Autoantibodies in black South Africans with systemic lupus erythematosus: spectrum and clinical associations

Clinical and laboratory profiles of systemic lupus erythematosus patients in a new rheumatology clinic in southwestern Nigeria

Introduction

The aims were to study the sociodemographic characteristics of patients presenting to the clinic and to study the clinical and serological pattern of systemic lupus erythematosus (SLE) in a new rheumatology clinic of a predominantly Yoruba population.

Material and methods

This was a retrospective, cross-sectional study conducted over 7 years (January 2017 - December 2023). Patients who satisfied the 1997 American College of Rheumatology (ACR) and/or the 2012 Systemic Lupus International Collaborating Clinics (SLICC) classification criteria were enrolled using their medical records. Patients with overlap syndromes and other inflammatory or noninflammatory rheumatic diseases were excluded from the study. Their sociodemographic, clinical, laboratory, and treatment data were retrieved from their medical records and analysed using IBM SPSS version 23.0 software.

Results

A total of 65 patients were diagnosed with SLE with a frequency of 15.8%. The mean age ±SD of the patients at presentation was 33.85 years ±11.01 and the female to male ratio was 9.8 : 1. The median (IQR) duration of symptoms at presentation was 7.0 months (3-24). The common clinical presentations included synovitis (86.2%), acute cutaneous rash (53.8%), oral ulcers (52.3%), nonscarring alopecia (50.8%), and serositis (47.7%). Proteinuria was seen in 37.7% of the patients and the predominant renal histopathological feature was Class IV. Antinuclear antibody was 100% positive with 50.94% of the patients having a titre of 1 : 5,120 and above. Anti-double-stranded deoxyribonucleic acid and anti-Smith antibodies each had 50% prevalence. Dyslipidaemia was found in 76.7% of the patients.

Conclusions

The study's findings are largely consistent with similar studies done in Africa. Further prospective multi-centred studies are needed to further determine the epidemiological characteristics of the disease in Nigeria with a multi-ethnic population.

Cardiac Abnormalities in Relation to the Disease Activity Index Among Systemic Lupus Erythematosus Patients in a Tertiary Hospital: A Cross-Sectional Study

BACKGROUND

 Systemic lupus erythematosus (SLE) is a multisystem autoimmune connective tissue disorder involving multiple organs and systems. Cardiovascular involvement in SLE patients is a major cause of morbidity and mortality. Although subclinical cardiac abnormalities exist among SLE patients, they are rarely screened for. Echocardiography has been demonstrated to be a useful tool for the early diagnosis of cardiac abnormalities in SLE patients, many of which are clinically silent. Early recognition of cardiovascular abnormalities is vital for the prompt initiation of the appropriate management. This study aims to determine the prevalence of various structural and functional cardiac abnormalities among SLE patients and to determine its association with the modified SLE Disease Activity Index 2000 (modified SLEDAI-2K).

METHODS

 The study was a cross-sectional study of SLE patients at the Korle-Bu Teaching Hospital (KBTH), Accra, Ghana, from June to December 2021. The setting was the rheumatology outpatient clinic of the KBTH and included adult men and women, 18 years and above, diagnosed with SLE with no known cardiac abnormalities. The baseline demographic and clinical characteristics of the participants were determined. A detailed transthoracic echocardiogram was performed for all patients. The frequency of common cardiac pathologies was determined and compared between those with a high modified SLEDAI-2K and those with a low modified SLEDAI-2K.

RESULTS

 Ninety-nine SLE patients participated in the study with a mean age of 35.12 years. Females formed the majority (90.9%) of the participants. The mean age at diagnosis of SLE was 28.7 years and the mean disease duration was 4.6 years. All of the participants were on at least two disease-modifying medications. The mean modified SLEDAI-2K score was 9.1. Thirty-five percent (35%) of the patients had mild to moderately active disease and 39% had severely active disease. Sixty-six (66%) out of the severely active disease group had abnormal echocardiographic findings, while 28% of those with mild to moderate disease had abnormal echocardiographic findings. Echocardiographic abnormalities were found in 56 patients (47%), out of which 8.7% had valvular involvement, 15.7% had diastolic dysfunction, 5.2% had left ventricular hypertrophy (LVH), and 0.9% had left ventricular systolic dysfunction (LVSD). About 12% of the participants had pulmonary hypertension and 1% had pericardial involvement. The odds of echocardiographic abnormalities were 13.7 times higher in SLE patients with high disease activity compared to those with low disease activity (odds ratio (OR) = 13.714, 95% confidence interval (CI) = 3.804-49.442, p < 0.001). There was no significant association between cardiac abnormalities and SLE duration. No significant correlation between cardiac abnormalities and modified SLEDAI-2K score was found.  Conclusion: Cardiac abnormalities, especially left ventricular diastolic dysfunction (LVDD), valvular involvement, and pulmonary hypertension, are common in SLE patients. For SLE patients, especially those with active diseases, echocardiographic assessment should be considered in the management of SLE patients to enable early detection of cardiac abnormalities, early treatment, and thus a decrease in morbidity and mortality associated with cardiovascular involvement in SLE patients.

Assessing outcomes in a lupus nephritis cohort over a 40-year period

OBJECTIVES

To characterize a LN cohort over 40 years, assessing its evolution, analysing two major outcomes: the development of end-stage renal disease and mortality rates in the first 5 years after LN diagnosis.

METHODS

An observational retrospective study of patients with LN, followed up from 1975 at University College Hospital. Patients were divided into four groups, depending on the decade of LN diagnosis: 1975-1985 (D1), 1986-1995 (D2), 1996-2005 (D3) and 2006-2015 (D4). Comparison between groups was performed with respect to demographic, clinical, serological and histological characteristics and outcome.

RESULTS

Two hundred and nineteen patients with LN were studied. There was a change in ethnic distribution, with a decreasing proportion of Caucasians (58.6% in D1 to 31.3% in D4, P = 0.018) and increase in African-ancestry (17.2% in D1 to 39.6% in D4, P = 0.040). Serological and histological patterns changed throughout time, with a reduction in class IV nephritis (51.7% in D1 to 27.1% in D4, P = 0.035), and increase in class II nephritis (10% in D2 to 18.8% in D4, P = 0.01) and anti-extractable nuclear antigen antibody positivity (17.2% in D1 to 83.3% in D4, P = 0.0001). The 5-year mortality rates decreased from D1 (24.1%) to D2 (4%), stabilizing for the next 30 years. The 5-year progression to end-stage renal disease remained stable over the decades.

CONCLUSION

Despite the changes in treatment of LN in the past 20 years, we have reached a plateau in 5-year mortality and progression to end-stage renal disease rates, suggesting that new therapeutic and management approaches, and strategies to enhance adherence, are needed to improve outcomes further in LN patients.

Health Disparities in Rheumatic Diseases: Understanding Global Challenges in Africa, Europe, Latin America, and Asia and Proposing Strategies for Improvement

Rheumatic diseases reach across continents with some similarities as well as unique challenges. The intersection between genetic factors, environmental exposures and socioeconomic factors, as well as challenges, with delays in access to subspecialty care and medications, manifest in different ways. By understanding both the challenges and successes in different countries, while also recognizing the significant diversity both within and across continents, unified strategies to improve rheumatic disease outcomes and decrease disparities among the most vulnerable groups can be developed and disseminated.

Patient ancestry significantly contributes to molecular heterogeneity of systemic lupus erythematosus

Gene expression signatures can stratify patients with heterogeneous diseases, such as systemic lupus erythematosus (SLE), yet understanding the contributions of ancestral background to this heterogeneity is not well understood. We hypothesized that ancestry would significantly influence gene expression signatures and measured 34 gene modules in 1566 SLE patients of African ancestry (AA), European ancestry (EA), or Native American ancestry (NAA). Healthy subject ancestry-specific gene expression provided the transcriptomic background upon which the SLE patient signatures were built. Although standard therapy affected every gene signature and significantly increased myeloid cell signatures, logistic regression analysis determined that ancestral background significantly changed 23 of 34 gene signatures. Additionally, the strongest association to gene expression changes was found with autoantibodies, and this also had etiology in ancestry: the AA predisposition to have both RNP and dsDNA autoantibodies compared with EA predisposition to have only anti-dsDNA. A machine learning approach was used to determine a gene signature characteristic to distinguish AA SLE and was most influenced by genes characteristic of the perturbed B cell axis in AA SLE patients.

Transcriptional profiling of lupus patients and healthy controls reveals ancestry-related differences and transcriptional heterogeneity among lupus patients.

The immunologic etiology of psychiatric manifestations in systemic lupus erythematosus: A narrative review on the role of the blood brain barrier, antibodies, cytokines and chemokines

INTRODUCTION

The aim of this narrative review is to provide an overview of the literature on the possible immunologic pathophysiology of psychiatric manifestations of neuropsychiatric systemic lupus erythematosus (NPSLE).

METHODS

A systematic search on PubMed was conducted. English studies with full text availability that investigated the correlation between blood-brain barrier (BBB) dysfunction, intrathecal synthesis of antibodies, antibodies, cytokines, chemokines, metalloproteinases, complement and psychiatric NPSLE manifestations in adults were included.

RESULTS

Both transient BBB-dysfunction with consequent access of antibodies to the cerebrospinal fluid (CSF) and intrathecal synthesis of antibodies could occur in psychiatric NPSLE. Anti-phospholipid antibodies, anti-NMDA antibodies and anti-ribosomal protein p antibodies seem to mediate concentration dependent neuronal dysfunction. Interferon-α may induce microglial engulfment of neurons, direct neuronal damage and production of cytokines and chemokines in psychiatric NPSLE. Several cytokines, chemokines and matrix metalloproteinase-9 may contribute to the pathophysiology of psychiatric NPSLE by attracting and activating Th1-cells and B-cells.

DISCUSSION

This potential pathophysiology may help understand NPSLE and may have implications for the diagnostic management and therapy of psychiatric NPSLE. However, the presented pathophysiological model is based on correlations between potential immunologic etiologies and psychiatric NPSLE that remain questionable. More research on this topic is necessary to further elucidate the pathophysiology of NPSLE.

Anti-Smith antibody is associated with disease activity in patients with new-onset systemic lupus erythematosus

Although anti-Smith (Sm) antibody is a highly specific antibody for systemic lupus erythematosus (SLE), the significance of anti-Sm antibody in patients with SLE is unclear. This study aimed to evaluate the association between anti-Sm antibodies and disease activity in patients with new-onset SLE. We included patients who were tested for anti-Sm antibodies at SLE diagnosis and within 12 months after diagnosis. SLE disease activity index (SLEDAI) was obtained at the time of the anti-Sm antibody test. The baseline disease activity was compared between patients with and without anti-Sm antibodies. The longitudinal association between disease activity and anti-Sm antibodies was also evaluated in total patients and in those with anti-Sm antibodies. Among 92 patients who were tested for anti-Sm antibodies at SLE diagnosis, 67 and another 67 patients were followed up for the presence of anti-Sm antibodies at 6 and 12 months, respectively. Although the baseline SLEDAI was comparable in patients with and without anti-Sm antibodies, the serum level of anti-Sm antibody was significantly correlated with SLEDAI (P = 0.003). At 12 months, anti-Sm antibody positivity was associated with higher SLEDAI and anti-dsDNA titer (P = 0.002, both). In addition, the changes in anti-Sm antibody titer over 12 months were correlated with the alterations in SLEDAI (P = 0.029).Anti-Sm antibody was associated with the baseline disease activity and the alteration of disease activity in patients with new-onset SLE. Monitoring of anti-Sm antibody titer may help assess the disease activity in SLE.

Evidence of a distinct group of Black African patients with systemic lupus erythematosus

Background

The autoimmune disease systemic lupus erythematosus (SLE) occurs more frequently in patients of African descent with high morbidity and mortality. Current SLE diagnostic criteria including antinuclear antibody (ANA) reactivity are derived largely from non-African populations. This study characterises ANA reactivity patterns and relates them to SLE clinical presentation in Black African patients.

Methods

Sera from Black participants (61 patients with SLE and 100 controls) aged 1-81 years were analysed for reactivity against the antigens: uridine 1-ribonuclear protein, Smith uridine-1-5 ribonuclear protein antigen, soluble substance-A, recombinant Ro-52, soluble substance-B, Scl-70, cytoplasmic histidyl-tRNA synthetase antigen, proliferating cell nuclear antigen (PCNA), nucleosomes, ribonuclear P-protein, antimitochondrial antibody M2 (AMA-M2), histones, double-stranded DNA (dsDNA), centromere protein B and polymyositis-sclerosis overlap antigen.

Findings

A significantly higher proportion (97%) of the 61 patients with SLE had detectable autoantibody reactivity compared with 15% of the 100 controls (p<0.001). The highest frequencies of autoantibody reactivity in patients with SLE were against the dsDNA antigen (41%) and PCNA (54%). Anti-PCNA and anti-dsDNA reactivity were mutually exclusive (p<0.001) giving rise to two distinct groups of Black African patients with SLE. The first group (n=25) had reactivity profiles consistent with international standard SLE definitions, including anti-dsDNA reactivity, and was 13 times more likely to present with joint symptoms. The larger, second group (n=34), characterised by anti-PCNA and anti-AMA-M2 reactivity, was nine times more likely to present with only cutaneous symptoms.

Interpretation

Our study demonstrates a need to extend autoantibody panels to include anti-PCNA in the diagnostic process of Black African patients and further refine the predictive values of the reactivity to different antigens to differentiate SLE syndromes in African populations.

Clinical and immunological pattern and outcome of Egyptian systemic lupus erythematosus patients: a single center experience

Objective

The objective of this study was to describe the clinical and immunological pattern and disease outcome in Egyptian systemic lupus erythematosus patients.

Patients and methods

The medical records of 770 systemic lupus erythematosus patients who were followed from 2002–2015 at Kasr Alainy Hospital, Cairo University, were retrospectively reviewed.

Results

There were 707 (91.8%) females. The mean age at disease onset was 22.1 ± 8.6 and the disease duration was 6.1 ± 4.5 years. The main clinical manifestations were mucocutaneous (90.8% with oral ulcers affecting 52.5%), arthritis (80.3%), nephritis (67.8%), hematologic involvement (64.9%), serositis (55.2%) and neuropsychiatric manifestations (44.3%). The frequencies of antinuclear antibodies were 94.3%, anti-dsDNA 74.8%, anti-Smith 11%, anticardiolipin antibodies 29.5% and lupus anticoagulant 19.8%. Infections, predominantly bacterial, affected 337 (43.8%) patients. Thirty-three (4.3%) patients died. The main causes of death were sepsis and disease activity. The five- and 10-year survival rates for the total cohort were 97.4% and 96.3%, respectively, and were 96% and 92%, respectively for those with nephritis ( p = 0.008). Autoimmune hemolytic anemia, thrombocytopenia, elevated serum creatinine, a higher damage index, infections, a higher glucocorticoid dose and cyclophosphamide use ≥ six months were associated with an increased risk of mortality with odds ratios of 3.69, p < 0.01; 4.12, p < 0.001; 1.54, p < 0.001; 1.43, p < 0.001; 5.08, p < 0.001; 5.04, p < 0.001 and 2.25, p = 0.03, respectively.

Conclusion

Compared to other cohorts, a relatively lower mean age at systemic lupus erythematosus onset and higher frequencies of oral ulcers, serositis and nephritis were found.

Autoantibodies Associated With Connective Tissue Diseases: What Meaning for Clinicians?

Connective tissue diseases (CTDs) such as systemic lupus erythematosus, systemic sclerosis, myositis, Sjögren's syndrome, and rheumatoid arthritis are systemic diseases which are often associated with a challenge in diagnosis. Autoantibodies (AAbs) can be detected in these diseases and help clinicians in their diagnosis. Actually, pathophysiology of these diseases is associated with the presence of antinuclear antibodies. In the last decades, many new antibodies were discovered, but their implication in pathogenesis of CTDs remains unclear. Furthermore, the classification of these AAbs is nowadays misused, as their targets can be localized outside of the nuclear compartment. Interestingly, in most cases, each antibody is associated with a specific phenotype in CTDs and therefore help in better defining either the disease subtypes or diseases activity and outcome. Because of recent progresses in their detection and in the comprehension of their pathogenesis implication in CTD-associated antibodies, clinicians should pay attention to the presence of these different AAbs to improve patient's management. In this review, we propose to focus on the different phenotypes and features associated with each autoantibody used in clinical practice in those CTDs.

The effect of ethnicity and genetic ancestry on the epidemiology, clinical features and outcome of systemic lupus erythematosus

In this in-depth review, we examine the worldwide epidemiology of SLE and summarize current knowledge on the influence of race/ethnicity on clinical manifestations, disease activity, damage accumulation and outcome in SLE. Susceptibility to SLE has a strong genetic component, and trans-ancestral genetic studies have revealed a substantial commonality of shared genetic risk variants across different genetic ancestries that predispose to the development of SLE. The highest increased risk of developing SLE is observed in black individuals (incidence 5- to 9-fold increased, prevalence 2- to 3-fold increased), with an increased risk also observed in South Asians, East Asians and other non-white groups, compared with white individuals. Black, East Asian, South Asian and Hispanic individuals with SLE tend to develop more severe disease with a greater number of manifestations and accumulate damage from lupus more rapidly. Increased genetic risk burden in these populations, associated with increased autoantibody reactivity in non-white individuals with SLE, may explain the more severe lupus phenotype. Even after taking into account socio-economic factors, race/ethnicity remains a key determinant of poor outcome, such as end-stage renal failure and mortality, in SLE. Community measures to expedite diagnosis through increased awareness in at-risk racial/ethnic populations and ethnically personalized treatment algorithms may help in future to improve long-term outcomes in SLE.

Clinical features and outcome of lupus myocarditis in the Western Cape, South Africa

BACKGROUND

African American ethnicity is independently associated with lupus myocarditis compared with other ethnic groups. In the mixed racial population of the Western Cape, South Africa, no data exists on the clinical features/outcome of lupus myocarditis.

OBJECTIVES

The objective of this study was to give a comprehensive description of the clinical features and outcome of acute lupus myocarditis in a mixed racial population.

METHODS

Clinical records (between 2008 and 2014) of adult systemic lupus erythematosus (SLE) patients at a tertiary referral centre were retrospectively screened for a clinical and echocardiographic diagnosis of lupus myocarditis. Clinical features, laboratory results, management and outcome were described. Echocardiographic images stored in a digital archive were reanalysed including global and regional left ventricular function. A poor outcome was defined as lupus myocarditis related mortality or final left ventricular ejection fraction (LVEF) <40%.

RESULTS

Twenty-eight of 457 lupus patients (6.1%) met inclusion criteria: 92.9% were female and 89.3% were of mixed racial origin. Fifty-three per cent of patients presented within three months after being diagnosed with SLE. Seventy-five per cent had severely active disease (SLE disease activity index ≥ 12) and 67.9% of patients had concomitant lupus nephritis. Laboratory results included: lymphopenia (69%) and an increased aRNP (61.5%). Treatment included corticosteroids (96%) and cyclophosphamide (75%); 14% of patients required additional immunosuppression including rituximab. Diastolic dysfunction and regional wall motion abnormalities occurred in > 90% of patients. LVEF improved from 35% to 47% (p = 0.023) and wall motion score from 1.88 to 1.5 (p = 0.017) following treatment. Overall mortality was high (12/28): five patients (17.9%) died due to lupus myocarditis (bimodal pattern). Patients who died of lupus myocarditis had a longer duration of SLE (p = 0.045) and a lower absolute lymphocyte count (p = 0.041) at diagnosis. LVEF at diagnosis was lower in patients who died of lupus myocarditis (p = 0.099) and in those with a persistent LVEF < 40% (n = 5; p = 0.046).

CONCLUSIONS

This is the largest reported series on lupus myocarditis. The mixed racial population had a similar prevalence, but higher mortality compared with other ethnic groups (internationally published literature). Patients typically presented with high SLE disease activity and the majority had concomitant lupus nephritis. Lymphopenia and low LVEF at presentation were of prognostic significance, associated with lupus myocarditis related mortality or a persistent LVEF < 40%.

A study of the influence of ethnicity on serology and clinical features in lupus

OBJECTIVE

The objective of this study was to review the links between ethnicity, serology and clinical expression in systemic lupus erythematosus (SLE) in a single cohort that was followed over a 36-year period.

PATIENTS AND METHODS

Patients with SLE treated at the University College London Hospitals (UCLHs) between January 1978 and December 2013 formed the cohort. We assessed the demographic, clinical and serological data. Standard methods were used for laboratory testing. The Student t test and Mann-Whitney U test were used for the continuous variables; the Fisher's exact test was used for the categorical variables.

RESULTS

We studied 624 SLE patients: There were 571 women (91.5%), with a mean age at diagnosis of 29.0 ± 6.5 years; and 53 men (8.5%), with a mean age at diagnosis of 29.4 ± 15.3 years. Ethnically, 369 of the patients were European, 100 were Afro-Caribbean, 77 were East Asian, 56 were South Asian and 21 were of mixed ethnicity. The East Asian patients developed the disease at a younger age than the other ethnic groups (p < 0.0001). The Afro-Caribbean patients were less frequently associated with the presence of rash and photosensitivity, and the non-European patients were more likely to have alopecia and renal involvement. The South Asian patients were significantly associated with musculoskeletal and neurological involvement, serositis, Sicca syndrome and hematological features. The Afro-Caribbean patients had the highest prevalence of anti-Smith, anti-RNP, anti-Ro and anti-La antibodies. Anti-IgG anticardiolipin (aCL) antibodies were significantly associated with the non-East Asian groups; and hypocomplementemia was common in the East Asians. Rash, alopecia, mouth ulcers, serositis, neurological, joint and renal involvement were significantly associated with the presence of anti-Smith and anti-RNP antibodies in the Afro-Caribbean group. We also observed an association of joint involvement and the presence of anti-Ro and anti-La antibodies in this group.

CONCLUSIONS

The East Asian patients developed their SLE disease at a younger age than the other ethnic groups. Cutaneous involvement was more frequent in those who were not Afro-Caribbean. Serositis, joint and neurological involvement were more frequently diagnosed in the South Asian patients. Anti-ENA antibodies were frequently associated with the Afro-Caribbean patients.

Clinical associations of anti-Smith antibodies in PROFILE: a multi-ethnic lupus cohort

The aim of this study was to determine the association of anti-Sm antibodies with clinical manifestations, comorbidities, and disease damage in a large multi-ethnic SLE cohort. SLE patients (per American College of Rheumatology criteria), age ≥16 years, disease duration ≤10 years at enrollment, and defined ethnicity (African American, Hispanic or Caucasian), from a longitudinal US cohort were studied. Socioeconomic-demographic features, cumulative clinical manifestations, comorbidities, and disease damage (as per the Systemic Lupus International Collaborating Clinics Damage Index [SDI]) were determined. The association of anti-Sm antibodies with clinical features was examined using multivariable logistic regression analyses adjusting for age, gender, ethnicity, disease duration, level of education, health insurance, and smoking. A total of 2322 SLE patients were studied. The mean (standard deviation, SD) age at diagnosis was 34.4 (12.8) years and the mean (SD) disease duration was 9.0 (7.9) years; 2127 (91.6%) were women. Anti-Sm antibodies were present in 579 (24.9%) patients. In the multivariable analysis, anti-Sm antibodies were significantly associated with serositis, renal involvement, psychosis, vasculitis, Raynaud's phenomenon, hemolytic anemia, leukopenia, lymphopenia, and arterial hypertension. No significant association was found for damage accrual. In this cohort of SLE patients, anti-Sm antibodies were associated with several clinical features including serious manifestations such as renal, neurologic, and hematologic disorders as well as vasculitis.

TULUP (TUnisian LUPus): a multicentric study of systemic lupus erythematosus in Tunisia

AIM

Clinical features of systemic lupus erythematosus (SLE) have been described from different geographical regions around the world. However, data from North African countries, including Tunisia, are scarce.

METHODS

The aim of this retrospective multicenter study was to analyze demographic, clinical, laboratory features and outcome of SLE in Tunisia throughout 14 Departments of Internal Medicine and to compare them with those of other ethnic and geographic groups.

RESULTS

Seven hundred and forty-nine cases of SLE were recorded (American College of Rheumatology criteria) during a 17-year period (1989-2006). They were 676 women and 73 men with an average age at SLE onset of approximately 30.66 years. Our Tunisian patients were characterized by a high frequency of photosensitivity (67.6%), malar rash (68.7%), renal involvement (49.5%) and anti-Sm antibodies (44.8%). Infections were the main complications. Fifty-six (7.5%) patients died during the study period.

CONCLUSION

Potential limitations and biases in our study need discussion. Specific recruitment of patients in tertiary referral centers may be the source of selection bias and adding to the frequency of moderate or even severe diseases. The therapeutic management and outcome monitoring were heterogeneous due to the fact that patients were evaluated by different doctors. However, this study remains the most representative of Tunisian SLE patients recruited from all parts of Tunisia.

Lupus in Africa: can we dispel the myths and face the challenges?

The epidemiology of systemic lupus erythematosus (SLE) in Africa is largely undetermined, and the perception persists that the incidence of SLE on the continent is very low. Recent studies as well as our own experience, however, suggest that this is not the case. We have conducted a survey amongst medical practitioners in Africa to determine their experiences of diagnosing and treating SLE patients, and the results suggest that significant numbers of African patients are presenting with SLE. The apparent low incidence rate in Africa may be the result of underdiagnosis due to poor access to health care, low disease recognition within primary health care settings, limited access to diagnostic tools and inadequate numbers of specialist physicians. Treatment of SLE in Africa is also restricted by availability and affordability of immunosuppressive drugs. We have established the African Lupus Genetics Network (ALUGEN), an informal network of clinicians and researchers in Africa who have an interest in SLE, in order to facilitate combined clinical and research efforts towards improved outcomes for African SLE patients.

Association of systemic lupus erythematosus clinical features with European population genetic substructure

Systemic Lupus Erythematosus (SLE) is an autoimmune disease with a very varied spectrum of clinical manifestations that could be partly determined by genetic factors. We aimed to determine the relationship between prevalence of 11 clinical features and age of disease onset with European population genetic substructure. Data from 1413 patients of European ancestry recruited in nine countries was tested for association with genotypes of top ancestry informative markers. This analysis was done with logistic regression between phenotypes and genotypes or principal components extracted from them. We used a genetic additive model and adjusted for gender and disease duration. Three clinical features showed association with ancestry informative markers: autoantibody production defined as immunologic disorder (P = 6.8×10(-4)), oral ulcers (P = 6.9×10(-4)) and photosensitivity (P = 0.002). Immunologic disorder was associated with genotypes more common in Southern European ancestries, whereas the opposite trend was observed for photosensitivity. Oral ulcers were specifically more common in patients of Spanish and Portuguese self-reported ancestry. These results should be taken into account in future research and suggest new hypotheses and possible underlying mechanisms to be investigated. A first hypothesis linking photosensitivity with variation in skin pigmentation is suggested.

HIV and systemic lupus erythematosus: the clinical and diagnostic dilemmas of having dual diagnosis

We present the case of a young black African woman living in the UK who presented with systemic lupus erythematosus (SLE) and HIV. The reported coexistence of HIV and SLE is unusual with fewer than 30 published cases. We discuss some of the clinical and diagnostic challenges that face clinicians when a patient presents with both conditions. In particular, we discuss the overlap in symptoms, signs and laboratory findings, and the difficulties that this may pose in terms of making a diagnosis. The implications that having a dual diagnosis may have for treating each condition are also discussed. With increased HIV testing in a variety of clinical settings there is likely to be an increase in detection of similar cases. This case emphasizes the need for careful diagnostic testing and judicious interpretation of the validity of laboratory results in order to reach an accurate diagnosis in such patients.

Digital vasculitis in systemic lupus erythematosus: a minor manifestation of disease activity?

The objective of this study is to determine if digital vasculitis (DV), a clinical manifestation with a high systemic lupus erythematosus disease activity index (SLEDAI) score, is associated with lupus severity. DV and other clinical manifestations defined according to the SLEDAI were evaluated in 168 consecutive patients with systemic lupus erythematosus (SLE). Two groups were defined according to presence (DV+, n = 27) or absence of DV (DV-, n = 141) at the time of evaluation. The exclusion criterion was the presence of antiphospholipid syndrome (Sapporo's criteria). The two groups were comparable with regard to age (P = 0.09), gender (P = 1.00), white race (P = 0.81), and disease duration (P = 0.78). Compared to the DV- group, the DV+ group had a significantly higher frequency of mucocutaneous manifestations (66.7 vs. 39.0%, P = 0.01), haematological abnormalities (22.2 vs. 6.4%, P = 0.02) and constitutional symptoms (11.1 vs. 0.7%, P = 0.01). Renal and neurological involvements were similar in both groups (P = 0.57 and P = 1.00, respectively). The evaluation of each SLEDAI parameter confirmed that the DV+ group had higher frequencies of mild manifestations, such as new rash (P = 0.02), alopecia (P = 0.02), oral ulcers (P = 0.045), fever (P = 0.01) and leucopenia (P = 0.005). In contrast, both groups had similarly increased anti-dsDNA (P = 0.78) and decreased complement levels (P = 0.29). In conclusion, DV in patients with SLE identifies a subgroup of a mild disease. The high 'weighted' index attributed to this alteration in the SLEDAI score should therefore be revised.

Prevalence and clinical correlates of anti‐phospholipid antibodies in South Africans with systemic lupus erythematosus

OBJECTIVE

To determine the prevalence and clinical correlates of anti-phospholipid antibodies (aPL), including anti-cardiolipin antibodies (aCL), lupus anti-coagulant (LA), anti-beta2-glycoprotein 1 (abeta2GP1), and anti-prothrombin (aPT) antibodies, in Black South African patients with systemic lupus erythematosus (SLE).

METHODS

A cross-sectional study of 100 SLE patients in whom clinical characteristics, including features of the anti-phospholipid syndrome (APS), disease activity, and damage were documented, and sera tested for aCL, abeta2GP, and aPT of all isotypes, and LA.

RESULTS

Positive aCL, abeta2GPI, aPT, and LA were found in 53, 84, 20, and 2 patients, respectively. Immunoglobulin (Ig)A aCL and IgG abeta2GPI were the commonest aCL (49.1%) and abeta2GPI (47%) isotypes, respectively. IgA abeta2GPI were associated with both a history of thrombosis alone (p<0.05) and a history of any clinical feature, thrombosis, and/or spontaneous abortion of the APS (p<0.05); IgA aCL were associated with a history of any clinical APS event (p<0.05); and abeta2GPI of any isotype were associated with a history of arthritis (p<0.001).

CONCLUSION

Our findings provide further evidence that screening for abeta2GPI and IgA aCL isotypes may improve the risk assessment for APS in SLE patients of African extraction. Further prospective studies are warranted to determine the clinical utility of these tests and to elucidate the genetic basis for the increased IgA aPL response in SLE patients of African extraction.

Pattern of systemic lupus erythematosus among Nigerians

Systemic lupus erythematosus (SLE) has rarely being reported among African Blacks, in contrast with African-Americans. Such reports have been mostly case reports. Our encounter with new cases shows that this disease may not be rare after all. The objective of this study was to study the clinical presentations, laboratory and serological characteristics of Nigerians presenting with SLE. This is part of a retrospective study of patients presenting with rheumatic complaints to a private practice rheumatology clinic, Arthrimed Specialist Clinic located in Lagos, Nigeria. This is a retrospective study of consecutive SLE patients seen in a rheumatology clinic over a 6-year period and diagnosed using the ACR Criteria for SLE. Laboratory tests and serology were carried out when possible. Treatment was initiated with immunosuppressives, steroids, anti epileptics, aspirin and anti hypertensives as indicated. SLE accounted for 5.28% of all the 1,250 rheumatology cases seen over the study period of 6 years. Female constituted 95.5% of the 66 cases seen. The subjects were aged 17-55 with a mean of 33 years at presentation and had the symptoms for a mean of 2.6 years. Polyarthralgia, fever and hair loss were the most common presentation. Neuropsychiatric presentations were common. Erythrocyte sedimentation rate was markedly elevated in most cases. Anti-nuclear antibody titres were markedly high and were mostly speckled staining pattern. Treatment was with conventional immunosuppressives. SLE may not be uncommon among African blacks, contrary to previous reports. A high index of suspicion is needed for this otherwise severe disease in blacks. Early aggressive treatment with immunosuppressives is indicated.

Clinical and serological correlates of anti-Sm autoantibodies in Chinese patients with systemic lupus erythematosus: 1,584 cases

To investigate the association of anti-Sm antibodies with clinical and serological features in systemic lupus erythematosus. A group of 1,584 patients with SLE was recruited. Clinical and laboratory data were compared between patients with and without anti-Sm antibodies. There were 1,424 females and 160 males, the mean age of the patients was 33.2 +/- 12.3 years, and the mean duration of disease was 32.5 +/- 59.4 months. A total of 469 (29.6%) were anti-Sm antibodies positive. The presence of anti-Sm antibodies was associated with arthritis, renal involvement, malar rash, vasculitis and low serum complement C3. The positive rate of anti-nuclear, anti-dsDNA, anti-La/SSB and anti-U1RNP antibodies were significant higher in anti-Sm positive group when compared with anti-Sm negative group. A trend towards a higher presence of anti-Sm antibodies related to an early disease onset was observed. In conclusion, Anti-Sm antibodies are associated with lupus related clinical and laboratory profiles and correlated significantly with disease activity.

Autoantibodies in pediatric systemic lupus erythematosus: ethnic grouping, cluster analysis, and clinical correlations

OBJECTIVE

(1) To evaluate the spectrum of serum autoantibodies in pediatric-onset systemic lupus erythematosus (pSLE) with a focus on ethnic differences; (2) using cluster analysis, to identify patients with similar autoantibody patterns and to determine their clinical associations.

METHODS

A single-center cohort study of all patients with newly diagnosed pSLE seen over an 8-year period was performed. Ethnicity, clinical, and serological data were prospectively collected from 156/169 patients (92%). The frequencies of 10 selected autoantibodies among ethnic groups were compared. Cluster analysis identified groups of patients with similar autoantibody profiles. Associations of these groups with clinical and laboratory features of pSLE were examined.

RESULTS

Among our 5 ethnic groups, there were differences only in the prevalence of anti-U1RNP and anti-Sm antibodies, which occurred more frequently in non-Caucasian patients (p < 0.0001, p < 0.01, respectively). Cluster analysis revealed 3 autoantibody clusters. Cluster 1 consisted of anti-dsDNA antibodies. Cluster 2 consisted of anti-dsDNA, antichromatin, antiribosomal P, anti-U1RNP, anti-Sm, anti-Ro and anti-La autoantibody. Cluster 3 consisted of anti-dsDNA, anti-RNP, and anti-Sm autoantibody. The highest proportion of Caucasians was in cluster 1 (p < 0.05), which was characterized by a mild disease with infrequent major organ involvement compared to cluster 2, which had the highest frequency of nephritis, renal failure, serositis, and hemolytic anemia, or cluster 3, which was characterized by frequent neuropsychiatric disease and nephritis.

CONCLUSION

We observed ethnic differences in autoantibody profiles in pSLE. Autoantibodies tended to cluster together and these clusters were associated with different clinical courses.

Systemic lupus erythematosus in the Fars Province of Iran

Abstract

Clinical features of systemic lupus erythematosus (SLE) have been described from different geographical regions in the world. However, data from many Middle East countries, including Iran, are scarce. This study aims to demonstrate the demographic, clinical, and laboratory characteristics in Iranian patients with SLE. In this prospective study, all the patients referring to Shiraz educational hospitals (Nemazi–Hafez) with SLE (American College of Rheumatology criteria) during a 5-year period (2001 to 2006) were included. A complete history was taken; physical examination and routine hematological, serological, and immunological tests were done for each patient. There were 356 women and 54 men with an average age of 30.27 years at the onset of disease. Of the patients, 78% had hematological abnormalities, 65.5% had articular involvement, 54.5% had photosensitivity, and 60.5% had malar rash. Serositis occurred in 38% of patients of whom 12% had pericarditis and 26% had pleuritis. Nephritis was diagnosed in 48% of the cases and consisted always of glomerular nephritis. Biopsy-proven lupus nephritis was in most cases class IV(49.7% of all the biopsies). Oral ulcers were observed in 28% of patients. Neuropsychiatric manifestations, gastrointestinal involvement, and lymphadenopathy were observed in 31.5%, 8.3%, and 14.2% of patients, respectively. In all, 93% of patients were positive for antinuclear antibodies, whereas antidouble-stranded DNA was positive in 83% of patients. Coomb’s positive hemolytic anemia appeared in 12.4% of the cases. Rheumatoid factor was detected in 9.7% of patients, and lupus erythematosus cell was seen in 32.5% of them. In all, 196 (47.8%) patients represented hypocomplementemia. Regarding hematological manifestations, 74.5% had microcytic hypochromic anemia, 64.6% had leukopenia, and 44.6% had thrombocytopenia; 18 (4.4%) patients died during the study period of which eight (2%) died because of cardiopulmonary involvement. Generally, there was more cutaneous, serositis, and neuropsychiatric involvement in our population than other Middle East countries. Serositis was associated with poorer prognosis, and the pattern of disease in these patients was much more sever than patients without serositis ( P = 0.001). This is the first study of its kind in Iran. More multicenter studies should be undertaken in Iran to describe the pattern of SLE.

Ethnic and geographical differences in systemic lupus erythematosus: an overview

Systemic lupus erythematosus (SLE) is one of the most heterogeneous autoimmune disorders known. There is production of a variety of autoantibodies and patients present with a wide range of symptoms due to multiple organ involvement by the disease process. The underlying cause is not fully understood but it may involve genetic and environmental factors. It is interesting to note that while SLE is found worldwide, it is more commonly found in some countries, and within a country certain ethnic groups appear to be more susceptible to develop this condition than others. Additionally, the presentation and course of SLE appear highly variable between patients of different ethnic origins. For example, African-Americans and Orientals are believed to have a more severe disease than Caucasian whites. But are these ethnic and geographical differences real? If yes, they may provide investigators insight into the underlying pathoaetiology of this condition and pave the way to future research directions in lupus.

Clinical and serological correlates of antinucleosome antibodies in South Africans with systemic lupus erythematosus

Antinucleosome antibodies (AnuA) are increasingly recognized as an important biomarker in the diagnosis and subset stratification of patients with systemic lupus erythematosus (SLE). The aim of the study was to determine the sensitivity, specificity, and clinico-serological correlates of AnuA in black South Africans with SLE. We performed a cross-sectional study of 86 SLE patients attending a tertiary center and 87 control subjects. AnuA were tested using a second-generation enzyme-linked immunosorbent assay (ELISA). The sensitivity, specificity, positive predictive value, and negative predictive value of AnuA were 45.3, 94.3, 88.6, and 63.6%, respectively. The presence of AnuA were strongly associated with the co-presence of anti-dsDNA antibodies (OR = 3.4, p < 0.0005) and antihistone antibodies (OR = 15.7, p < 0.00001). Patients who were seropositive for AnuA were more likely to have skin involvement (discoid lupus and/or malar rash) and had higher SLE disease activity index (SLEDAI) scores and Systemic Lupus International Collaborative Clinics/American College of Rheumatology (SLICC/ACR) damage scores (p < 0.05). IgG anticardiolipin antibody (aCL) levels showed a significant correlation with AnuA ratios (p < 0.01). Our findings provide further evidence that AnuA are a sensitive and specific diagnostic biomarker in SLE. Moreover, our finding that the presence of AnuA, but not anti-dsDNA antibodies, are associated with worse SLICC/ACR damage scores suggest that AnuA may have a role in predicting disease outcome. The correlation between IgG aCL and AnuA is a novel finding that merits further studies to determine possible common peptide specificities of the antibodies.

Functional disability and health-related quality of life in South Africans with rheumatoid arthritis and systemic lupus erythematosus

There is a paucity of data on the impact of chronic rheumatic diseases on functional disability and overall health-related quality of life (HRQOL) in Africans.

MATERIALS AND METHODS

We compared Black South Africans (BSA) with rheumatoid arthritis (RA) (n=50) and systemic lupus erythematosus (SLE) (n=50) to geographically and ethnically matched controls cared for at a tertiary care facility. The modified health assessment questionnaire (mHAQ) and Medical Outcome Study short-form 36 (SF-36) scores and indices of disease activity and organ damage were collected from each group.

RESULTS

Compared to the controls, both the RA and SLE groups fared significantly worse in respect of all the domains and summary scales of the SF-36. Compared to the SLE group, the RA group scored significantly worse with respect to the mHAQ disability index (mHAQ-DI), physical function and bodily pain (BP) SF-36 subscales, and SF-36 summary physical component score (SF-PCS). In the RA group, both the mHAQ-DI and SF-PCS correlated strongly (p<0.005) with the tender joint count, patient global assessment, 28-joint composite disease activity score, physician global assessment, and pain score. The SF-PCS showed only a weak inverse correlation with the swollen joint count (r=-0.29, p<0.05). In the SLE group, the systemic lupus erythematosus disease activity index correlated inversely best with the SF-36 general health subscale (r=-0.56, p<0.0001) and, to a lesser extent, with the mental health, BP, and vitality subscales, and SF-PCS and SF-mental component summary scores.

CONCLUSION

Both RA and SLE have profound effects on HRQOL in BSA, with BP and physical disability particularly worse in RA patients. Disease activity, rather than organ damage or sociodemographic characteristics, correlates best with certain aspects of functional disability and HRQOL in both RA and SLE. Further longitudinal studies are needed to assess the clinical utility of measures of functional disability and HRQOL in this population.

Is antibody clustering predictive of clinical subsets and damage in systemic lupus erythematosus?

OBJECTIVE

To examine autoantibody clusters and their associations with clinical features and organ damage accrual in patients with systemic lupus erythematosus (SLE).

METHODS

The study group comprised 1,357 consecutive patients with SLE who were recruited to participate in a prospective longitudinal cohort study. In the cohort, 92.6% of the patients were women, the mean +/- SD age of the patients was 41.3 +/- 12.7 years, 55.9% were Caucasian, 39.1% were African American, and 5% were Asian. Seven autoantibodies (anti-double-stranded DNA [anti-dsDNA], anti-Sm, anti-Ro, anti-La, anti-RNP, lupus anticoagulant (LAC), and anticardiolipin antibody [aCL]) were selected for cluster analysis using the K-means cluster analysis procedure.

RESULTS

Three distinct autoantibody clusters were identified: cluster 1 (anti-Sm and anti-RNP), cluster 2 (anti-dsDNA, anti-Ro, and anti-La), and cluster 3 (anti-dsDNA, LAC, and aCL). Patients in cluster 1 (n = 451), when compared with patients in clusters 2 (n = 470) and 3 (n = 436), had the lowest incidence of proteinuria (39.7%), anemia (52.8%), lymphopenia (33.9%), and thrombocytopenia (13.7%). The incidence of nephrotic syndrome and leukopenia was also lower in cluster 1 than in cluster 2. Cluster 2 had the highest female-to-male ratio (22:1) and the greatest proportion of Asian patients. Among the 3 clusters, cluster 2 had significantly more patients presenting with secondary Sjögren's syndrome (15.7%). Cluster 3, when compared with the other 2 clusters, consisted of more Caucasian and fewer African American patients and was characterized by the highest incidence of arterial thrombosis (17.4%), venous thrombosis (25.7%), and livedo reticularis (31.4%). By using the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index, the greatest frequency of nephrotic syndrome (8.9%) was observed in patients in cluster 2, whereas cluster 3 patients had the highest percentage of damage due to cerebrovascular accident (12.8%) and venous thrombosis (7.8%). Osteoporotic fracture (11.9%) was also more common in cluster 3 than in cluster 2.

CONCLUSION

Autoantibody clustering is a valuable tool to differentiate between various subsets of SLE, allowing prediction of subsequent clinical course and organ damage.

Human leukocyte antigen class II associations with systemic sclerosis in South Africans

Human leukocyte antigen class II typing, using polymerase chain reaction-sequence-specific primers, was performed in 52 Black South Africans with systemic sclerosis (SSc) and 112 controls. Increased frequencies of DR2 in the overall SSc group (OR = 2.4), DRB1*0301 in the limited cutaneous SSc (lcSSc) subset (OR = 9.0), and DQB1*0301/4 in the diffuse cutaneous SSc (dcSSc) subset (OR = 9.0) were observed. Pulmonary fibrosis was associated with DRB1*11 and anti-topoisomerase I antibodies were associated with DPB1*1301 and DRB1*15. Patients with anti-fibrillarin antibodies (AFAs) had increased the frequencies of DRB1*1101 allele group (OR = 16) and DQB1*0603/14 (OR = 13.6). These findings provide new serological and immunogenetic data on a previously unreported population. The association of AFAs with class II alleles merits further investigation.

Systemic lupus erythematosus in a patient with human immunodeficiency virus infection ? challenges in diagnosis and management

Systemic lupus erythematosus (SLE) is mainly a disease of young women. The problem of coexistent human immunodeficiency virus (HIV) infection is a growing problem in sub-Saharan Africa. We describe a case of active life-threatening neuropsychiatric lupus in a patient with underlying HIV infection. The challenges of interpreting physical signs and laboratory features that are common to both conditions, and the dilemma of treating active SLE with cytotoxics in the immunocompromised patient, are discussed.

Rapid clinical progression to diagnosis among African-American men with systemic lupus erythematosus

The initial clinical course of systemic lupus erythematosus (SLE) is variable, ranging from relatively minor manifestations progressing over years to rapid onset of fulminate disease. We sought to identify factors associated with the rapid manifestation of SLE. Chart review of military medical records was used to identify 130 patients who met the American College of Rheumatology classification criteria for SLE. Demographics, clinical criteria date of occurrence, and the date of SLE classification (at least four clinical criteria) met were documented. Prospectively stored serum samples prior to the diagnosis were evaluated for SLE autoantibodies. Median time from the first recorded criteria to diagnosis was significantly shorter in African-American (AA) males compared with AA females and European American (EA) females and males combined. AA males were more likely to have nephritis as their first clinical symptom. Also, less time transpired between the first clinical criterion and SLE diagnosis in AA males with nephritis than in other groups presenting with nephritis. Even when cases presenting with nephritis were excluded, a diagnosis of SLE was made more rapidly in AA males. African-American men progress from initial clinical manifestations to SLE diagnosis more rapidly than other ethnic or gender groups.

Scleroderma-like nailfold capillaroscopic abnormalities are associated with anti-U1-RNP antibodies and Raynaud's phenomenon in SLE patients

This study aimed to evaluate the association between nailfold capillary abnormalities and the presence of Raynaud's phenomenon (RP), anti-U1-RNP, and anti-cardiolipin (aCL) antibodies in SLE patients. One-hundred SLE patients were studied. Widefield nailfold capillaroscopy was considered abnormal according to five criteria. Intercapillary distance, capillary width and capillary length were registered by videomorphometry in two fingers in 100 patients and in four fingers in 40 of these patients. Both the presence of alterated capillaroscopy and the presence of scleroderma-pattern (SD-pattern), characterized by the presence of avascular areas and enlarged or giant loops, were associated with the isolated presence of RP (P < 0.001) or anti-U1-RNP antibodies (P < 0.01), as well as with the simultaneous presence of RP and anti-U1RNP antibodies (P < 0.001). There was a negative association between the presence of aCL antibodies and SD-pattern (P < 0.05). Higher figures for the videomorphometric parameters capillary width, intercapillary distance and capillary length (measured on four fingers) were observed in patients with RP. Patients presenting both RP and anti-U1-RNP antibodies showed higher figures for intercapillary distance and capillary width. This study demonstrated significant association between nailfold capillaroscopic abnormalities and either RP or anti-U1-RNP antibodies in SLE patients. The association of RP, anti-U1-RNP antibodies, and 'scleroderma-like' findings on nailfold capillaroscopy (SD-pattern) in patients with SLE may suggest a new SLE subset with subclinical features of systemic sclerosis.

Cluster analysis of antinuclear autoantibodies in the prognosis of SLE nephropathy: are anti-extractable nuclear antibodies protective?

To investigate the possible role of anti-ENA autoantibodies in the pathogenesis of SLE nephropathy, we performed a cross sectional clustering study of 91 SLE patients using 75 clinical and laboratory variables examining the presence of anti-dsDNA and ENA autoantibodies by ELISA and Western blot. We applied principal component, hierarchical cluster, multiple correspondence and logistical regression analysis. Two polar forms of SLE nephropathy and five clinical groups were identified: group 1 without overt nephropathy (n = 37), group 2 with nephropathy and only proteinuria (n = 19), group 3 nephropathy and only hematuria (n = 11), group 4 with hematuria and proteinuria (n = 14) and group 5 on renal failure (n = 10). When analyzed individually, levels of anti-dsDNA and single anti-ENA antibodies did not allow us to differentiate between renal and non-renal groups. However, when the anti-ENA autoantibodies were analyzed as a cluster, a high predictive value for clinical nephropathy was obtained. Thus, the absence of ENA antibodies (ENA ve or Venezuelan cluster) increased eleven-fold the odds ratio to develop SLE nephropathy. We suggested that the ENA ve cluster may predict development of the most severe forms of renal lupus while the ENA Sm/RNP and the ENA Ro/La/Sm/RNP clusters could be associated with the absence and the most benign form of SLE nephropathy. It must be interesting to apply similar cluster methodology in an SLE population with different ethnic background.

The use of laboratory tests in the diagnosis of SLE

ANA IIF is an effective screening assay in patients with clinical features of SLE and will detect most anti-ssDNA, anti-dsDNA, ENAs, and other autoantibodies. False positives are common. The clinical importance cannot be extrapolated from the ANA titre or pattern, although higher titres (> 1/160) are more likely to be important. HEp-2 cells are the most sensitive substrate for ANA detection, but this must be balanced against an increased incidence of insignificant positivity. ANA positive samples should be subjected to more specific assays for the diagnosis of SLE. A combination of ENA (Ro/La/Sm/RNP) and dsDNA assays will detect most patients with SLE as long as the characteristics of the assays used are well understood. ESR and CRP measurements provide useful additional information. Sjogren's syndrome and MCTD will produce overlapping serology with SLE, and anti-dsDNA titres are sometimes seen in autoimmune hepatitis and rheumatoid arthritis. All results should be reported in the light of the clinical details, by an experienced immunologist. A suggested diagnostic protocol is outlined in fig 1. The type of assay used crucially influences the predictive value of the tests. ELISA technology dominates routine laboratory practice, but tends to produce more false positive and true weak positive results, which may reduce the PPV of the test. This can be minimised by using IgG specific conjugates and careful assay validation. The NPV for SLE [figure: see text] is high for most assays but the PPV varies. Where necessary, laboratories should use crithidia or Farr dsDNA assays to confirm dubious ELISA dsDNA results, and ID/IB to confirm dubious ENA results. For monitoring, a precise, quantitative assay is required. It is unclear whether the detection of IgM or low affinity antibodies has a role here. A combination of anti-dsDNA, C3, C4, CRP, and ESR assays provides the most useful clinical information. Anti-ssDNA assays are likely to be useful, and are potentially more robust than anti-dsDNA assays, but require more validation. Local validation of individual assays and EQA participation is essential. Not all assays that apparently measure the same antibody specificities have equal clinical relevance, even within a single technology. Insufficient international or national reference preparations are currently available for many antibody specificities to enable effective standardisation. Quality assurance schemes reveal large differences in units reported by different assays for some analytes, even when calibrated against an IRP or equivalent reference preparation. Serial results can therefore only be compared from the same laboratory at present. Most autoantibodies increase during active disease, but few prospective data are currently available to justify treatment on the basis of rising titres. Further randomised prospective studies are required to examine the importance of antibody isotype and affinity in the monitoring of SLE by individual assay methods. The most important aspect of the appropriate use of laboratory assays is to become familiar with the limitations of the technology currently in use in your local laboratory, and to consult with your clinical immunologist in cases of doubt, preferably before commencing serological screening.

RNP positivity in Maltese SLE patients

The SLE database at the Rheumatology Clinic, St. Luke's Hospital currently includes 62 patients. The presentation, clinical features, ACR criteria and laboratory findings in RNP positive lupus patients [14] were compared to RNP negative subgroup [33]. RNP positivity was significantly associated with Raynaud's phenomenon (p < 0.01), myalgia (p < 0.02), myositis (p < 0.05), neuropsychiatric features (p < 0.05) and Sm positivity (p < 0.01). RNP positive patients had a higher frequency of positive family history, mortality, malar and maculopapular rashes, nail-fold infarcts, telangiectasia, digital vasculitis, photo-sensitivity, arthritis, pleurisy, pericarditis, pericardial effusions, depression, headache, psychosis and TIA.

Mucocutaneous disease in Arabs with systemic lupus erythematosus: clinical expression and relevance to autoantibodies

Both criterial and non-criterial mucocutaneous manifestations of 42 Arabs with systemic lupus erythematosus are reviewed. Photosensitivity occurred in 40.5%, malar rash in 35.75% and oral ulcers in 26% of patients. Subcutaneous nodules and subcutaneous lupus erythematosus (SCLE) were not seen, and there were few cases of discoid rash (DLE), Raynaud's phenomenon, livedo reticularis and SLE-related sicca and anticardiolipin syndromes. In the clinical relevance of autoantibodies in these patients, there was a significant association between anti-Sm antibodies and oral ulcers (P= 0.033) and, interestingly, between anti-cardiolipin (aCL) antibodies and lack of photosensitivity (P = 0.014). The report also reviews previously presented data on mucocutaneous LE in Arab and non-Arab patients and emphasises the presence of intra- and inter-racial variations of SLE expression including the clinical relevance to autoantibodies.

Genetic Determinants of Autoimmune Disease and Coronary Vasculitis in the MRL-lpr/lpr Mouse Model of Systemic Lupus Erythematosus

MRL-lpr/lpr (MRL/lpr) mice are a model of human autoimmune disease. They exhibit a number of characteristics of systemic lupus erythematosus, including anti-DNA Abs, anti-cardiolipin Abs, immune complex-mediated vasculitis, lymphadenopathy, and severe glomerulonephritis. Although the autoimmune disorder is mediated primarily by mutation of the Fas gene (lpr), which interferes with lymphocyte apoptosis, MRL/lpr mice also have other predisposing genetic factors. In an effort to identify these additional factors, we have applied quantitative trait locus (QTL) mapping using an intercross between MRL/lpr mice and the nonautoimmune inbred strain BALB/cJ. A complete linkage map spanning the entire genome was constructed for 189 intercross progeny, and genetic loci contributing to features of the autoimmunity were identified using statistical analytic procedures. As expected, the primary genetic determinant of autoimmune disease in this cross was the Fas gene on mouse chromosome 19, exhibiting a lod score of 60. In addition, two novel loci, one on chromosome 2 (lod score, 4.3) and one on chromosome 11 (lod score, 3.1), were found to contribute to levels of anti-DNA Abs. Interestingly, the chromosome 19 and chromosome 11 QTLs, but not the chromosome 2 QTL, also exhibited associations with anti-cardiolipin Abs (lod scores, 38.4 and 2.6). We further examined the effects of these QTLs on the development of coronary vasculitis in the F2 mice. Our results indicate that the QTLs on chromosomes 11 and 19 also control the development of vasculitis, demonstrating common genetic determinants of autoantibody levels and vasculitis.