHC), DNA polymerase chain reaction (PCR), and EBV-encoded RNA in situ hybridization (EBER-ISH) were utilized to demonstrate the presence of KSHV and EBV infection in the ocular KS lesion. Nearly all KSHV-positive cells displayed co-infection with EBV. In addition, the KS lesion revealed co-localization of KSHV Latency-Associated Nuclear Antigen (LANA) and EBV Epstein Barr virus Nuclear Antigen-1 (EBNA1) by multi-colored immunofluorescence staining with different anti-EBNA1 antibodies, indicating the possibility of interactions between these two gamma herpesviruses within the same lesion. Additional study is needed to determine whether EBV co-infection in KS is a common or an opportunistic event that might contribute to KS development and progression.

Yes-associated protein-1 overexpression in ocular surface squamous neoplasia; a potential diagnostic marker and therapeutic target.

Yes-associated protein-1 (YAP-1) is a Hippo system transcription factor, which serves as an oncogene in squamous cell carcinoma, and several solid tumors when the Hippo pathway is dysregulated. Yet, the activity of YAP-1 in ocular surface squamous neoplasia (OSSN) has not been determined. Here, we investigate the relationship between YAP-1 overexpression and OSSN. Using a cross-sectional study design, we recruited 227 OSSN patients from the University Teaching Hospitals in Lusaka, Zambia. Immunohistochemistry was used to assess YAP-1 protein overexpression in tumor tissue relative to surrounding benign squamous epithelium. OSSN patient samples (preinvasive, n = 62, 27% and invasive, n = 165, 73%) were studied. One hundred forty-nine invasive tumors contained adjacent preinvasive tissue, bringing the total number of preinvasive lesions examined to 211 (62 + 149). There was adjacent benign squamous epithelium in 50.2% (114/227) of OSSN samples. Nuclear YAP- 1 was significantly overexpressed in preinvasive (Fisher's (F): p <.0001, Monte Carlo (MC): p <.0001) and invasive (F: p <.0001, MC: p <.0001) OSSN in comparison to adjacent benign squamous epithelium when analyzed for basal keratinocyte positive count, staining intensity, expression pattern, and Immunostaining intensity-distribution index. YAP-1 expression did not differ between preinvasive and invasive OSSN (p >.05), keratinizing and non- keratinizing cancer (p >.05), or between T1/T2 and T3/T4 stages in invasive tumors (p >.05). However, grade 2 and 3 tumors had significantly stronger nucleus YAP-1 overexpression intensity than grade 1 tumors (F: p = .0078, MC: p = .0489). By immunohistochemistry, we identified significant overexpression (upregulation of YAP-1 protein expression) in preinvasive and invasive OSSN lesions compared to neighboring benign squamous epithelium. YAP-1 expression was significantly higher in poorly and moderately differentiated invasive squamous cancer than in well-differentiated carcinomas. Overexpression of YAP-1 within the margin of preinvasive and invasive OSSN, but not in the neighboring normal epithelium, indicates that it plays a role in the development and progression of OSSN.

Systematic post-mortem analysis of brain tissue from an HIV-1 subtype C viremic decedent revealed a paucity of infection and pathology.

Whether the human brain is a robust reservoir for HIV-1 subtype C has yet to be established. We aimed to determine whether HIV-1 subtype C infection can be detected in the brain tissue of a viremic individual at post-mortem and whether the viral burden was differential between different brain regions. This study reports a 38-year-old Zambian female decedent with severe wasting who was on Atripla for antiretroviral therapy. The cause of death was determined to be HIV/AIDS end-stage disease. The QuantStudio 3 Real-Time PCR System analyzed formalin-fixed paraffin-embedded tissue DNA from a systematic sampling of the entire left-brain hemisphere. Plasma and cerebral spinal fluid HIV-1 RNA loads were 576,123 and 14,962 copies/mL, respectively. The lymph node DNA viral load was 2316 copies per 106 cells. Two hundred and six (96.3%) tissue blocks had amplifiable DNA. HIV-1 viral DNA was detected in 35.9% of the blocks, the highest in the basal ganglia (66.7%) and the frontal lobe (46%). Overall, HIV detection was random, with low viral copies detected by quantitative polymerase chain reaction (qPCR); the lowest was observed in the occipital (median, IQR, range) 0.0 [0.0-0.0], 0.0-31.3, and the highest in the basal ganglia (mean ± SD, range, 125.1149.5, 0.0-350.0). Significant differences in HIV-1 DNA distribution were observed between the occipital versus parietal (p = 0.049), occipital versus frontal (p = 0.019), occipital versus basal ganglia (p = 0.005), cerebellum versus frontal (p = 0.021), cerebellum versus basal ganglia (p = 0.007), and temporal versus frontal (p = 0.034).

Subtype C HIV-1 reservoirs throughout the body in ART-suppressed individuals.

Subtype B HIV-1 reservoirs have been intensively investigated, but reservoirs in other subtypes and how they respond to antiretroviral therapy (ART) is substantially less established. To characterize subtype C HIV-1 reservoirs, we implemented postmortem frozen, as well as formalin fixed paraffin embedded (FFPE) tissue sampling of central nervous system (CNS) and peripheral tissues. HIV-1 LTR, gag, envelope (env) DNA and RNA was quantified using genomic DNA and RNA extracted from frozen tissues. RNAscope was used to localize subtype C HIV-1 DNA and RNA in FFPE tissue. Despite uniform viral load suppression in our cohort, PCR results showed that subtype C HIV-1 proviral copies vary both in magnitude and tissue distribution, with detection primarily in secondary lymphoid tissues. Interestingly, the appendix harbored proviruses in all subjects. Unlike subtype B, subtype C provirus was rarely detectable in the CNS, and there was no detectable HIV-1 RNA. HIV-1 RNA was detected in peripheral lymphoid tissues of 6 out of 8 ART-suppressed cases. In addition to active HIV-1 expression in lymphoid tissues, RNAscope revealed HIV RNA detection in CD4-expressing cells in the appendix, suggesting that this tissue was a previously unreported potential treatment-resistant reservoir for subtype C HIV-1.

High-risk human papillomavirus-associated vulvar neoplasia among women living with human immunodeficiency virus in Zambia.

Background: Globally, women living with HIV have a higher risk of vulvar neoplasia than HIV-negative women. Vulvar neoplasia among women living with HIV has not previously been characterised in Zambia. Objective: This study determined the clinical and pathologic features of vulvar neoplasia among women living with HIV at the University Teaching Hospital, Lusaka, Zambia. Methods: We conducted a cross-sectional study of vulvar lesions among 53 women living with HIV who presented with vulvar lesions between July 2017 and February 2018. The study assessed clinical and histological characteristics and prevalence of high-risk human papillomavirus (HRHPV). Results: Twenty-one patients were diagnosed with vulvar squamous cell carcinoma (VSCC), 20 with usual vulvar intraepithelial neoplasm (uVIN), and the rest with either benign lesions or non-neoplastic lesions (NNL). Participants' mean age was 40 years. Patients with VSCC were significantly older than those with NNL (mean (s.d.): 43 (21) vs 33 (10), p = 0.004). The prevalence of HRHPV was 88.9% in VSCC patients and 100.0% in high-grade squamous intraepithelial lesion patients. HPV16 was the most common (52.6%) genotype. The clinical features of neoplasia were similar to those of NNL. Conclusion: VSCC was significantly more common among women aged ≥ 40 years. HRHPV in VSCC and high-grade squamous intraepithelial lesions was high. Women with vulvar lesions, especially those aged > 40 years, should be evaluated for vulvar cancer. Young girls should be vaccinated to prevent vulvar cancer.

Comparison of the Causes of Death Identified Using Automated Verbal Autopsy and Complete Autopsy among Brought-in-Dead Cases at a Tertiary Hospital in Sub-Sahara Africa.

BACKGROUND: Over one-third of deaths recorded at health facilities in Zambia are brought in dead (BID) and the causes of death (CODs) are not fully analyzed. The use of automated verbal autopsy (VA) has reportedly determined the CODs of more BID cases than the death notification form issued by the hospital. However, the validity of automated VA is yet to be fully investigated. OBJECTIVES: To compare the CODs identified by automated VA with those by complete autopsy to examine the validity of a VA tool. METHODS: The study site was the tertiary hospital in the capital city of Zambia. From September 2019 to January 2020, all BID cases aged 13 years and older brought to the hospital during the daytime on weekdays were enrolled in this study. External COD cases were excluded. The deceased's relatives were interviewed using the 2016 World Health Organization VA questionnaire. The data were analyzed using InterVA, an automated VA tool, to determine the CODs, which were compared with the results of complete autopsies. RESULTS: A total of 63 cases were included. The CODs of 50 BID cases were determined by both InterVA and complete autopsies. The positive predictive value of InterVA was 22%. InterVA determined the CODs correctly in 100% cases of maternal CODs, 27.5% cases of noncommunicable disease CODs, and 5.3% cases of communicable disease CODs. Using the three broader disease groups, 56.0% cases were classified in the same groups by both methods. CONCLUSION: While the positive predictive value was low, more than half of the cases were categorized into the same broader categories. However, there are several limitations in this study, including small sample size. More research is required to investigate the factors leading to discrepancies between the CODs determined by both methods to optimize the use of automated VA in Zambia.

Epstein-Barr Virus, But Not Human Papillomavirus, Is Associated With Preinvasive and Invasive Ocular Surface Squamous Neoplasias in Zambian Patients.

Background: The etiopathogenesis of ocular surface squamous neoplasia (OSSN) is not fully understood. We assessed the frequency of oncogenic viruses in OSSN by immunohistochemistry (IHC) and polymerase chain reaction (PCR) for human papillomavirus (HPV), Epstein-Barr virus (EBV), Merkel cell polyomavirus (MCPyV), Kaposi sarcoma virus, and adenovirus. Cases from Zambia were prospectively enrolled using a cross-sectional study design between November 2017 and March 2020. Methods: Demographic and clinical data [age, sex, HIV status, antiretroviral therapy (ART) history, CD4 count, plasma viral load] and tumor biopsies were collected from 243 consenting patients. Tumor samples were bisected, and half was used for DNA isolation, while the other half was formalin fixed and paraffin embedded (FFPE) for histopathology analysis. The expressions of latent EBV nuclear antigen 1 (EBNA1), CDKN2A/p16INK4A (p16), and MCPyV large T-antigen (LT) were tested by IHC. Multiplex PCR was used to detect 16 HPV genotypes and four other DNA tumor viruses [Kaposi's sarcoma-associated herpesvirus (KSHV), EBV, MCPyV, and adenovirus]. Relationships between HIV status, viral DNA and protein expression, and tumor grades were determined by statistical analysis. Results: OSSN tumors from patients were 29.6% preinvasive and 70.4% invasive. Patients presented with unilateral tumors that were 70.4% late stage (T3/T4). OSSN patients were HIV positive (72.8%). IHC on 243 FFPE biopsies resulted in the detection of EBNA1 (EBV), p16 high-risk HPV (HR-HPV), and MCPyV LT expression in 89.0%, 4.9%, and 0.0%, respectively. EBNA1 was expressed in all grades of preinvasive [cornea-conjunctiva intraepithelial neoplasia (CIN)1, 100%; CIN2, 85.7%; CIN3, 95.8%; and carcinoma in situ (CIS), 83.8%] and in invasive (89.2%) OSSN. PCR on 178 samples detected EBV, HR-HPV, and MCPyV in 80.3%, 9.0%, and 13.5% of tumors, respectively. EBV was detected in all grades of preinvasive and invasive OSSN. EBV detection was associated with high HIV viral loads (p = 0.022). HR-HPV was detected in 0.0% CIN1, 0.0% CIN2, 5.6% CIN3, 13.0% CIS, and 7.0% invasive OSSN. Conclusions: Our findings of EBV DNA and EBNA1 protein in all the grades of preinvasive and especially invasive OSSN are consistent with a potential causal role for EBV in OSSN. A role of HPV in OSSN was not clearly established in this study.

Multivariate genomic analysis and optimal contributions selection predicts high genetic gains in cooking time, iron, zinc, and grain yield in common beans in East Africa.

Common bean (Phaseolus vulgaris L.) is important in African diets for protein, iron (Fe), and zinc (Zn), but traditional cultivars have long cooking time (CKT), which increases the time, energy, and health costs of cooking. Genomic selection was used to predict genomic estimated breeding values (GEBV) for grain yield (GY), CKT, Fe, and Zn in an African bean panel of 358 genotypes in a two-stage analysis. In Stage 1, best linear unbiased estimates (BLUE) for each trait were obtained from 898 genotypes across 33 field trials in East Africa. In Stage 2, BLUE in a training population of 141 genotypes were used in a multivariate genomic analysis with genome-wide single nucleotide polymorphism data from the African bean panel. Moderate to high genomic heritability was found for GY (0.45 ± 0.10), CKT (0.50 ± 0.15), Fe (0.57 ± 0.12), and Zn (0.61 ± 0.13). There were significant favorable genetic correlations between Fe and Zn (0.91 ± 0.06), GY and Fe (0.66 ± 0.17), GY and Zn (0.44 ± 0.19), CKT and Fe (-0.57 ± 0.21), and CKT and Zn (-0.67 ± 0.20). Optimal contributions selection (OCS), based on economic index of weighted GEBV for each trait, was used to design crossing within four market groups relevant to East Africa. Progeny were predicted by OCS to increase in mean GY by 12.4%, decrease in mean CKT by 9.3%, and increase in mean Fe and Zn content by 6.9 and 4.6%, respectively, with low achieved coancestry of 0.032. Genomic selection with OCS will accelerate breeding of high-yielding, biofortified, and rapid cooking African common bean cultivars.

Post-mortem examination of Hospital Inpatient COVID-19 Deaths in Lusaka, Zambia - A Descriptive Whole-body Autopsy Series.

BACKGROUND: Since information on the pathology of COVID-19 from sub-Saharan Africa (SSA) remains scarce, the objective of our study was to define the gross pathology and histological features of COVID-19. We report data from 29 whole-body autopsies of COVID-19 deaths occurring in hospitals in Lusaka, Zambia - the first large autopsy case series from Africa. METHODS: We performed a descriptive post-mortem examination study of inpatient COVID-19 related deaths at two hospitals in Lusaka, Zambia. Whole-body autopsies were conducted according to Standard Operating Procedures. Gross and histopathological examinations of all organs were performed. Patient demographics, history, co-morbidities, autopsy gross and microscopic findings, and cause(s) of death were recorded and analyzed using STATA version 14. Variables were grouped and presented as frequencies and percentages. FINDINGS: Autopsies were performed on 29 decedents (mean age = 44 ± 15.8years; age range = 19-82; 17/29 [58.8%] males). 22/29 [75.9%] cases were <55 years of age. A spectrum of pathological manifestations of COVID-19 were seen in all organs. The commonest causes of death were pulmonary thromboembolism (13/29, 45%), Diffuse Alveolar Damage (9/29, 31%), and COVID-19 pneumonia (7/29, 25%). 22/29 (76%) had co-morbidities. Common co-morbidities included HIV (8/29, 28%), Hypertension (6/29, 20%) Tuberculosis (3/29, 10%), Diabetes (3/29, 10%). CONCLUSIONS: A spectrum of gross anatomical and histopathological findings are seen in COVID-19 deaths in hospitalized decedents. These appear broadly similar to those reported from China, Europe and USA. Differences include a younger age group, and co-morbidities of HIV and TB co-infection which require further investigation.

Clinical and Pathologic Presentation of Primary Ocular Surface Tumors among Zambians.

AIM: This study aimed to characterize the clinical and pathologic presentation of ocular surface tumors (OSTs) and to more precisely differentiate the grades of ocular surface squamous neoplasia (OSSN) and benign lesions among Zambians. METHODS: Two-hundred sixty-five Zambian patients presenting with ocular surface growths, suspicious for OSSN, were recruited between November 2017 and November 2019 to a cross-sectional study to investigate their lesions. Sociodemographic data were collected, HIV infection status and vision tests were performed, and lesions were measured and documented. Lesions >2 mm in diameter were excised and sent for pathology analysis. In addition to the biopsies, tears, blood, and buccal swabs were collected. CD4+ T-cell counts were measured by flow cytometry. Lesions were classified according to the WHO guidelines. χ2 and bivariate correlations were used to analyze variable associations and strengths with phi/Cramer's V and correlation coefficients, respectively. Binary logistics was used to adjust for covariance. RESULTS: In this study, 68.3% of the participants were found to be HIV positive. The most frequent diagnoses were invasive OSSN (45.3%), preinvasive OSSN (29.1%), and pterygium (22.6%). Invasive OSSN comprised keratinizing squamous cell carcinoma (SCC) (87.5%), basaloid SCC (3.3%), and spindle cell carcinoma (3.3%). Unusual carcinomas, not described previously, included hybrid SCC (5.0%) and acantholytic SCC (0.8%). Invasive OSSN had advanced tumor (T3/T4) staging (93.3%) at diagnosis. Lymphadenopathy was rare (2.3%), and metastasis was absent. Patients were mostly female (59.2%). Median age was 36 (interquartile ranges 33-41) years (ranges 18-81). Patients with invasive OSSN were more likely to present with pain (p = 0.007), redness (p = 0.034), excessive tearing (p = 0.0001), discharge (p = 0.011), bleeding (p = 0.007), reduced vision (p = 0.0001), fungating lesion (p = 0.001), and blindness (p = 0.005); location at temporal limbus (p = 0.0001), inferior limbus (p = 0.0001), or circumlimbal (p = 0.001); and extension to cornea (p = 0.006) and forniceal palpebral conjunctiva (p = 0.001). Invasive OSSN was associated with any smoking habit and alcohol consumption (p = 0.04 and 0.03, respectively). HIV positivity was strongly associated with OSSN (74.6% OSSN vs. 49.3% benign lesions; p = 0.0001; phi: 0.237 [p = 0.0001]). CONCLUSION: OSTs are very common in Zambia and are strongly associated with HIV coinfection. Patients with OSSN were more likely to be HIV positive than those with pterygia. Despite the commonality of OSTs in sub-Saharan Africa, these cancers have historically been poorly characterized.

High prevalence of pre-existing serological cross-reactivity against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in sub-Saharan Africa.

OBJECTIVE: Significant morbidity and mortality have occurred in the USA, Europe, and Asia due to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), whereas the numbers of infections and deaths in sub-Saharan Africa (SSA) have remained comparatively low. It has been hypothesized that exposure of the population in SSA to other coronaviruses prior to the COVID-19 pandemic resulted in some degree of cross-protection against SARS-CoV-2 infection and pathogenesis. We evaluated this hypothesis by comparing SARS-CoV-2 cross-reactive antibodies in pre-pandemic plasma samples collected from SSA and the USA. METHOD: Pre-COVID-19 pandemic plasma samples from SSA and the USA were collected and tested by immunofluorescence assay against the spike and nucleocapsid proteins of all known human coronaviruses (HCoVs). RESULTS: The prevalence of SARS-CoV-2 serological cross-reactivity was significantly higher in samples from SSA compared with the USA. Most of these cross-reactive samples cross-recognized the SARS-CoV-2 nucleocapsid protein and the spike proteins of other HCoVs. Nucleocapsid proteins from HCoV-NL63 and HCoV-229E were detected in most samples, thereby implicating prior exposure to these two HCoVs as the likely source of cross-reactive antibodies against SARS-CoV-2. CONCLUSION: The low incidences of SARS-CoV-2 infection and disease in SSA appear to be correlated with the pre-pandemic serological cross-recognition of HCoVs, which are substantially more prevalent in SSA than the USA.

Molecular profiling of gastric cancer in a population with high HIV prevalence reveals a shift to MLH1 loss but not the EBV subtype.

The human immunodeficiency virus (HIV) pandemic heavily affects sub-Saharan Africa. It is associated with persistently active Epstein-Barr virus (EBV) infection. To determine if this translates into increased frequency of EBV-associated gastric cancer (EBVaGC), we evaluated molecular profiles of gastric cancer (GC) in Zambia. Patients with GC or premalignant gastric lesions were enrolled in Lusaka, Zambia. We used patients without any of these lesions as a control group. Chromogenic in situ hybridization (CISH) on tumor tissue was used to identify EBVaGC. To identify the microsatellite unstable subtype, immunofluorescence staining for MutL homolog 1 (MLH1) was used. Exposure to EBV and HIV was assessed serologically. We enrolled 369 patients (median age 52 years [IQR 41-65]; 198 (54%) female). Of these, 72 (20%) had GC and 35 (9%) had gastric premalignant lesions (PL). CISH identified EBVaGC in 5/44 (11%) of those with adequate tissue, while MLH1 loss was identified in 29/45 (64%). Both GC and PL were associated with the highest titers of antibodies to Early antigen-diffuse (OR 2.5, 95% CI 1.0-6.1, P = .048 and OR 3.9, 95% CI 1.1-12.9, P = .03, respectively) at high concentrations. Human immunodeficiency virus infection was associated with a range of antibodies to EBV, but not with any cancer subtype. Despite the association of HIV with persistent EBV, the proportion of EBVaGC in Zambia is similar to populations with a low prevalence of HIV infection. The proportion of microsatellite unstable tumors may be higher than other populations.

Human epidermal growth factor receptor 2 overexpression in gastric and gastroesophageal junction adenocarcinoma in patients seen at the University Teaching Hospital, Lusaka, Zambia.

BACKGROUND: There are scanty data on the occurrence of gastric tumours overexpressing human epidermal growth factor receptor 2 (HER2) in Africa. OBJECTIVE: To assess HER2 protein overexpression in gastric and gastroesophageal junction adenocarcinoma (GGEAC) samples from a single centre in Zambia. METHODOLOGY: This was a cross-sectional study of formalin-fixed paraffin-embedded blocks with GGEAC. Prepared slides were first stained with Haematoxylin and Eosin and then evaluated for HER2 protein overexpression by immunohistochemistry. RESULTS: A total of 57 gastric tissues were stained and evaluated for HER2 overexpression. Thirteen (23%) showed overexpression, 41/57 (72%) had negative and 3/57 (5%) had equivocal staining. The equivocal cases were excluded from the final analysis. Of the remaining 54 tissues, 28 (52%) were from females, and 26 (48%) were from males. The mean age was 59 years (SD 15 years). HER2 overexpression was highest in moderately differentiated tumours (p=0.0005). Intestinal type tumours had a higher occurrenc of HER2 overexpression than diffuse or mixed sub-types (p=0.0087). HER2 overexpression was not associated with age (p=0.27), sex (p=1.00) or anatomical location (p=1.00). CONCLUSION: The occurrence of GGEAC HER2 overexpression in Zambian patients is similar to proportions reported elsewhere, and it is associated with moderately differentiated tumours of the intestinal type.

Brain is a potential sanctuary for subtype C HIV-1 irrespective of ART treatment outcome.

Subtype C HIV-1 is responsible for the largest proportion of people living with HIV-1 infection. However, there is limited information about the roles of the brain and its cell types as a potential sanctuary for this subtype and how the sanctuary may be affected by the administration of anti-retroviral therapy (ART). To address this issue, we collected postmortem brain tissues from ART treated HIV-1 infected Zambian individuals who experienced complete viral suppression and those who did not. Tissues from various brain compartments were collected from each individual as frozen and formalin-fixed paraffin embedded brain specimens, for detection and quantification of HIV-1 genomes and identification of the infected cell type. Genomic DNA and RNA were extracted from frozen brain tissues. The extracted DNA and RNA were then subjected to droplet digital PCR for HIV-1 quantification. RNA/DNAscope in situ hybridization (ISH) for HIV-1 was performed on formalin-fixed paraffin embedded brain tissues in conjugation with immunohistochemistry to identify the infected cell types. Droplet digital PCR revealed that HIV-1 gag DNA and RNA were detectable in half of the cases studied regardless of ART success or failure. The presence of HIV-1 lacked specific tissue compartmentalization since detection was random among various brain tissues. When combined with immunohistochemistry, RNA/DNAscope ISH demonstrated co-localization of HIV-1 DNA with CD68 expressing cells indicative of microglia or peripheral macrophage. Our study showed that brain is a potential sanctuary for subtype C HIV-1, as HIV-1 can be detected in the brain of infected individuals irrespective of ART treatment outcome and no compartmentalization of HIV-1 to specific brain compartments was evident.

Function-associated surface molecules on airway dendritic cells in cigarette smokers.

Airway dendritic cells (DCs) control pulmonary immune responses to inhaled particles. However, the profile of function-associated surface molecules on airway DCs in smokers is unknown. In this study, function-associated surface molecules were analyzed using four-color flow cytometry on myeloid DCs (mDCs) in bronchoalveolar lavage fluid (BALF) of cigarette smokers and never-smokers. Furthermore, the lung function was assessed directly before bronchoscopy in all participants. There was a 7-fold increase in total cell numbers in BALF of smokers, as compared with never-smokers. The percentage of mDCs among BALF cells and the expression of the maturation marker CD83 on mDCs did not differ between smokers and never-smokers. However, there was a strong increase in the expression of Langerin and CD1a (markers of Langerhans cells) on mDCs of smokers. Furthermore, mDCs of smokers were characterized by an increased expression of antigen presentation markers such as CD80 and CD86. By contrast, mDCs of smokers displayed a decreased expression of the lymph node homing receptor CCR7, as compared with mDCs of never-smokers. Decreased expression of CCR7 on mDCs, but not any of the other surface molecules studied, was specifically associated with airway obstruction and pulmonary hyperinflation in smokers. In conclusion, our data suggest that smoking affects the expression profile of function-associated surface molecules on airway mDCs. We provide the first evidence that a reduced CCR7 expression on airway mDCs is associated with airflow limitation in smokers.

Safety of segmental allergen challenge in human allergic asthma.

BACKGROUND: Segmental allergen challenge is widely used to study mechanisms of human allergic asthma. Despite the relatively large dissemination, limited information is available about the safety of this method. OBJECTIVE: Observational, retrospective study to report the adverse events of segmental allergen challenge in a large group of volunteers with asthma. METHODS: In total, 78 cases from several studies performed between 1994 and 2007 were pooled for this analysis. Volunteers underwent allergen challenge using either a fixed dose of allergen (7 cases) or an individually standardized allergen dose defined by an inhaled allergen test before the challenge (71 cases). A subgroup of 13 volunteers underwent repeated challenges, with more than 6 months between the challenges. RESULTS: With a fixed dose instilled during bronchoscopy, 43% of the participants developed wheezing and coughing, requiring 2-6 puffs of a ss(2)-agonist after segmental allergen challenge. In volunteers with individually standardized doses, a ss(2)-agonist was required in only 19% of the cases. No severe adverse events occurred in all cases studied. Volunteers who underwent repeated challenges did not develop more adverse events than those who underwent 1 challenge. CONCLUSIONS: Segmental allergen challenge is a safe tool to study the mechanisms of human allergic asthma, even when repeated challenges are performed in the same patient. It is associated with only a few, tolerable adverse events, especially when the dose of allergen is standardized individually.