Comparative Performance of Serological (IgM/IgG) and Molecular Testing (RT-PCR) of COVID-19 in Three Private Universities in Cameroon during the Pandemic.

BACKGROUND: COVID-19 remains a rapidly evolving and deadly pandemic worldwide. This necessitates the continuous assessment of existing diagnostic tools for a robust, up-to-date, and cost-effective pandemic response strategy. We sought to determine the infection rate (PCR-positivity) and degree of spread (IgM/IgG) of SARS-CoV-2 in three university settings in Cameroon Method: Study volunteers were recruited from November 2020 to July 2021 among COVID-19 non-vaccinated students in three Universities from two regions of Cameroon (West and Centre). Molecular testing was performed by RT-qPCR on nasopharyngeal swabs, and IgM/IgG antibodies in plasma were detected using the Abbott Panbio IgM/IgG rapid diagnostic test (RDT) at the Virology Laboratory of CREMER/IMPM/MINRESI. The molecular and serological profiles were compared, and p < 0.05 was considered statistically significant. RESULTS: Amongst the 291 participants enrolled (mean age 22.59 ± 10.43 years), 19.59% (57/291) were symptomatic and 80.41% (234/291) were asymptomatic. The overall COVID-19 PCR-positivity rate was 21.31% (62/291), distributed as follows: 25.25% from UdM-Bangangte, 27.27% from ISSBA-Yaounde, and 5% from IUEs/INSAM-Yaounde. Women were more affected than men (28.76% [44/153] vs. 13.04% [18/138], p < 0.0007), and had higher seropositivity rates to IgM+/IgG+ (15.69% [24/153] vs. 7.25% [10/138], p < 0.01). Participants from Bangangté, the nomadic, and the "non-contact cases" primarily presented an active infection compared to those from Yaoundé (p= 0.05, p = 0.05, and p = 0.01, respectively). Overall IgG seropositivity (IgM-/IgG+ and IgM+/IgG+) was 24.4% (71/291). A proportion of 26.92% (7/26) presenting COVID-19 IgM+/IgG- had negative PCR vs. 73.08% (19/26) with positive PCR, p < 0.0001. Furthermore, 17.65% (6/34) with COVID-19 IgM+/IgG+ had a negative PCR as compared to 82.35% with a positive PCR (28/34), p < 0.0001. Lastly, 7.22% (14/194) with IgM-/IgG- had a positive PCR. CONCLUSION: This study calls for a rapid preparedness and response strategy in higher institutes in the case of any future pathogen with pandemic or epidemic potential. The observed disparity between IgG/IgM and the viral profile supports prioritizing assays targeting the virus (nucleic acid or antigen) for diagnosis and antibody screening for sero-surveys.

Standardised ido-BR1 Cucumber Extract Improved Parameters Linked to Moderate Osteoarthritis in a Placebo-controlled Study.

BACKGROUND: According to the World Health Organization, osteoarthritis (OA) is one of the 10 most disabling diseases in developed countries, with worldwide estimates of 9.6% prevalence in men and 18.0% in women over 60 years old. Its management is not well established and involves the use of high doses of painkillers coupled with anti-inflammatory agents. OBJECTIVE: In the search for alternatives to manage the disease, previous studies have shown superior properties of Q-ActinTM in managing OA-related pain compared with standard treatments. Qactin is a cucumber extract with the anti-inflammatory iminosugar idoBR1 standardised to over 1%. This study investigated the effects of different doses (20 mg, 100 mg) of Q-Actin in a longitudinal placebo-controlled experiment. METHODS: There were 101 patients with knee OA enrolled for the 180-day study, with 91 patients completing it. Patients were grouped into a placebo group (PLBO), as well as a 20mg dose (Q-Actin 1) and 100 mg dose (Q-Actin 2) groups. The PLBO group received cellulose in capsules identical to the Q-Actin capsules. RESULTS: There was a significant improvement in the pain-related parameters over time that was dose-dependent. CONCLUSION: This study clearly demonstrated the effectiveness of Q-Actin compared to placebo in the management of pain related to moderate osteoarthritis.

Epidemiology of Idiopathic Inflammatory Myopathies in Africa: A Contemporary Systematic Review.

BACKGROUND: The epidemiology of idiopathic inflammatory myopathies (IIMs) has been extensively studied in America, Europe, and Asia, but remains unclear in Africa. OBJECTIVE: The aim of this review was to summarize available data on the epidemiology of IIMs in Africa. METHODS: We searched MEDLINE, EMBASE, and African Journals Online for studies published up to December 30, 2020, and reporting epidemiological data on IIMs in Africa. Data were combined through narrative synthesis. The review protocol was registered with PROSPERO, CRD42020186781. RESULTS: We included 39 studies reporting 683 cases (71.7% adults) of IIMs. Incidence rates of ~7.5/1,000,000 person-years and 1.2/1,000,000 person-years were estimated for dermatomyositis (DM), whereas polymyositis (PM) had an incidence rate of 8.8/1,000,000 person-years. Prevalence estimates of 11.49/100,000 and 11/100,000 (95% confidence interval, 0-32) were provided for IIMs and the PM subtype, respectively. Mean age at diagnosis ranged from 7.9 to 57.2 years, and 50% to 100% of the patients were females. Main subtypes of adult-onset IIMs were DM (21%-93%) and PM (12%-79%), whereas the commonest juvenile subtype was juvenile DM (5.8%-9%). Skeletal muscle involvement (56%-100%) was the main disease feature, and esophagus was the most commonly affected internal organ (6%-65.2%). Anti-Jo1/histidyl tRNA synthetase (7%-100%) and anti-Mi2 (17%-45%) antibodies were the most frequent myositis specific antibodies. Early mortality was high (7.8%-45%), and main death causes were infections, cancers and organ damage in respiratory and cardiovascular domains. CONCLUSIONS: Apart from a potential younger age at onset of adult IIMs in Africa, current sparse data mostly suggest a similar epidemiology between Africa and other regions. Further high-quality studies are required to validate these findings.

Epidemiology of Sjögren Syndrome in Africa: A Scoping Review.

BACKGROUND: The epidemiology of Sjögren syndrome (SS) has been extensively studied in America, Europe, and Asia. OBJECTIVE: To summarize available data on the epidemiology of SS in Africa. METHODS: MEDLINE, EMBASE, and African Journals Online were searched from inception up to May 17, 2020, to identify relevant articles. Data gleaned from these reports have been summarized narratively in this review. RESULTS: Twenty-one hospital-based studies were included. These studies reported 744 cases of SS. The mean age at diagnosis varied between 28 and 73.6 years, and the female proportion ranged from 83.3% to 100%. There was no population-based incidence or prevalence. Among people with autoimmune and other rheumatic conditions, the frequency of primary SS was in the range 1.9% to 47.6%, whereas that of rheumatoid arthritis-associated secondary SS was in the range 4.3% to 100%. Sicca symptoms were the commonest features, with most frequently involved organs being joints, lungs, and neurological structures. Main autoantibodies were anti-Ro/SS antigen A, anti-La/SS antigen B, and antinuclear antibodies. CONCLUSIONS: The epidemiology of SS is poorly characterized in Africa. Available data are broadly consistent with those from other populations. Extensive and high-quality research is urgently needed.

Gender difference in the association between gout at diagnosis and metabolic syndrome in African population: a retrospective cohort study.

Introduction: few studies have specifically investigated the link between metabolic syndrome (MetS) and gout in sub-Saharan Africa. This report aimed to evaluate in patients with gout the association between gout at diagnosis and MetS and to assess the gender difference. Methods: we performed a single-centre retrospective cohort study on all outpatients seen in the Rheumatology Unit of the General Hospital, Douala, Cameroon. We included records of patients with a recent diagnosis of gout according to the American College of Radiology (ACR) criteria. MetS was defined according to the harmonized criteria. Results: we included 511 patients (415 men), with a mean age at diagnosis of 55.9 ±10.8 years. Women were older than men. The mean serum uric acid was 8.24±2.23 mg/L, with hyperuricemia found in 394 patients (77.1%). MetS was present in 101 patients (19.7% [95% CI: 16.8%-22.1%]), significantly more common in men compared to women (23.6% vs. 10.8%; p<0.001). The main components of the MetS were: increased waist circumference (217 patients, 61.3%), obesity (256 patients, 52.2%), hypertension (208 patients, 40.7%), and diabetes mellitus (52 patients, 10.2%). Furthermore, hypertension, diabetes mellitus, obesity, and increased waist circumference were more frequent in women (p<0.001). There was no difference in dyslipidemia according to gender. The combination of components of the MetS was more frequent in men than women (p<0.001). Conclusion: MetS are common in newly diagnosed Cameroonian patients with gout, with increased waist circumference, obesity, hypertension and diabetes mellitus being the main components. These components are more common in women, but their combination was more frequent in men.

Systemic lupus erythematosus in Native sub-Saharan Africans: A systematic review and meta-analysis.

BACKGROUND: The prevalence and phenotype of systemic lupus erythematosus (SLE) have not been thoroughly investigated in Native sub-Saharan Africans despite knowledge that the highest burden of SLE occurs in people with an African trait. Through this systematic review of literature and meta-analysis, we wished to fill this gap. METHODS: PubMed, EMBASE, Web of Science, African Journals Online, and Global Index Medicus as well as references of retrieved papers were searched to select studies addressing SLE in Native sub-Saharan Africans and published between January 1, 2008 and October 7, 2018. The prevalence of SLE and its characteristics were pooled through narrative review and random-effects model. Heterogeneity (I2) was assessed via the χ2 test. Pooled estimates are expressed with 95% confidence intervals. This study is registered with PROSPERO: registration number CRD42019139226. RESULTS: Out of 1502 papers, 15 hospital-based studies were included. The pooled prevalence of SLE among 28,575 participants was 1.7% (0.8-2.9), with substantial heterogeneity between studies (I2 = 96.9% [94.8%; 98.1%], τ2 = 0.0020, p < 0.0001). The mean age at diagnosis ranged from 28.8 to 39.2 years. The female proportion varied from 88% to 100%. Rheumatological (5.1%-99.9%), dermatological (4.3%-100%) and hematological (1.4-86.9%) manifestations were the commonest clinical features of SLE. Patients had a high seroprevalence for anti-ribonucleoprotein 57.9% (36.4-77.9), anti-Smith 53.5% (40.4-66.2), anti-Sjogren syndrome antigen A 45.6% (19.2-73.4) and anti-Sjogren syndrome antigen B 33.7% (13.6-57.6) autoantibodies. The most used treatments were corticosteroids 99% (94.9-100) and antimalarials 62. 8% (23.3-94.1). The pooled mortality rate was 10.3% (3.3-20.6) and death was mainly due to infections, kidney disease and neurological involvement. CONCLUSION: Over the last 30 years, SLE was not rare among Native sub-Saharan Africans and its featured characteristics were earlier onset, female predominance, and high seropositivity for extractable nuclear antigen autoantibodies. Corticosteroids and antimalarials were the standard treatments. The mortality rate was high. Population prevalence and incidence as well as full description of SLE characteristics in Native sub-Saharan Africans are needed.

Epidemiological data on systemic lupus erythematosus in native sub-Saharan Africans.

Multiethnic studies conducted outside sub-Saharan Africa identify African Black people as the highest-risk group for morbidity and mortality among the 5,000,000 people who are affected by lupus globally. In the meantime, there have bee few attempts to summarize lupus data from sub-Saharan africa. We therefore conducted a systematic review and meta-analysis addressing systemic lupus erythematosus in Native sub-Saharan Africans. This paper both serves as repository for and describes the data obtained by qualitative and quantitative synthesis, notably the pooled prevalence of autoantibodies, the pooled frequency of cumulative drug use, the prevalence of comorbidities/complications and the mortality rate in Native sub-Saharan Africans with systemic lupus erythematosus. These data are interpreted in the research article titled "Systemic lupus erythematosus in Native sub-Saharan Africans: a systematic review and meta-analysis" (Essouma et al., 2019) [1].

Genetic analysis for rs2280205 (A>G) and rs2276961 (T>C) in SLC2A9 polymorphism for the susceptibility of gout in Cameroonians: a pilot study.

OBJECTIVE: To determine the association of non-synonymous variants rs2280205 and rs2276961 of the SLC2A9 gene to gout in Cameroonians. RESULTS: In a case-control study including 30 patients with acute gout matched to 30 healthy volunteers. We searched for polymorphism of the targeted variants using Restriction Fragment Length Polymorphism following polymerize chain reaction. Fisher exact test and Student t-test were used to compare variables, with a threshold of significance set at 0.05. The mean age of participants was 58 ± 8 years with 28 (93%) males. The family history of gout was found in one-third of the cases (p > 0.05). Uricemia was higher in cases than controls (p < 0.001) but 24 h urate excretion was similar in both groups (p > 0.05). Ancestral alleles (G and C) and their homozygous genotypes (GG and CC) of the targeted variants were predominant in both groups (p < 0.001). The polymorphisms of targeted variants were not associated with gout, and do not influence uric acid concentration in blood and urine. Non-synonymous variants rs2280205 and rs2276961 are not associated with gout in Cameroonians. However, the hereditary component of the disease suggests the influence of other genetic and/or environmental factors.

Ophthalmic Manifestations in Chronic Inflammatory Rheumatic Diseases at a Referral Hospital of Yaounde, Cameroon.

PURPOSE: To determine the profile of ophthalmic manifestations in chronic inflammatory rheumatic diseases (CIRD). METHODS: Observational study at the Yaounde Central Hospital and Innel Medical Centre (2004 to 2012). RESULTS: The study population (n = 36) consisted of 14 men and 22 women with average age of 47.9 ± 17.2 years. Cases of CIRD were rheumatoid arthritis (n = 16), systemic lupus erythematosus (n = 8), ankylosing spondylitis (n = 8), mixed connective tissue disease (n = 2), scleroderma (n = 1), and juvenile idiopathic arthritis (n = 1). Ophthalmic manifestations found in 22 (61.1%) patients were dry eye syndrome (n = 7), cataract (n = 6), anterior uveitis (n = 6), glaucoma (n = 4), and suspected maculopathy (n = 1). No association was found between steroids used and supcapsular cataract (p = 0.06) or glaucoma (p = 0.06). CONCLUSION: Ocular manifestations occurred in 61.1% of CIRD. Dry eye syndrome and anterior uveitis were commonly observed.

Rheumatoid polyarthritis suspected in an HIV patient with scleritis, peripheral ulcerative keratitis, and anterior uveitis.

INTRODUCTION: Scleritis and peripheral ulcerative keratitis are ocular manifestations found in many inflammations and infections. Therefore, their association should prompt a search for inflammatory or infectious causes that may be life-threatening, especially in the context of AIDS due to HIV infection. FINDINGS: We report the case of a 37-year-old female, first seen in 2011 with a nodular scleritis in the right eye and a peripheral ulcerative keratitis, a necrotizing scleritis, and a granulomatous anterior uveitis in the left eye, in the context of chronic polyarthropathies that had evolved over 6 months. The patient was diagnosed with AIDS (HIV) in 2008 and was on antiretroviral therapy for the past 2 years. Ophthalmic workup was negative for opportunistic infections and potential causes of scleritis and peripheral ulcerative keratitis, and the patient was unresponsive to topical antibacterial and anti-inflammatory treatment. Ocular lesion resolution and articular swelling improvement was observed less than 6 weeks after sulfasalazine treatment. Based on American College of Rheumatology/European League Against Rheumatism classification criteria, and considering the good response to the treatment (sulfasalazine), diagnosis of rheumatoid arthritis was made in the absence of confirmatory lab tests results. CONCLUSION: In the context of ocular manifestations associated with polyarthropathies, coexisting pathologies should be considered. Diagnostic workup of chronic inflammatory rheumatism should be carried out, even in the context of HIV/AIDS.

In Black Africans with rheumatoid arthritis, ACPA recognize citrullinated fibrinogen and the derived peptides α36-50Cit38,42 and ß60-74Cit60,72,74, like in Caucasians.

Well documented in Caucasians and Asians, the diagnostic value of anti-CCP2 antibodies has been confirmed in Black African populations. However, autoantibodies to other citrullinated peptides/proteins and their fine specificities have not yet been studied. Here, we show that in Cameroonian patients, anti-citrullinated fibrinogen autoantibodies (AhFibA) are sensitive (73%) diagnostic markers for RA. We also determine that autoantibodies directed to α36-50Cit38,42 or ß60-74Cit60,72,74 peptides which bear the immunodominant epitopes of citrullinated fibrin, are present in similar proportions in Black Africans and Caucasians with 25/56 (45%) and 41/56 (73%) positive RA-sera in Cameroonians, respectively. They also account for almost all the AhFibA reactivities since 38/41 (93%) AhFibA-positive sera contain anti-α36-50Cit38,42 and/or anti-ß60-74Cit60,72,74 autoantibodies. Finally, HLA-DRB1 SE alleles were associated with higher titres of AhFibA and anti-ß60-74Cit60,72,74 autoantibodies. In the genetic and environmental backgrounds of Black Africans, AhFibA are a hallmark of RA like in Caucasians, moreover they recognize the same fibrin epitopes.

[Synovial Osteochondromatosis At The Rheumatology Unit Of The Yaounde Central Hospital]. / Osteochondromatose Synoviale En Rhumatologie A L'Hopital Central De Yaounde, Cameroun.

Synovial osteochondromatosis is a disease characterized by a benign metaplastic cartilaginous proliferation. There are very few studies on synovial osteochondromatosis in Sub Saharan Africa. We report on 10 observations.We conducted a retrospective study carried out from January 2004 to December 2008, in Synovial osteochondromatosis patients attending the Rheumatology Unit of the Yaounde Central Hospital. We studied 3 women and 7 men, with an average age of 27 years±13 (range: 14 and 89 years old). The knee was the most affected joint (observed in 9 cases) and the metacarpophalangeal joint of the thumb was affected in 1 case. Pain was constant, and joint motion limitation was observed in 6 cases, swelling of the joint in 4 cases, cracking of the joint in 2 cases and nodules were noted in 1 case. None of these patients presented an inflammatory syndrome. Radiological signs were: calcified chondromas in all 10 cases, associated with degenerative lesions in 3 cases. Every patient received an analgesic and a non-steroidal anti-inflammatory medication. Only 3 patients (patients 1, 4 and 5) underwent surgical synovectomy. None of the patients underwent arthroscopic surgery or synoviorthesis.Synovial osteochondromatosis manifestations in our patients were similar to what has been described in the literature, only differing in that surgical care was not constant.

L'ostéochondromatose synoviale est une maladie, qui se caractérise par une prolifération métaplasique bénigne cartilagineuse. Elle est peu décrite en Afrique Sub Saharienne. Nous rapportons dix observations.Il s'agissait d'une étude rétrospective sur dossier des cas d'ostéochondromatose synoviale colligés dans le service de rhumatologie de l'Hôpital Central de Yaoundé de Janvier 2004 à Décembre 2008.Dix observations ont été retenues chez trois femmes et de Sept hommes, dont l'âge moyen était de 27 ans±13, avec les extrêmes de 14 et 89 ans. Le genou était atteint dans 9 cas et l'atteinte de l'articulation métacarpophalangienne a été observée dans un cas. La douleur était constante, le blocage articulaire était noté dans 6 cas, la tuméfaction articulaire dans 4 cas, le craquement articulaire dans 2 cas et la présence de nodules dans un cas. Aucun patient n'avait eu un syndrome inflammatoire. Les signes radiologiques observés étaient les suivants : chondromes calcifiés dans les 10 cas, associés à des lésions dégénératives dans 3 cas. Tous les patients avaient reçu un traitement associant un antalgique et un anti-inflammatoire non stéroïdien. Seuls trois patients avaient eu un traitement chirurgical (patients 1, 4, 5), consistant en une synovectomie totale. Aucun patient de cette série n'avait eu une arthroscopie ni une synoviorthèse.La présentation de l'ostéochondromatose synoviale des patients de cette série était superposable aux données de la littérature, à la seule différence de la prise en charge chirurgicale qui n'était pas constante.

Investigation of Caucasian rheumatoid arthritis susceptibility loci in African patients with the same disease.

INTRODUCTION: The largest genetic risk to develop rheumatoid arthritis (RA) arises from a group of alleles of the HLA DRB1 locus ('shared epitope', SE). Over 30 non-HLA single nucleotide polymorphisms (SNPs) predisposing to disease have been identified in Caucasians, but they have never been investigated in West/Central Africa. We previously reported a lower prevalence of the SE in RA patients in Cameroon compared to European patients and aimed in the present study to investigate the contribution of Caucasian non-HLA RA SNPs to disease susceptibility in Black Africans. METHODS: RA cases and controls from Cameroon were genotyped for Caucasian RA susceptibility SNPs using Sequenom MassArray technology. Genotype data were also available for 5024 UK cases and 4281 UK controls and for 119 Yoruba individuals in Ibadan, Nigeria (YRI, HapMap). A Caucasian aggregate genetic-risk score (GRS) was calculated as the sum of the weighted risk-allele counts. RESULTS: After genotyping quality control procedures were performed, data on 28 Caucasian non-HLA susceptibility SNPs were available in 43 Cameroonian RA cases and 44 controls. The minor allele frequencies (MAF) were tightly correlated between Cameroonian controls and YRI individuals (correlation coefficient 93.8%, p = 1.7E-13), and they were pooled together. There was no correlation between MAF of UK and African controls; 13 markers differed by more than 20%. The MAF for markers at PTPN22, IL2RA, FCGR2A and IL2/IL21 was below 2% in Africans. The GRS showed a strong association with RA in the UK. However, the GRS did not predict RA in Africans (OR = 0.71, 95% CI 0.29 - 1.74, p = 0.456). Random sampling from the UK cohort showed that this difference in association is unlikely to be explained by small sample size or chance, but is statistically significant with p<0.001. CONCLUSIONS: The MAFs of non-HLA Caucasian RA susceptibility SNPs are different between Caucasians and Africans, and several polymorphisms are barely detectable in West/Central Africa. The genetic risk of developing RA conferred by a set of 28 Caucasian susceptibility SNPs is significantly different between the UK and Africa with p<0.001. Taken together, these observations strengthen the hypothesis that the genetic architecture of RA susceptibility is different in different ethnic backgrounds.

Diagnostic value of anti-cyclic citrullinated peptides and association with HLA-DRB1 shared epitope alleles in African rheumatoid arthritis patients.

INTRODUCTION: The purpose of this study was to examine the diagnostic performance of autoantibodies against citrullinated peptides/proteins (ACPA) and to determine the prevalence of HLA-DRB1 shared epitope alleles (SE) in African patients with rheumatoid arthritis (RA). METHODS: Serum levels of anti-cyclic citrullinated peptides antibodies (anti-CCP2, anti-CCP3), IgM and IgA rheumatoid factors (RF) were measured by enzyme-linked immunosorbent assay in the serum of 56 consecutive RA patients regularly followed in the Rheumatology Unit of the School of Medicine, University of Yaoundé, Yaoundé, Cameroon. Genotyping of HLA-DRB1 alleles was performed by polymerase chain reaction and hybridization with sequence-specific oligonucleotide probes on microbeads arrays. Fifty-one patients with other inflammatory rheumatic diseases and 50 healthy individuals were included as controls. RESULTS: An anti-CCP2 assay showed the best diagnosis sensitivity (82%) and specificity (98%) with high positive predictive (PPV) (96%) and negative predictive values (NPV) (91%). Thirty percent of RA patients were carrying at least one copy of the HLA-DRB1 shared epitope (SE) compared to 10% and 14% of patients with other inflammatory rheumatic diseases and healthy individuals, respectively. The presence of the SE was associated with the production of ACPA. CONCLUSIONS: Anti-CCP2 antibodies are useful markers of RA in African patients. In this cohort, the prevalence of the SE is higher in RA patients than in controls but lower than that reported in patient cohorts of European ancestry. The discrepancy between the high prevalence of ACPA-positive patients and the relatively low number of SE-positive cases suggest that, in addition to SE, other genetic factors control the development of ACPA in African RA patients.