Impaired response to HBV vaccination in HIV-1 infected children : immunopathological mechanisms

HBV vaccination prevents HBV infection and related liver cancer. Immunological dysfunctions of Tfh and B cells in HIV-1 infected individuals may affect the response to HBV vaccine. The general objective of this thesis was to elucidate HBV vaccine response in HIV-1 infected children receiving ART, to assess functional and phenotypic properties of pTfh cells in HBV vaccinated children and to study whether HBV vaccination may have a role in reducing the size of HIV-1 reservoirs. In paper I, we showed reduced frequencies of pTfh cells in HIV-1 infected children compared to healthy controls and of pTfh cells expressing the co-stimulatory molecules ICOS and PD1, important to mediate the interaction of Tfh cells with B cells. The frequency of IL-4 expressing pTfh cells and of resting memory B cells was also lower in infected children; on the contrary, an expansion of exhausted memory B cells was detected in this group. In paper II, all children who received HBV vaccination, except four, displayed a strong vaccine response at 1 month post-vaccination. Lower plasma levels of anti-HBs antibodies (Abs) were measured in HIV-1 infected children compared to controls at 1 month and 6 months post-vaccination. HIV-1 infected children had elevated plasma CXCL13 levels compared to controls at all time points; changes in plasma CXCL13 concentration were however not observed following vaccination. As the functional and phenotypic properties of pTfh cells were similar in both groups pre- and postvaccination, alterations in pTfh properties could not explain the reduced vaccine response in HIV-1 infected children. In a yet unpublished study, we showed an altered frequency of B cell subsets in HIV-1 infected children which correlated with anti-HBs Ab titers after vaccination. In paper III, the number of HIV-1 DNA copies in PBMCs was unchanged after vaccination with a combined HBV and HAV vaccine in HIV-1 infected children; however, 54% of these individuals showed a decline in the size of HIV-1 DNA reservoir after vaccination. The change was most likely related to vaccination since the children were on ART for a median of 7.2 years and had therefore likely reached a plateau phase for HIV-1 DNA decay after ART initiation. EM CD8+ T cells were the stronger predictors of the change in HIV-1 DNA copies using multivariate analysis. In conclusion, three doses of accelerated HBV vaccination induced high anti-HBs Abs in both HIV-1 infected and control children. A rapid decline of anti-HBs Abs in plasma after 6 months from vaccination suggests the need of an additional booster dose for HBV vaccine. The role of HBV vaccination in reducing HIV-1 DNA reservoirs should be investigated further

Assessments of Major Cereal Disease in Potential Agro-Ecology of Borana Zone , Southern Oromia

Cereal Production in Borana lowland and Mid highland were threatened by a number of biotic and abiotic factors. Among these biotic factors diseases were the prominent one. Therefore, these survey work was conducted in Borana administrative zone , to determine the incidence and severity of major cereal disease and to identify areas of intervention for optimization of cereal productivity. Eighteen site, which represent the two agro-ecologica1 zones were surveyed. Six representative crop producing districts of the zone were selected based on the agro-ecology of the zone. From this six districts 18 PAs were purposively selected. From one district three PAs were assessed from each PA 10 fields were surveyed at an interval of 5-10 km . The main cereals grown in these areas were maize , Tef wheat barley and sorghum. From these major cereal crop most frequently six different types of disease were identified these diseases were GLS, Rusts, Fusarium head scab of wheat Loose smut, Northern maize blight (Turcicum leaf blight) and Maize ear rots. In all the surveyed area all these disease were prevalent, However, the extent of the economic damage varies depending on factors such as production systems, climate, choice of variety. Disease problem is less feared in miyo and Yabello as compared to fear of the rainfall shortage. At Teltale loose smut disease of sorghum, tef and barley were significantly important . While the incidence and disease severity is less than 20 % in lowland (rainfall deficit areas) except loose smut at Teltale. While disease are the most economically important in all the rests of the districts. Therefore these survey results open the doors for the estimation of economic loss caused by these identified disease on the major cereal at Abaya, Galana and Bule hora. In Mid highland areas of the zone foliar disease like turcicum leaf blight, leaf rust and grey leaf spots are among the challenging disease of maize, in addition to this crop wheat is one of the important cereal crops of mid highland which were highly affected by rust and Fusarium head scab disease. However, in 2014 no disease was assessed from lowland due to the failurity of the crop before reaching the flowering stages. Keywords: Cereal diseas

Increased activated memory B-cells in the peripheral blood of patients with erythema nodosum leprosum reactions.

B-cells, in addition to antibody secretion, have emerged increasingly as effector and immunoregulatory cells in several chronic inflammatory diseases. Although Erythema Nodosum Leprosum (ENL) is an inflammatory complication of leprosy, the role of B- cell subsets has never been studied in this patient group. Therefore, it would be interesting to examine the contribution of B-cells in the pathogenesis of ENL. A case-control study design was used to recruit 30 untreated patients with ENL and 30 non-reactional lepromatous leprosy (LL) patient controls at ALERT Hospital, Ethiopia. Peripheral blood samples were obtained before, during and after treatment from each patient. Peripheral blood mononuclear cells (PBMCs) were isolated and used for immunophenotyping of B- cell subsets by flow cytometry. The kinetics of B-cells in patients with ENL before, during and after Prednisolone treatment of ENL was compared with LL patient controls as well as within ENL group. Total B-cells, mature B-cells and resting memory B-cells were not significantly different between patients with ENL reactions and LL controls before treatment. Interestingly, while the percentage of naive B-cells was significantly lower in untreated ENL patients than in LL patient controls, the percentage of activated memory B-cells was significantly higher in these untreated ENL patients than in LL controls. On the other hand, the percentage of tissue-like memory B-cells was considerably low in untreated ENL patients compared to LL controls. It appears that the lower frequency of tissue-like memory B-cells in untreated ENL could promote the B-cell/T-cell interaction in these patients through downregulation of inhibitory molecules unlike in LL patients. Conversely, the increased production of activated memory B-cells in ENL patients could imply the scale up of immune activation through antigen presentation to T-cells. However, the generation and differential function of these memory B-cells need further investigation. The finding of increased percentage of activated memory B-cells in untreated patients with ENL reactions suggests the association of these cells with the ENL pathology. The mechanism by which inflammatory reactions like ENL affecting these memory cells and contributing to the disease pathology is an interesting area to be explored for and could lead to the development of novel and highly efficacious drug for ENL treatment

The Effects of Prednisolone Treatment on Cytokine Expression in Patients with Erythema Nodosum Leprosum Reactions.

Erythema nodosum leprosum (ENL) is a systemic inflammatory complication occurring mainly in patients with lepromatous leprosy (LL) and borderline lepromatous leprosy. Prednisolone is widely used for treatment of ENL reactions but clinical improvement varies. However, there is little good in vivo data as to the effect of prednisolone treatment on the pro-inflammatory cytokines in patients with ENL reactions. As a result, treatment and management of reactional and post-reactional episodes of ENL often pose a therapeutic challenge. We investigated the effect of prednisolone treatment on the inflammatory cytokines TNF, IFN-γ, IL-1β, IL-6, and IL-17 and the regulatory cytokines IL-10 and TGF-β in the skin lesion and blood of patients with ENL and compared with non-reactional LL patient controls. A case-control study was employed to recruit 30 patients with ENL and 30 non-reactional LL patient controls at ALERT Hospital, Ethiopia. Blood and skin biopsy samples were obtained from each patient before and after prednisolone treatment. Peripheral blood mononuclear cells from patients with ENL cases and LL controls were cultured with M. leprae whole-cell sonicates (MLWCS), phytohemagglutinin or no stimulation for 6 days. The supernatants were assessed with the enzyme-linked immunosorbent assay for inflammatory and regulatory cytokines. For cytokine gene expression, mRNA was isolated from whole blood and skin lesions and then reverse transcribed into cDNA. The mRNA gene expression was quantified on a Light Cycler using real-time PCR assays specific to TNF, IFN-γ, IL-β, TGF-β, IL-17A, IL-6, IL-8, and IL-10. The ex vivo production of the cytokines: TNF, IFN-γ, IL-1β, and IL-17A was significantly increased in untreated patients with ENL. However, IL-10 production was significantly lower in untreated patients with ENL and significantly increased after treatment. The ex vivo production of IL-6 and IL-8 in patients with ENL did not show statistically significant differences before and after prednisolone treatment. The mRNA expression in blood and skin lesion for TNF, IFN-γ, IL-1β, IL-6, and IL-17A significantly reduced in patients with ENL after treatment, while mRNA expression for IL-10 and TGF-β was significantly increased both in blood and skin lesion after treatment. This is the first study examining the effect of prednisolone on the kinetics of inflammatory and regulatory cytokines in patients with ENL reactions before and after prednisolone treatment. Our findings suggest that prednisolone modulates the pro-inflammatory cytokines studied here either directly or through suppression of the immune cells producing these inflammatory cytokines

Diversity of Mycobacterium tuberculosis

Understanding the genetic diversity of Mycobacterium tuberculosis is needed for a better understanding of the epidemiology of TB and could have implications for the development of new diagnostics, drugs, and vaccines. M. tuberculosis isolates were characterized using spoligotyping and were compared with the SpoIDB4 database of the Pasteur Institute of Guadeloupe. A total of 53 different patterns were identified among 192 isolates examined. 169 of the isolates were classified into one of the 33 shared SITs, whereas the remaining 23 corresponded to 20 orphan patterns. 54% of the isolates were ascribed to the T family, a family which has not been well defined to date. Other prominent families were CAS, Haarlem, LAM, Beijing, and Unknown comprising 26%, 13%, 2.6%, 0.5%, and 2.1%, respectively. Among HIV-positive patients, 10 patterns were observed among 25 isolates. The T (38.5%), H (26.9%), and CAS (23.1%) families were the most common among HIV-positive individuals. The diversity of the M. tuberculosis strains found in this study is very high, and there was no difference in the distribution of families in HIV-positive and HIV-negative TB patients except the H family. Tuberculosis transmission in Addis Ababa is due to only the modern M. tuberculosis families (CAS, LAM, T, Beijing, Haarlem, and U)

Peptides Derived from Mycobacterium leprae ML1601c Discriminate between Leprosy Patients and Healthy Endemic Controls

The stable incidence of new leprosy cases suggests that transmission of infection continues despite worldwide implementation of MDT. Thus, specific tools are needed to diagnose early stage Mycobacterium leprae infection, the likely sources of transmission. M. leprae antigens that induce T-cell responses in M. leprae exposed and/or infected individuals thus are major targets for new diagnostic tools. Previously, we showed that ML1601c was immunogenic in patients and healthy household contacts (HHC). However, some endemic controls (EC) also recognized this protein. To improve the diagnostic potential, IFN-γ responses to ML1601c peptides were assessed using PBMC from Brazilian leprosy patients and EC. Five ML1601c peptides only induced IFN-γ in patients and HHC. Moreover, 24-hour whole-blood assay (WBA), two ML1601c peptides could assess the level of M. leprae exposure in Ethiopian EC. Beside IFN-γ, also IP-10, IL-6, IL-1β, TNF-α, and MCP-1 were increased in EC from areas with high leprosy prevalence in response to these ML1601c peptides. Thus, ML1601c peptides may be useful for differentiating M. leprae exposed or infected individuals and can also be used to indicate the magnitude of M. leprae transmission even in the context of various HLA alleles as present in these different genetic backgrounds

Protection from COVID-19 disease in hamsters vaccinated with subunit SARS-CoV-2 S1 mucosal vaccines adjuvanted with different adjuvants

IntroductionAdjuvant plays an important role in directing the immune responses induced by vaccines. In previous studies, we have shown that a mucosal SARS-CoV-2 S1 subunit vaccine adjuvanted with a combination of CpG, Poly I:C and IL-15 (named CP15) induced effective mucosal and systemic immunity and conferred nearly sterile protection against SARS-CoV-2 viral replication in macaque models.MethodsIn this study, we used a hamster model, which mimics the human scenario and reliably exhibits severe SARS-CoV-2 disease similar to hospitalized patients, to investigate the protection efficacy of the vaccines against COVID-19 disease. We compared the weight loss, viral loads (VLs), and clinical observation scores of three different vaccine regimens. All three regimens consisted of priming/boosting with S1 subunit vaccines, but adjuvanted with alum and/or CP15 administrated by either intramuscular (IM) or intranasal (IN) routes: Group 1 was adjuvanted with alum/alum administrated IM/IM; Group 2 was alum-IM/CP15-IN; and Group 3 was CP15-IM/CP15-IN.ResultsAfter challenge with SARS-CoV-2 WA strain, we found that the alum/CP15 group showed best protection against weight loss, while the CP15 group demonstrated best reduction of oral SARS-CoV-2 VLs, suggesting that the protection profiles were different. Sex differences for VL and clinical scores were observed. Humoral immunity was induced but not correlated with protection. Moreover, S1-specific binding antibody titers against beta, omicron BA.1, and BA.2 variants showed 2.6-, 4.9- and 2.8- fold reduction, respectively, compared to the Wuhan strain.DiscussionOverall, the data suggested that adjuvants in subunit vaccines determine the protection profiles after SARS-CoV-2 infection and that nasal/oral mucosal immunization can protect against systemic COVID-19 disease

Epidemiology of rubella virus cases in the pre-vaccination era of Ethiopia, 2009–2015

Abstract Background Rubella is a common mild rash illness caused by rubella virus. The majority of infections occur in children and young adults. The infection is the cause of a serious birth defect known as Congenital Rubella Syndrome (CRS) when a woman acquires infection early in pregnancy. Ethiopia has not yet established rubella virus surveillance and has not yet introduced rubella vaccine into the routine immunization program. We characterize the epidemiology of laboratory confirmed rubella virus cases collected through measles surveillance from 2009 to 2015 to better understand the burden of the disease in the country. Methods A descriptive analysis was made to characterize rubella cases reported through the national measles case based surveillance system. The measles case definition was used to capture potential rubella cases. A suspected measles case was a person with generalized rash and fever with cough, or coryza or conjunctivitis. Those cases whose sera were negative for measles IgM antibodies were tested for rubella IgM antibody. A confirmed rubella case was a person who tested positive for rubella IgM. Only laboratory confirmed rubella cases were analyzed in this article. Results Between 2009 and 2015, a total of 28,284 serum/plasma samples were collected and tested for measles IgM antibody and 11,151 (39.4%) were found positive. A total of 17,066 measles IgM negative or indeterminate samples were tested for rubella virus IgM and 2615 (15.3%) were found positive during the same period. Of 2615 confirmed rubella cases, 52.2% were females. The age of confirmed cases ranged from one month to 42 years with a mean age of 7.3 years. Three-fourth of all confirmed rubella cases were aged less than 10 years. The number of laboratory confirmed rubella cases linearly increased from 83 in 2009 to 856 in 2013 but dropped to 222 and 319 in 2014 and 2015 respectively. Higher number of cases occurred in the hot dry season (January through June) and in the central and western part of Ethiopia with 127 lab-confirmed outbreaks in the study period. Conclusions Based on our analysis, rubella was found to be endemic throughout Ethiopia. Children below the age of 10 years were the most affected. The burden of rubella cases varied from year to year but had a seasonal peak in March. To better understand the magnitude of rubella prior to vaccine introduction, establishing rubella surveillance system, conducting sero-prevalence studies among child bearing age females and establishing CRS sentinel surveillance among young infants are critical

Breast cancer in Ethiopia: evidence for geographic difference in the distribution of molecular subtypes in Africa

Abstract Background Breast cancer is a heterogeneous disease with several morphological and molecular subtypes. Widely accepted molecular classification system uses assessment of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and proliferation marker Ki67. Few studies have been conducted on the incidence and molecular types of breast cancer in Sub-Saharan Africa. Previous studies mainly from Western and Central Africa, showed breast cancer to occur at younger ages and to present with aggressive features, such as high-grade, advanced stage and triple-negative phenotype (negative for ER, PR and HER2). Limited data from East Africa including Ethiopia however shows hormone receptor negative tumors to account for a lower proportion of all breast cancers than has been reported from elsewhere in Africa. Methods In this study from Tikur Anbessa Specialized Hospital, 114 breast cancer patients diagnosed between 2012 and 2015 were enrolled. ER, PR, Ki67 and HER2 receptor status were assessed using immunohistochemistry from tissue microarrays. FISH was used for assessment of gene amplification in all equivocal tumor samples and for confirmation in HER2-enriched cases. Results The distribution of molecular subtypes was: Luminal A: 40%; Luminal B: 26%; HER2-enriched: 10%; TNBC: 23%. ER were positive in 65% of all tumors and 43% the cases were positive for PR. There was statistically significant difference in median age at diagnosis between the molecular subtypes (P < 0.05). There was a bimodal distribution of molecular subtypes in different age ranges with Luminal B subtype being more common at younger ages (median = 36) and Luminal A subtype more prevalent at older ages (median = 42). There were no statistically significant differences in tumor grade, histology, and stage between the molecular subtypes of breast cancer. Conclusion The present study detected Luminal A breast cancer to be the most common subtype and reveals a relatively low rate of hormone receptor negative and TNBC. Our findings and results from other East African studies suggest geographic variability in the distribution of the molecular subtypes of breast cancer in Africa and hence have important clinical and policy implications for breast cancer control and treatment in Ethiopia.https://deepblue.lib.umich.edu/bitstream/2027.42/142374/1/12905_2018_Article_531.pd

Clinical and Socio-demographic Profile of the First 33 COVID-19 Cases Treated at Dedicated Treatment Center in Ethiopia

BACKGROUND:Severe respiratory tract infection caused by family of Corona viruses has become world pandemic. The purpose of this study was to describe the first few COVID 19 cases in Ethiopia.METHOD: Descriptive study was conducted on the first 33 consecutive RT-PCR confirmed COVID 19 cases diagnosed and managed at Ekka-Kotebe COVID Treatment Center in Addis Ababa, Ethiopia.RESULT: The median age of the cases was 36 years. Cough, headache and fever were the most frequent symptoms. Diarrhea, sore throats, loss of taste and/or smell sensation were among the rare symptoms. Most (84.8%) had mild to moderate disease, and 15.2%(n=5) were critical at the time of admission. Among the five ICU admissions, four patients required invasive mechanical ventilation. Thirty cases were discharged after two pairs of nasopharyngeal and oropharyngeal samples turned negative for SARS CoV2. Three cases from the ICU died while on mechanical ventilator. The age of the two deaths was 65 years, and one was 60 years. With the exception of three, all cases were either imported from abroad or had contact with confirmed cases.CONCLUSION: Most of our patients were in the younger age group with male predominance and few with comorbidities. Cough was the commonest symptom followed by headache and fever. As it was in the early stage of the pandemic, observation of more cases in the future will reveal further clinical and demographic profiles of COVID-19 cases in Ethiopia