A genome-wide association study for rheumatoid arthritis replicates previous HLA and non-HLA associations in a cohort from South Africa.

The complex pathogenesis of rheumatoid arthritis (RA) is not fully understood, with few studies exploring the genomic contribution to RA in patients from Africa. We report a genome-wide association study (GWAS) of South-Eastern Bantu-Speaking South Africans (SEBSSAs) with seropositive RA (n = 531) and population controls (n = 2653). Association testing was performed using PLINK (logistic regression assuming an additive model) with sex, age, smoking and the first three principal components as covariates. The strong association with the Human Leukocyte Antigen (HLA) region, indexed by rs602457 (near HLA-DRB1), was replicated. An additional independent signal in the HLA region represented by the lead SNP rs2523593 (near the HLA-B gene; Conditional P-value = 6.4 × 10-10) was detected. Although none of the non-HLA signals reached genome-wide significance (P < 5 × 10-8), 17 genomic regions showed suggestive association (P < 5 × 10-6). The GWAS replicated two known non-HLA associations with MMEL1 (rs2843401) and ANKRD55 (rs7731626) at a threshold of P < 5 × 10-3 providing, for the first time, evidence for replication of non-HLA signals for RA in sub-Saharan African populations. Meta-analysis with summary statistics from an African-American cohort (CLEAR study) replicated three additional non-HLA signals (rs11571302, rs2558210 and rs2422345 around KRT18P39-NPM1P33, CTLA4-ICOS and AL645568.1, respectively). Analysis based on genomic regions (200 kb windows) further replicated previously reported non-HLA signals around PADI4, CD28 and LIMK1. Although allele frequencies were overall strongly correlated between the SEBSSA and the CLEAR cohort, we observed some differences in effect size estimates for associated loci. The study highlights the need for conducting larger association studies across diverse African populations to inform precision medicine-based approaches for RA in Africa.

The impact of COVID-19 on rheumatology practice across Africa.

OBJECTIVES: To identify the changes in rheumatology service delivery across the five regions of Africa from the impact of the COVID-19 pandemic. METHODS: The COVID-19 African Rheumatology Study Group created an online survey consisting of 40 questions relating to the current practices and experiences of rheumatologists across Africa. The CHERRIES checklist for reporting results of internet e-surveys was adhered to. RESULTS: A total of 554 completed responses were received from 20 countries, which include six in Northern Africa, six in West Africa, four in Southern Africa, three in East Africa and one in Central Africa. Consultant grade rheumatologists constituted 436 (78.7%) of respondents with a mean of 14.5 ± 10.3 years of experience. A total of 77 (13.9%) rheumatologists avoided starting a new biologic. Face-to-face clinics with the use of some personal protective equipment continued to be held in only 293 (52.9%) rheumatologists' practices. Teleconsultation modalities found usage as follows: telephone in 335 (60.5%), WhatsApp in 241 (43.5%), emails in 90 (16.3%) and video calls in 53 (9.6%). Physical examinations were mostly reduced in 295 (53.3%) or done with personal protective equipment in 128 (23.1%) practices. Only 316 (57.0%) reported that the national rheumatology society in their country had produced any recommendation around COVID-19 while only 73 (13.2%) confirmed the availability of a national rheumatology COVID-19 registry in their country. CONCLUSION: COVID-19 has shifted daily rheumatology practices across Africa to more virtual consultations and regional disparities are more apparent in the availability of local protocols and registries.

Laser speckle contrast analysis is a reliable measure of digital blood perfusion in Black Africans with systemic sclerosis.

OBJECTIVES: Laser speckle contrast analysis (LASCA) is evolving as a promising non-invasive tool to assess cutaneous microvascular function in systemic sclerosis (SSc). Reliability studies have mainly focused on Caucasian populations. To determine for the first time the inter-rater reliability of fingertip blood perfusion (BP) using LASCA in Black South African patients with SSc. METHODS: Consecutive Black adult patients with SSc were evaluated for peripheral BP using LASCA. Mean BP in defined regions of interest for dorsal fingertips and volar fingertips were measured in two subgroups of 20 SSc patients, each by three independent operators. Two operators were experienced in the use of the LASCA instrument and one was newly trained. Standardised protocols for conditions were followed for all measurements. Inter-rater reliability was tested using the intraclass correlation coefficient (ICC). RESULTS: The majority (87.5%) of the 40 patients included were females and 67.5% had diffuse cutaneous SSc. The mean age (standard deviation) was 48.5 (9.9) years and the median disease duration (interquartile range) was 8.5 (4, 13) years. There was good to excellent agreement, inter-rater ICC (dorsal fingertip range: 0.86-0.97 and volar fingertip range: 0.85-0.96), in both subgroups irrespective of operator skill. CONCLUSIONS: LASCA is a credible instrument in patients of Black ethnicity with SSc, and across operator experience.

Racial differences in systemic sclerosis disease presentation: a European Scleroderma Trials and Research group study.

OBJECTIVES: Racial factors play a significant role in SSc. We evaluated differences in SSc presentations between white patients (WP), Asian patients (AP) and black patients (BP) and analysed the effects of geographical locations. METHODS: SSc characteristics of patients from the EUSTAR cohort were cross-sectionally compared across racial groups using survival and multiple logistic regression analyses. RESULTS: The study included 9162 WP, 341 AP and 181 BP. AP developed the first non-RP feature faster than WP but slower than BP. AP were less frequently anti-centromere (ACA; odds ratio (OR) = 0.4, P < 0.001) and more frequently anti-topoisomerase-I autoantibodies (ATA) positive (OR = 1.2, P = 0.068), while BP were less likely to be ACA and ATA positive than were WP [OR(ACA) = 0.3, P < 0.001; OR(ATA) = 0.5, P = 0.020]. AP had less often (OR = 0.7, P = 0.06) and BP more often (OR = 2.7, P < 0.001) diffuse skin involvement than had WP. AP and BP were more likely to have pulmonary hypertension [OR(AP) = 2.6, P < 0.001; OR(BP) = 2.7, P = 0.03 vs WP] and a reduced forced vital capacity [OR(AP) = 2.5, P < 0.001; OR(BP) = 2.4, P < 0.004] than were WP. AP more often had an impaired diffusing capacity of the lung than had BP and WP [OR(AP vs BP) = 1.9, P = 0.038; OR(AP vs WP) = 2.4, P < 0.001]. After RP onset, AP and BP had a higher hazard to die than had WP [hazard ratio (HR) (AP) = 1.6, P = 0.011; HR(BP) = 2.1, P < 0.001]. CONCLUSION: Compared with WP, and mostly independent of geographical location, AP have a faster and earlier disease onset with high prevalences of ATA, pulmonary hypertension and forced vital capacity impairment and higher mortality. BP had the fastest disease onset, a high prevalence of diffuse skin involvement and nominally the highest mortality.

Pregnancy and Takayasu arteritis: case-based review.

Takayasu arteritis (TA) is a rare large vessel vasculitis that particularly affects women of child-bearing age. Management of pregnant patients with TA is often challenging due to the cardiovascular and cerebrovascular complications of the disease. We report two new cases of pregnancy in patients with TA and review all published cases from sub-Saharan Africa. Analysis of 16 pregnancies in 15 patients (including our two cases) showed that seven patients had radiographic Type V TA disease, namely involvement of the entire length of the aorta. Four patients were newly diagnosed with TA during pregnancy and two pregnancies were unbooked at time of first presentation. Seven pregnancies were complicated by disease flares (n = 4) and/or hypertension (n = 6). Four pregnancies resulted in preterm delivery and six required caesarean sections. There was one documented case of pre-eclampsia resulting in the only maternal death. Intrauterine growth restriction was documented in two of six pregnancies in which foetal ultrasonography was performed. There were four low birth weight infants and one fresh stillbirth (associated with the maternal death). In the handful of case reports of pregnancy in TA from sub-Saharan Africa, both maternal and foetal outcomes were generally good and similar to international findings. In a substantial proportion of patients, the diagnosis of TA was made in pregnancy, reflecting challenges of access to appropriate health care in resource constrained sub-Saharan Africa.

Autoantibody status is not associated with early treatment response to first-line methotrexate in patients with early rheumatoid arthritis.

Objectives: In RA, the relationship between autoantibody status and treatment response to MTX remains unclear. We investigated the association between autoantibody status and early remission in newly diagnosed RA patients treated with MTX using real-world data. Methods: RA-patients initially treated with MTX were selected from an international observational database (METEOR). Patients were stratified into autoantibody-positive (RF- and/or ACPA-positive) or autoantibody negative (RF- and ACPA-negative). The effect of autoantibody status on the chance of achieving remission within 3 to 6 months was analysed using Cox-proportional hazards regression. Results: Data from 1826 RA patients were available for analysis. DAS remission was achieved in 17% (318/1826). This was similar in autoantibody-positive [17% (282/1629)] and -negative patients [18% (36/197)]. Hence, autoantibody positivity was not associated with remission [hazard ratio (HR) 0.89, 95% CI 0.57, 1.38]. Similar findings were found when stratified for MTX monotherapy (HR 0.75, 95% CI 0.41, 1.37) or combination treatment (HR 0.76, 95% CI 0.37, 1.54). Good physical function (HAQ < 0.5) was achieved in 33% (530/1590) of all patients. Autoantibody-positivity was also not associated with HAQ < 0.5 (HR 1.05, 95% CI 0.71, 1.57). Conclusion: Autoantibody status is not associated with early remission in newly diagnosed RA-patients receiving MTX. This indicates that MTX is effective as an initial treatment strategy regardless of autoantibody status.

Relationship of Visceral Fat and Adipokines with Cardiometabolic Diseases in Psoriasis.

As part of a larger cross-sectional, case-control study on cardiometabolic diseases in psoriasis this study investigated the association of visceral fat and serum adipokines with psoriasis and cardiometabolic diseases. A total of 103 patients with psoriasis and 98 controls, matched for body mass index, ethnicity and sex, were recruited over 15 months. Abdominal visceral fat was measured by computerized tomo-graphy. Logistic regression analysis revealed that visceral fat was associated with psoriasis (odds ratio (95% confidence interval): 1.56 (1.15, 2.11)), hyper-triglyceridaemia (1.67 (1.22, 2.28)), low high-density lipoprotein (1.63 (1.19, 2.22)) and type 2 diabetes (1.77 (1.24, 2.54)), (p < 0.005 for all). These respective associations were linked to serum interleukin-6, adiponectin, tumour necrosis factor and insulin resistance. Psoriasis was associated with type 2 diabetes (7.94 (2.64, 23.9)), independent of visceral fat. These data suggest that visceral fat and its mediators play a key role in psoriasis-associated cardiometabolic diseases. Psoriasis itself is associated with an increased risk of type 2 diabetes.

Tobacco-Derived Lipopolysaccharide, Not Microbial Translocation, as a Potential Contributor to the Pathogenesis of Rheumatoid Arthritis.

Microbial lipopolysaccharides (LPS) have been implicated in the pathogenesis of rheumatoid arthritis (RA), possibly driving a systemic inflammatory response that may trigger the development and/or exacerbation of the disease. To explore the existence of this mechanism in African RA patients, we have measured systemic levels of LPS and its surrogate, LPS-binding protein (LBP), as well as those of intestinal fatty acid-binding protein (I-FABP), pulmonary surfactant protein D (SP-D), and cotinine in serum to identify possible origins of LPS, as well as associations of these biomarkers with rheumatoid factor (RF) and anticitrullinated peptide (aCCP) autoantibodies and the DAS 28-3 clinical disease severity score. A cohort of 40 disease-modifying antirheumatic drug-naïve, black South African RA patients rated by compound disease scores and 20 healthy subjects and 10 patients with chronic obstructive pulmonary disease (COPD) as controls were included in this study. Levels of the various biomarkers and autoantibodies were measured using a combination of ELISA and immunofluorimetric and immunoturbidometric procedures. LPS levels were lowest in the RA group compared to the healthy controls (p = 0.026) and COPD patients (p = 0.017), while LBP levels were also significantly lower in RA compared to the healthy individuals (p = 0.036). Levels of I-FABP and SP-D were comparable between all three groups. Categorisation of RA patients according to tobacco usage revealed the following significant positive correlations: LBP with C-reactive protein (p = 0.0137); a trend (p = 0.073) towards an association of LBP with the DAS 28-3 disease severity score; RF-IgG antibodies with both LPS and LBP (p = 0.033 and p = 0.041, respectively); aCCP-IgG antibodies with LPS (p = 0.044); and aCCP-IgG with RF-IgM autoantibodies (p = 0.0016). The findings of this study, several of them novel, imply that tobacco products, as opposed to microbial translocation, represent a potential source of LPS in this study cohort of RA patients, again underscoring the risks posed by tobacco usage for the development and severity of RA.

Light intensity physical activity increases and sedentary behavior decreases following total knee arthroplasty in patients with osteoarthritis.

PURPOSE: To describe objectively measured changes in the volume and pattern of physical activity and sedentary behavior in patients undergoing total knee arthroplasty for osteoarthritis. METHODS: Physical activity and sedentary behavior were measured in patients (13 males, 76 females) with a mean age of 64 years (range 55-80) and end-stage osteoarthritis of the knee, using an accelerometer (ActiGraph GT3X+) for seven consecutive days (24 h/day) prior to, 6 weeks and 6 months after total knee arthroplasty. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), University of California Los Angeles (UCLA) Activity index and range of motion (ROM) were also assessed. RESULTS: Proportion of time spent in sedentary behavior decreased from baseline to 6 months (mean 70.1 vs. 64.0%; p = 0.009) and the interruptions to sedentary behavior improved between baseline and 6 months after total knee arthroplasty (mean 85.0-93.0 breaks/day, p = 0.014). Proportion of time spent in light physical activity increased from baseline to 6 months after total knee arthroplasty (29.0 vs. 34.8%; p = 0.008). There was no change in time spent in moderate to vigorous physical activity after total knee arthroplasty. WOMAC (median 71.0 vs. 4.0, p < 0.001), UCLA (median 2.0 vs. 5.0, p < 0.001) as well as ROM [median (0.0°-90.0°) vs. (0.0°-110°), p < 0.05] scores improved between baseline and 6 months after total knee arthroplasty. CONCLUSION: Clinically, functional improvements in patients following total knee arthroplasty may be assessed by objectively measuring changes in low intensity activity behaviors. The use of accelerometers in this study gives new insights into activity accumulation patterns in a clinical population and highlights their use in determining a behavioral response to an intervention. LEVEL OF EVIDENCE: II.

Gender differences in early systemic sclerosis patients: a report from the EULAR scleroderma trials and research group (EUSTAR) database.

OBJECTIVES: To describe differences in clinical presentation between men and women in a large group of patients with early (<3 years' duration) systemic sclerosis (SSc) according to disease subsets. METHODS: A cross-sectional analysis of the prospective EULAR Scleroderma Trial and Research database (EUSTAR) was performed. Patients fulfilling preliminary ACR 1980 classification criteria for SSc, with less than 3 years from the first non-Raynaud's symptom at first entry, were selected. A group of patients with less than 3 years from the first SSc symptom, including Raynaud's phenomenon, was also analysed. SSc related variables, including antibodies, SSc subsets, disease activity and organ involvement were included. Descriptive and bivariate analyses were performed. RESULTS: A total of 1,027 patients were included, 90% Caucasian, 80% women, and 40% with diffuse cutaneous disease. In early stages of SSc, men showed more frequently than women active disease, diffuse cutaneous subset, anti-Scl-70 antibodies, elevated acute phase reactants, muscular and pulmonary involvement. Differences between men and women were confirmed in the limited, but not in the diffuse SSc subset. The results were similar when 650 patients with less than three years from the first SSc symptom, including Raynaud's phenomenon, were analysed. CONCLUSIONS: In early stages of SSc, men present signs and symptoms of more severe disease. In the limited disease subset, men might appear with clinical features and organ involvement similar to those of the diffuse subgroup. In clinical practice, the identification of such differences might help to select the appropriate management for each particular patient.

Interstitial lung disease in South Africans with systemic sclerosis.

To investigate the frequency, severity and predictors of interstitial lung disease (ILD) in a cohort of South Africans with systemic sclerosis (SSc). Retrospective record review of SSc patients attending a tertiary Connective Tissue Diseases Clinic. Patients with ILD, defined by a combination of clinical findings, imaging, and lung function tests were compared to patients without ILD in terms of demographics, clinical features and autoantibodies. The majority (86.8%) of the 151 patients included were of Black ethnicity, 40% had ILD, of whom 39% had moderate-severe lung disease. Univariate predictors of ILD included: disease duration (OR 1.08, 95% CI 1.01-1.15); cough (OR 2.93, 95% CI 1.37-6.29); dyspnoea (OR 2.44, 95% CI 1.23-4.87); bibasal crackles (OR 7.58, 95% CI 3.31-17.37); diffuse cutaneous SSc (dcSSc) (OR 4.55, 95% CI 2.10-9.86) and a speckled anti-nuclear antibody (ANA) pattern (OR 2.47, 95% CI 1.25-4.90). Conversely, limited cutaneous disease (OR 0.22, 95% CI 0.09-0.50) and anti-centromere antibody (ACA) (OR 0.12, 95% CI 0.02-0.97) were protective. Independent predictors of ILD on multivariate analysis were bibasal crackles (OR 9.43, 95% CI 3.25-27.39), disease duration (OR 1.19, 95% CI 1.09-1.30) and speckled ANA (OR 2.95, 95% CI 1.22-7.15). Almost all (86.4%) patients received immunosuppressive treatment and the leading cause of death was related to ILD itself (44.4%). In this cohort of predominantly Black South Africans, SSc ILD was common and carried a poor prognosis. ILD occurred mainly, but not exclusively, in patients with dcSSc, especially those with a speckled ANA pattern. Conversely, the presence of ACA was protective against ILD.

Comparison of the diagnostic potential of three anti-citrullinated protein antibodies as adjuncts to rheumatoid factor and CCP in a cohort of South African rheumatoid arthritis patients.

PURPOSE: A retrospective comparison of the prevalence and diagnostic value of anti-Sa, anti-CEP-1, and anti-MCV autoantibodies relative to those of the established autoantibodies, composite RF and anti-CCP-IgG used routinely for RA diagnosis as a component of the ACR 2010 criteria, in a cohort of disease-modifying anti-rheumatic drug naïve African RA patients (n = 75). METHODS: Serum concentrations of anti-Sa, anti-CEP-1 and anti-MCV autoantibodies were measured using ELISA procedures, while anti-CCP-IgG antibodies were determined by fluorescence enzyme immunoassay, and composite RF by latex-enhanced laser nephelometry. RESULTS: The seropositivity frequencies of anti-Sa, anti-CEP-1 and anti-MCV antibodies for the RA patients were 82, 72, 85%, respectively, while that of anti-CCP-IgG and RF was 87% for both. Overall, anti-MCV demonstrated the best specificity, positive predictive value (PPV), odds ratio and positive likelihood ratio of all the types of autoantibody tested. CONCLUSION: These observations in this unique cohort of RA patients indicated novel associations of all three autoantibodies in regard to HLA-SE risk alleles, disease severity and tobacco use that were not reported before. Elevated anti-Sa titers designated a propensity of higher disease and high-risk alleles in our cohort. Anti-CEP-1 association with HLA-SE homozygosity and high-risk alleles is also novel in this group. Of note, measurement of anti-MCV antibodies on presentation, either as an adjunctive or even as a stand-alone test, surpassed all other biomarkers investigated here and, therefore, may add value to clinical management.

Mapping and predicting mortality from systemic sclerosis.

OBJECTIVES: To determine the causes of death and risk factors in systemic sclerosis (SSc). METHODS: Between 2000 and 2011, we examined the death certificates of all French patients with SSc to determine causes of death. Then we examined causes of death and developed a score associated with all-cause mortality from the international European Scleroderma Trials and Research (EUSTAR) database. Candidate prognostic factors were tested by Cox proportional hazards regression model by single variable analysis, followed by a multiple variable model stratified by centres. The bootstrapping technique was used for internal validation. RESULTS: We identified 2719 French certificates of deaths related to SSc, mainly from cardiac (31%) and respiratory (18%) causes, and an increase in SSc-specific mortality over time. Over a median follow-up of 2.3 years, 1072 (9.6%) of 11 193 patients from the EUSTAR sample died, from cardiac disease in 27% and respiratory causes in 17%. By multiple variable analysis, a risk score was developed, which accurately predicted the 3-year mortality, with an area under the curve of 0.82. The 3-year survival of patients in the upper quartile was 53%, in contrast with 98% in the first quartile. CONCLUSION: Combining two complementary and detailed databases enabled the collection of an unprecedented 3700 deaths, revealing the major contribution of the cardiopulmonary system to SSc mortality. We also developed a robust score to risk-stratify these patients and estimate their 3-year survival. With the emergence of new therapies, these important observations should help caregivers plan and refine the monitoring and management to prolong these patients' survival.

Clinical determinants of elevated systolic pulmonary artery pressure measured by transthoracic Doppler echocardiography in early systemic sclerosis.

OBJECTIVES: To explore the prevalence and clinical associations of elevated systolic pulmonary artery pressure (sPAP), measured by Transthoracic Doppler-echocardiography (TTE) in patients with early systemic sclerosis (SSc). METHODS: A cross-sectional analysis of the prospective EULAR Scleroderma Trial and Research (EUSTAR) database was performed. SSc patients with <3 years from the first non-Raynaud's phenomenon (RP) symptom at baseline EUSTAR visit, were selected. Elevated sPAP was defined as sPAP>40 mmHg on baseline TTE. First visit SSc related variables, including disease subsets, antibodies and visceral involvement, were examined. RESULTS: From 1,188 patients, 81% were women. Mean (SD) age at first non-RP symptom was 50 (14) years, 55% had limited cutaneous SSc (lcSSc) and 42% active disease. Elevated sPAP was found in 17% of patients, both lcSSc and diffuse cutaneous SSc (dcSSc). In lcSSc, older age at first non-RP symptom, ACA positivity, joint contractures, restrictive defect and lower DLCO, were independently associated with elevated sPAP. In dcSSc, older age at first non-RP symptom, longer time between RP onset and first non-RP symptom, digital ulcers, cardiac blocks, and proteinuria were associated with elevated sPAP. CONCLUSIONS: The prevalence of elevated sPAP on TTE in early SSc patients is considerable. Association with cardiac, lung and renal involvement suggests that, although some patients might have pulmonary arterial hypertension, others may present pulmonary hypertension secondary to lung or heart involvement. Our findings emphasize the need to consider right heart catheterisation in selected early SSc patients with PH suspicion, to clearly determine the cause of PH.

Incidence and predictors of cutaneous manifestations during the early course of systemic sclerosis: a 10-year longitudinal study from the EUSTAR database.

OBJECTIVES: To longitudinally map the onset and identify risk factors for skin sclerosis and digital ulcers (DUs) in patients with systemic sclerosis (SSc) from an early time point after the onset of Raynaud's phenomenon (RP) in the European Scleroderma Trials and Research (EUSTAR) cohort. METHODS: 695 patients with SSc with a baseline visit within 1 year after RP onset were followed in the prospective multinational EUSTAR database. During the 10-year observation period, cumulative probabilities of cutaneous lesions were assessed with the Kaplan-Meier method. Cox proportional hazards regression analysis was used to evaluate risk factors. RESULTS: The median modified Rodnan skin score (mRSS) peaked 1 year after RP onset, and was 15 points. The 1-year probability to develop an mRSS ≥2 in at least one area of the arms and legs was 69% and 25%, respectively. Twenty-five per cent of patients developed diffuse cutaneous involvement in the first year after RP onset. This probability increased to 36% during the subsequent 2 years. Only 6% of patients developed diffuse cutaneous SSc thereafter. The probability to develop DUs increased to a maximum of 70% at the end of the 10-year observation. The main factors associated with diffuse cutaneous SSc were the presence of anti-RNA polymerase III autoantibodies, followed by antitopoisomerase autoantibodies and male sex. The main factor associated with incident DUs was the presence of antitopoisomerase autoantibodies. CONCLUSION: Early after RP onset, cutaneous manifestations exhibit rapid kinetics in SSc. This should be accounted for in clinical trials aiming to prevent skin worsening.

Smoking and Air Pollution as Pro-Inflammatory Triggers for the Development of Rheumatoid Arthritis.

INTRODUCTION: Smoking is now well recognized not only as a risk factor for rheumatoid arthritis (RA), but also as a determinant of disease activity, severity, response to therapy, and possibly mortality. METHODS: Studies, mostly recent, which have provided significant insights into the molecular and cellular mechanisms which underpin the pathogenesis of smoking-related RA, as well as the possible involvement of other types of outdoor and indoor pollution form the basis of this review. RESULTS: Smoking initiates chronic inflammatory events in the lungs. These, in turn, promote the release of the enzymes, peptidylarginine deiminases 2 and 4 from smoke-activated, resident and infiltrating pulmonary phagocytes. Peptidylarginine deiminases mediate conversion of various endogenous proteins to putative citrullinated autoantigens. In genetically susceptible individuals, these autoantigens trigger the production of anti-citrullinated peptide, pathogenic autoantibodies, an event which precedes the development of RA. CONCLUSIONS: An increasing body of evidence has linked chronic inflammatory events in the lungs of smokers, to the production of anti-citrullinated peptide autoantibodies and development of RA. Creation of awareness of the associated risks, assessment of smoking status and implementation of compelling antismoking strategies must be included in the routine clinical management of patients presenting with suspected RA. IMPLICATIONS: Chronic inflammatory mechanisms operative in the lungs of smokers lead to the production of anti-citrullinated protein antibodies which, in turn, drive the development of RA. These mechanistic insights not only reinforce the association between smoking and risk for RA, but also the necessity to increase the level of awareness in those at highest risk.

Pitfalls in the assessment of smoking status detected in a cohort of South African RA patients.

This study was conceived in an attempt to explain the unexpectedly high frequency of elevated levels of serum cotinine measured retrospectively in a cohort of predominantly black South African females with rheumatoid arthritis (RA), findings that were inconsistent with the smoking histories derived from health questionnaires. The discrepant findings suggested either a greater tendency towards underreporting of smoking status in the study cohort, or possible confounding effects of the use of smokeless tobacco products. In addition to the cohort of RA patients (n = 138, of whom 115 (83 %) were female), blood samples were also taken from a second cohort consisting of 29 declared smokers, 18 (62 %) of whom where females, 29 smokeless tobacco (SLT) users (all female), and 22 non-users of any tobacco products, 18 (82 %) of whom were females. Serum cotinine levels were determined using an ELISA procedure. Cotinine levels of >10.0 ng/ml were detected in serum specimens from 43 (31 %), RA patients of whom 35 (81 %) were female, with a median value of 50.1 ng/ml and interquartile range (iqr) of 68.6. Only 18 of the 35 females indicated that they smoked. The groups of declared smokers and SLT users had equivalent median serum cotinine levels of 88.0 ng/ml (iqr = 10.8 ng/ml) and 87.0 ng/ml (iqr = 15.6 ng/ml), respectively, while cotinine was undetectable in specimens from non-tobacco product users (<0.2 ng/ml). Users of SLT products in South Africa are predominantly female and have serum cotinine levels which are comparable with those of current smokers, raising concerns about the validity of measurement of cotinine as the sole objective marker of smoking status in populations with high usage of SLTs. This situation can be rectified by ensuring that usage of SLT products is accurately recorded in health questionnaires, while inclusion of measurement of one or more additional, objective biomarkers of smoking in combination with cotinine may enable reliable distinction between smoking and usage of SLTs which, given the associated risks, is a strategy of particular relevance in RA.

Rationale, design and protocol of a longitudinal study assessing the effect of total knee arthroplasty on habitual physical activity and sedentary behavior in adults with osteoarthritis.

BACKGROUND: Physical activity levels are decreased and sedentary behaviour levels are increased in patients with knee osteoarthritis (OA). However, previous studies have shown that following total knee arthroplasty (TKA), objectively measured physical activity levels do not change compared to before the surgery. Very few studies have objectively assessed sedentary behaviour following TKA. This study aims to assess patterns of objective habitual physical activity and sedentary behaviour in patients with knee OA and to determine whether these change following TKA. METHODS: Patients diagnosed with knee osteoarthritis and scheduled for unilateral primary total knee arthroplasty will be recruited from the Orthopaedic Division at the Charlotte Maxeke Johannesburg Academic Hospital. Eligible participants will have assessments completed one week before the scheduled arthroplasty, six weeks, and six months post-operatively. The primary outcomes are habitual physical activity and sedentary behaviour which will be measured using accelerometry (Actigraph GTX3+ and activPal monitors) at the specific time points. The secondary outcomes will be improvements in osteoarthritis-specific quality of life measures using the following questionnaires: Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee injury and Osteoarthritis Outcome Score (KOOS), Oxford Knee Score (OKS), Knee Society Clinical Rating System (KSS), UCLA activity index; subjective pain scores, and self reported sleep quality. DISCUSSION: The present study will contribute to the field of musculoskeletal health by providing a rich detailed description of the patterns of accumulation of physical activity and sedentary behaviour in patients with knee OA. These data will contribute to existing knowledge using an objective measurement for the assessment of functional ability after total knee arthroplasty. Although studies have used accelerometry to measure physical activity in knee OA patients, the data provided thus far have not delved into the detailed patterns of how and when physical activity is accumulated before and after TKA. Accurate assessment of physical activity is important for physical activity interventions that target special populations. TRIAL REGISTRATION: NCT02675062 (4 February 2016).

Tight control of rheumatoid arthritis in a resource-constrained setting: a randomized controlled study comparing the clinical disease activity index and simplified disease activity index.

OBJECTIVE: The aim of this study was to explore the clinical utility of the clinical disease activity index (CDAI). We compared the disease control with protocolized treatment adjustment following a tight control strategy utilizing either the simplified disease activity index (SDAI) or the CDAI. METHODS: In a prospective 12 month study, DMARD-naive RA patients were randomized to either a CDAI or SDAI arm and were treated with traditional DMARDs, increased on a monthly basis according to a predefined protocol to achieve low disease activity. RESULTS: Of 102 patients (84 females, 96 Black Africans), the mean symptom duration was 3.0 years (s.d. 3.8) and the mean 28-joint DAS (DAS28) at baseline was 6.2 (s.d. 1.2). By 12 months, the proportion of patients in the CDAI and SDAI groups achieving low disease activity (30% and 32%) and remission (33 and 34%) were similar. There were no significant differences in the mean DAS28 or its components or in HAQ Disability Index or health-related quality of life scores. Baseline predictors of low disease activity at 12 months were shorter symptom duration (P = 0.03) and lower HAQ-DI score (P = 0.04). CONCLUSION: Given that the CDAI performed as well as the SDAI, and considering the cost savings and convenience because no acute phase reactant test is necessary, we suggest the CDAI may be an appropriate tool for monthly disease activity monitoring as part of a tight control strategy in developing countries.