Time to diagnosis in systemic lupus erythematosus: Associated factors and its impact on damage accrual and mortality. Data from a multi-ethnic, multinational Latin American lupus cohort.

BACKGROUND: Systemic lupus erythematosus (SLE) often mimics symptoms of other diseases, and the interval between symptom onset and diagnosis may be long in some of these patients. Aims: To describe the characteristics associated with the time to SLE diagnosis and its impact on damage accrual and mortality in patients with SLE from a Latin American inception cohort. METHODS: Patients were from a multi-ethnic, multi-national Latin-American SLE inception cohort. All participating centers had specialized lupus clinics. Socio-demographic, clinical/laboratory, disease activity, damage, and mortality between those with a longer and a shorter time to diagnosis were compared using descriptive statistical tests. Multivariable Cox regression models with damage accrual and mortality as the end points were performed, adjusting for age at SLE diagnosis, gender, ethnicity, level of education, and highest dose of prednisone for damage accrual, plus highest dose of prednisone, baseline SLEDAI, and baseline SDI for mortality. RESULTS: Of the 1437 included in these analyses, the median time to diagnosis was 6.0 months (Q1-Q3 2.4-16.2); in 721 (50.2%) the time to diagnosis was longer than 6 months. Patients whose diagnosis took longer than 6 months were more frequently female, older at diagnosis, of Mestizo ethnicity, not having medical insurance, and having "non-classic" SLE symptoms. Longer time to diagnosis had no impact on either damage accrual (HR 1.09, 95% CI 0.93-1.28, p = 0.300) or mortality (HR 1.37, 95% CI 0.88-2.12, p = 0.200). CONCLUSIONS: In this inception cohort, a maximum time of 24 months with a median of 6 months to SLE diagnosis had no apparent negative impact on disease outcomes (damage accrual and mortality).

Seguridad de las drogas biológicas y sintéticas dirigidas utilizadas en pacientes con enfermedades reumáticas inmunomediadas. Datos del registro BIOBADASAR 3.0 / Safety of biological and targeted synthetic drugs in patients with immune-mediated rheumatic diseases. Data from the BIOBADASAR 3.0 registry

Introducción: conocer la seguridad de las drogas actualmente disponibles para el tratamiento de las enfermedades reumáticas es muy importante al momento de tomar decisiones terapéuticas objetivas e individualizadas en la consulta médica diaria. Asimismo, datos de la vida real amplían el conocimiento revelado por los ensayos clínicos. Objetivos: describir los eventos adversos (EA) reportados, estimar su frecuencia e identificar los factores relacionados con su desarrollo. Materiales y métodos: se utilizaron datos BIOBADASAR, un registro voluntario y prospectivo de seguimiento de EA de tratamientos biológicos y sintéticos dirigidos en pacientes con enfermedades reumáticas inmunomediadas. Los pacientes son seguidos hasta la muerte, pérdida de seguimiento o retiro del consentimiento informado. Para este análisis se extrajeron datos recopilados hasta el 31 de enero de 2023. Resultados: se incluyó un total de 6253 pacientes, los cuales aportaron 9533 ciclos de tratamiento, incluyendo 3647 (38,3%) ciclos sin drogas modificadoras de la enfermedad biológicas y sintéticas dirigidas (DME-b/sd) y 5886 (61,7%) con DME-b/sd. Dentro de estos últimos, los más utilizados fueron los inhibidores de TNF y abatacept. Se reportaron 5890 EA en un total de 2701 tratamientos (844 y 1857 sin y con DME-b/sd, respectivamente), con una incidencia de 53,9 eventos cada 1000 pacientes/año (IC 95% 51,9-55,9). La misma fue mayor en los ciclos con DME-b/sd (71,1 eventos cada 1000 pacientes/año, IC 95% 70,7-77,5 versus 33,7, IC 95% 31,5-36,1; p<0,001). Las infecciones, particularmente las de la vía aérea superior, fueron los EA más frecuentes en ambos grupos. El 10,9% fue serio y el 1,1% provocó la muerte del paciente. El 18,7% de los ciclos con DME-b/sd fue discontinuado a causa de un EA significativamente mayor a lo reportado en el otro grupo (11,5%; p<0,001). En el análisis ajustado, las DME-b/sd se asociaron a mayor riesgo de presentar al menos un EA (HR 1,82, IC 95% 1,64-1,96). De igual manera, la mayor edad, el mayor tiempo de evolución, el antecedente de enfermedad pulmonar obstructiva crónica, el diagnóstico de lupus eritematoso sistémico y el uso de corticoides se asociaron a mayor riesgo de EA. Conclusiones: la incidencia de EA fue significativamente superior durante los ciclos de tratamientos que incluían DME-b/sd.

Introduction: knowing the efficacy and safety of the drugs currently available for the treatment of rheumatic diseases is very important when making objective and individualized therapeutic decisions in daily medical consultation. Likewise, real-life data extends the knowledge revealed by clinical trials. Objectives: to describe the reported adverse events (AEs), estimate their frequency and identify factors associated to them. Materials and methods: BIOBADASAR data were used, which is a voluntary, prospective follow-up registry of AEs of biological and synthetic treatments in patients with immune-mediated rheumatic diseases. Patients are followed until death, loss of followup, or withdrawal of informed consent. To carry out this analysis, the data collected up to January 31, 2023 was extracted. Results: a total of 6253 patients were included, who contributed with 9533 treatment periods, including 3647 (38.3%) periods without b/ts-DMARDs and 5886 (61.7%) with b/ts-DMARDs. Among the latter, the most used were TNF inhibitors and abatacept. A total of 5890 AEs were reported in a total of 2701 treatments (844 and 1857 without and with b/ts-DMARDs, respectively), with an incidence of 53.9 events per 1000 patients/ year (95% CI 51.9-55.9). It was higher during the periods with b/ts-DMARDs (71.1 events per 1000 patients/year, 95% CI 70.7-77.5 vs 33.7, 95% CI 31.5-36.1, p<0.001). Infections, particularly those of the upper respiratory tract, were the most frequent AEs in both groups. 10.9% were severe and 1.1% were associated with the death of the patient. 18.7% of the periods with b/ts-DMARDs were discontinued due to an AE, significantly higher than that reported in the other group (11.5%; p<0.001). In the adjusted analysis, b/ts-DMARDs were associated with a higher risk of presenting at least one AE (HR 1.82, 95% CI 1.64-1.96). Similarly, older age, longer evolution time, history of chronic obstructive pulmonary disease, diagnosis of systemic lupus erythematosus, and use of corticosteroids were associated with a higher risk of AE. Conclusions: the incidence of AEs was significantly higher during those treatment periods that included DME-b/sd.

Associations of baseline use of biologic or targeted synthetic DMARDs with COVID-19 severity in rheumatoid arthritis: Results from the COVID-19 Global Rheumatology Alliance physician registry.

OBJECTIVE: To investigate baseline use of biologic or targeted synthetic (b/ts) disease-modifying antirheumatic drugs (DMARDs) and COVID-19 outcomes in rheumatoid arthritis (RA). METHODS: We analysed the COVID-19 Global Rheumatology Alliance physician registry (from 24 March 2020 to 12 April 2021). We investigated b/tsDMARD use for RA at the clinical onset of COVID-19 (baseline): abatacept (ABA), rituximab (RTX), Janus kinase inhibitors (JAKi), interleukin 6 inhibitors (IL-6i) or tumour necrosis factor inhibitors (TNFi, reference group). The ordinal COVID-19 severity outcome was (1) no hospitalisation, (2) hospitalisation without oxygen, (3) hospitalisation with oxygen/ventilation or (4) death. We used ordinal logistic regression to estimate the OR (odds of being one level higher on the ordinal outcome) for each drug class compared with TNFi, adjusting for potential baseline confounders. RESULTS: Of 2869 people with RA (mean age 56.7 years, 80.8% female) on b/tsDMARD at the onset of COVID-19, there were 237 on ABA, 364 on RTX, 317 on IL-6i, 563 on JAKi and 1388 on TNFi. Overall, 613 (21%) were hospitalised and 157 (5.5%) died. RTX (OR 4.15, 95% CI 3.16 to 5.44) and JAKi (OR 2.06, 95% CI 1.60 to 2.65) were each associated with worse COVID-19 severity compared with TNFi. There were no associations between ABA or IL6i and COVID-19 severity. CONCLUSIONS: People with RA treated with RTX or JAKi had worse COVID-19 severity than those on TNFi. The strong association of RTX and JAKi use with poor COVID-19 outcomes highlights prioritisation of risk mitigation strategies for these people.

A longitudinal multiethnic study of biomarkers in systemic lupus erythematosus: Launching the GLADEL 2.0 Study Group.

Introduction: After more than 20 years of sustained work, the Latin American Group for the Study of Lupus (GLADEL) has made a significant number of contributions to the field of lupus, not only in the differential role that race/ethnicity plays in its course and outcome but also in several other studies including the beneficial effects of using antimalarials in lupus patients and the development of consensus guidelines for the treatment of lupus in our region. Methods: A new generation of "Lupus Investigators" in more than 40 centers throughout Latin America has been constituted in order to continue the legacy of the investigators of the original cohort and to launch a novel study of serum and urinary biomarkers in patients with systemic lupus erythematosus. Results: So far, we have recruited 807 patients and 631 controls from 42 Latin-American centers including 339 patients with SLE without renal involvement, 202 patients with SLE with prevalent but inactive renal disease, 176 patients with prevalent and active renal disease and 90 patients with incident lupus nephritis. Conclusions: The different methodological aspects of the GLADEL 2.0 cohort are discussed in this manuscript, including the challenges and difficulties of conducting such an ambitious project.

Predictors of renal damage in systemic lupus erythematous patients: data from a multiethnic, multinational Latin American lupus cohort (GLADEL).

AIM: A decrease in proteinuria has been considered protective from renal damage in lupus nephritis (LN), but a cut-off point has yet to be established. The aim of this study was to identify the predictors of renal damage in patients with LN and to determine the best cut-off point for a decrease in proteinuria. METHODS: We included patients with LN defined clinically or histologically. Possible predictors of renal damage at the time of LN diagnosis were examined: proteinuria, low complement, anti-double-stranded DNA antibodies, red cell casts, creatinine level, hypertension, renal activity (assessed by the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI)), prednisone dose, immunosuppressive drugs and antimalarial use. Sociodemographic variables were included at baseline. Proteinuria was assessed at baseline and at 12 months, to determine if early response (proteinuria <0.8 g/day within 12 months since LN diagnosis) is protective of renal damage occurrence. Renal damage was defined as an increase of one or more points in the renal domain of The Systemic Lupus International Collaborating Clinics (SLICC)/American College of Rheumatology (ACR) Damage Index (SDI). Cox regression models using a backward selection method were performed. RESULTS: Five hundred and two patients with systemic lupus erythematosus patients were included; 120 patients (23.9%) accrued renal damage during their follow-up. Early response to treatment (HR=0.58), antimalarial use (HR=0.54) and a high SES (HR=0.25) were protective of renal damage occurrence, whereas male gender (HR=1.83), hypertension (HR=1.86) and the renal component of the SLEDAI (HR=2.02) were risk factors for its occurrence. CONCLUSIONS: Early response, antimalarial use and high SES were protective of renal damage, while male gender, hypertension and higher renal activity were risk factors for its occurrence in patients with LN.

Clinical features, damage accrual, and survival in patients with familial systemic lupus erythematosus: data from a multi-ethnic, multinational Latin American lupus cohort.

OBJECTIVES: This study aimed to compare the clinical features, damage accrual, and survival of patients with familial and sporadic systemic lupus erythematosus (SLE). METHODS: A multi-ethnic, multinational Latin American SLE cohort was studied. Familial lupus was defined as patients with a first-degree SLE relative; these relatives were interviewed in person or by telephone. Clinical variables, disease activity, damage, and mortality were compared. Odds ratios (OR) and 95% confidence intervals (CI) were estimated. Hazard ratios (HR) were calculated using Cox proportional hazard adjusted for potential confounders for time to damage and mortality. RESULTS: A total of 66 (5.6%) patients had familial lupus, and 1110 (94.4%) had sporadic lupus. Both groups were predominantly female, of comparable age, and of similar ethnic distribution. Discoid lupus (OR = 1.97; 95% CI 1.08-3.60) and neurologic disorder (OR = 1.65; 95% CI 1.00-2.73) were significantly associated with familial SLE; pericarditis was negatively associated (OR = 0.35; 95% CI 0.14-0.87). The SLE Disease Activity Index and Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI) were similar in both groups, although the neuropsychiatric (45.4% vs. 33.5%; p = 0.04) and musculoskeletal (6.1% vs. 1.9%; p = 0.02) domains of the SDI were more frequent in familial lupus. They were not retained in the Cox models (by domains). Familial lupus was not significantly associated with damage accrual (HR = 0.69; 95% CI 0.30-1.55) or mortality (HR = 1.23; 95% CI 0.26-4.81). CONCLUSION: Familial SLE is not characterized by a more severe form of disease than sporadic lupus. We also observed that familial SLE has a higher frequency of discoid lupus and neurologic manifestations and a lower frequency of pericarditis.

Remission and Low Disease Activity Status (LDAS) protect lupus patients from damage occurrence: data from a multiethnic, multinational Latin American Lupus Cohort (GLADEL).

OBJECTIVE: To evaluate disease activity statuses' (DAS') impact on systemic lupus erythematosus (SLE) outcomes. MATERIALS AND METHODS: Four DAS were defined: remission off-therapy: SLE Disease Activity Index (SLEDAI)=0, no prednisone or immunosuppressive drugs (IS); remission on-therapy: SLEDAI=0, prednisone ≤5 mg/day and/or IS (maintenance); low (L) DAS: SLEDAI ≤4, prednisone ≤7.5 mg/day and/or IS (maintenance); non-optimally controlled: SLEDAI >4 and/or prednisone >7.5 mg/day and/or IS (induction). Antimalarials were allowed in all. Predefined outcomes were mortality, new damage (increase of at least one Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) damage index (SDI) point) and severe new damage (increase of at least 3 SDI points). Univariable and multivariable Cox regression models were performed to define the impact of DAS, as time-dependent variable, on these outcomes. RESULTS: 1350 patients were included, 79 died during follow-up, 606 presented new and 177 severe new damage. In multivariable analyses, remission (on/off-therapy) was associated with a lower risk of new (HR 0.60; 95% CI 0.43 to 0.85), and of severe new damage (HR 0.32; 95% CI 0.15 to 0.68); low disease activity status (LDAS) was associated with a lower risk of new damage (HR 0.66; 95% CI 0.48 to 0.93) compared with non-optimally controlled. No significant effect on mortality was observed. CONCLUSIONS: Remission was associated with a lower risk of new and severe new damage; LDAS with a lower risk of new damage after adjusting for other damage confounders.

Transancestral mapping and genetic load in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is an autoimmune disease with marked gender and ethnic disparities. We report a large transancestral association study of SLE using Immunochip genotype data from 27,574 individuals of European (EA), African (AA) and Hispanic Amerindian (HA) ancestry. We identify 58 distinct non-HLA regions in EA, 9 in AA and 16 in HA (∼50% of these regions have multiple independent associations); these include 24 novel SLE regions (P<5 × 10-8), refined association signals in established regions, extended associations to additional ancestries, and a disentangled complex HLA multigenic effect. The risk allele count (genetic load) exhibits an accelerating pattern of SLE risk, leading us to posit a cumulative hit hypothesis for autoimmune disease. Comparing results across the three ancestries identifies both ancestry-dependent and ancestry-independent contributions to SLE risk. Our results are consistent with the unique and complex histories of the populations sampled, and collectively help clarify the genetic architecture and ethnic disparities in SLE.

Genome-Wide Association Study in an Amerindian Ancestry Population Reveals Novel Systemic Lupus Erythematosus Risk Loci and the Role of European Admixture.

OBJECTIVE: Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with a strong genetic component. We undertook the present work to perform the first genome-wide association study on individuals from the Americas who are enriched for Native American heritage. METHODS: We analyzed 3,710 individuals from the US and 4 countries of Latin America who were diagnosed as having SLE, and healthy controls. Samples were genotyped with HumanOmni1 BeadChip. Data on out-of-study controls genotyped with HumanOmni2.5 were also included. Statistical analyses were performed using SNPtest and SNPGWA. Data were adjusted for genomic control and false discovery rate. Imputation was performed using Impute2 and, for classic HLA alleles, HiBag. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated. RESULTS: The IRF5-TNPO3 region showed the strongest association and largest OR for SLE (rs10488631: genomic control-adjusted P [Pgcadj ] = 2.61 × 10(-29), OR 2.12 [95% CI 1.88-2.39]), followed by HLA class II on the DQA2-DQB1 loci (rs9275572: Pgcadj = 1.11 × 10(-16), OR 1.62 [95% CI 1.46-1.80] and rs9271366: Pgcadj = 6.46 × 10(-12), OR 2.06 [95% CI 1.71-2.50]). Other known SLE loci found to be associated in this population were ITGAM, STAT4, TNIP1, NCF2, and IRAK1. We identified a novel locus on 10q24.33 (rs4917385: Pgcadj = 1.39 × 10(-8)) with an expression quantitative trait locus (eQTL) effect (Peqtl = 8.0 × 10(-37) at USMG5/miR1307), and several new suggestive loci. SLE risk loci previously identified in Europeans and Asians were corroborated. Local ancestry estimation showed that the HLA allele risk contribution is of European ancestral origin. Imputation of HLA alleles suggested that autochthonous Native American haplotypes provide protection against development of SLE. CONCLUSION: Our results demonstrate that studying admixed populations provides new insights in the delineation of the genetic architecture that underlies autoimmune and complex diseases.

Rheumatoid arthritis in Latin Americans enriched for Amerindian ancestry is associated with loci in chromosomes 1, 12, and 13, and the HLA class II region.

OBJECTIVE: To identify susceptibility loci for rheumatoid arthritis (RA) in Latin American individuals with admixed European and Amerindian genetic ancestry. METHODS: Genotyping was performed in 1,475 patients with RA and 1,213 control subjects, using a customized BeadArray containing 196,524 markers covering loci previously associated with various autoimmune diseases. Principal components analysis (EigenSoft package) and Structure software were used to identify outliers and define the population substructure. REAP software was used to define cryptic relatedness and duplicates, and genetic association analyses were conducted using Plink statistical software. RESULTS: A strong genetic association between RA and the major histocompatibility complex region was observed, localized within BTNL2/DRA-DQB1- DQA2 (P = 7.6 × 10(-10) ), with 3 independent effects. We identified an association in the PLCH2-HES5-TNFRSF14-MMEL1 region of chromosome 1 (P = 9.77 × 10(-6) ), which was previously reported in Europeans, Asians, and Native Canadians. We identified one novel putative association in ENOX1 on chromosome 13 (P = 3.24 × 10(-7) ). Previously reported associations were observed in the current study, including PTPN22, SPRED2, STAT4, IRF5, CCL21, and IL2RA, although the significance was relatively moderate. Adjustment for Amerindian ancestry improved the association of a novel locus in chromosome 12 at C12orf30 (NAA25) (P = 3.9 × 10(-6) ). Associations with the HLA region, SPRED2, and PTPN22 improved in individuals positive for anti-cyclic citrullinated peptide antibodies. CONCLUSION: Our data define, for the first time, the contribution of Amerindian ancestry to the genetic architecture of RA in an admixed Latin American population by confirming the role of the HLA region and supporting the association with a locus in chromosome 1. In addition, we provide data for novel putative loci in chromosomes 12 and 13.

Antimalarial treatment may have a time-dependent effect on lupus survival: data from a multinational Latin American inception cohort.

OBJECTIVE: To evaluate the beneficial effect of antimalarial treatment on lupus survival in a large, multiethnic, international longitudinal inception cohort. METHODS: Socioeconomic and demographic characteristics, clinical manifestations, classification criteria, laboratory findings, and treatment variables were examined in patients with systemic lupus erythematosus (SLE) from the Grupo Latino Americano de Estudio del Lupus Eritematoso (GLADEL) cohort. The diagnosis of SLE, according to the American College of Rheumatology criteria, was assessed within 2 years of cohort entry. Cause of death was classified as active disease, infection, cardiovascular complications, thrombosis, malignancy, or other cause. Patients were subdivided by antimalarial use, grouped according to those who had received antimalarial drugs for at least 6 consecutive months (user) and those who had received antimalarial drugs for <6 consecutive months or who had never received antimalarial drugs (nonuser). RESULTS: Of the 1,480 patients included in the GLADEL cohort, 1,141 (77%) were considered antimalarial users, with a mean duration of drug exposure of 48.5 months (range 6-98 months). Death occurred in 89 patients (6.0%). A lower mortality rate was observed in antimalarial users compared with nonusers (4.4% versus 11.5%; P< 0.001). Seventy patients (6.1%) had received antimalarial drugs for 6-11 months, 146 (12.8%) for 1-2 years, and 925 (81.1%) for >2 years. Mortality rates among users by duration of antimalarial treatment (per 1,000 person-months of followup) were 3.85 (95% confidence interval [95% CI] 1.41-8.37), 2.7 (95% CI 1.41-4.76), and 0.54 (95% CI 0.37-0.77), respectively, while for nonusers, the mortality rate was 3.07 (95% CI 2.18-4.20) (P for trend < 0.001). After adjustment for potential confounders in a Cox regression model, antimalarial use was associated with a 38% reduction in the mortality rate (hazard ratio 0.62, 95% CI 0.39-0.99). CONCLUSION: Antimalarial drugs were shown to have a protective effect, possibly in a time-dependent manner, on SLE survival. These results suggest that the use of antimalarial treatment should be recommended for patients with lupus.

Childhood systemic lupus erythematosus in Latin America. The GLADEL experience in 230 children.

To evaluate disease characteristics of childhood onset SLE in Latin America and to compare this information with an adult population in the same cohort of GLADEL. A protocol was designed as a multicenter, multinational, inception cohort of lupus patients to evaluate demographic, clinical, laboratory and serological variables, as well as classification criteria, disease activity, organ damage and mortality. Descriptive statistics, chi square, Fisher's exact test, Student's t test and multiple logistic regression were used to compare childhood and adult onset SLE. 230 patients were <18 years and 884 were adult SLE patients. Malar rash, fever, oral ulcers, thrombocytopenia and hemolytic anemia and some neurologic manifestations were more prevalent in children (p<0.05). On the other hand, myalgias, Sjögren's syndrome and cranial nerve involvement were more frequently seen in adults (p<0.05). Afro-Latin-American children had a higher prevalence of fever, thrombocytopenia and hemolytic anemia. White and mestizo children had a higher prevalence of malar rash. Mestizo children had a higher prevalence of cerebrovascular disease and cranial nerve involvement. Children met SLE ACR criteria earlier with higher mean values than adults (p: 0.001). They also had higher disease activity scores (p: 0.01), whereas adults had greater disease damage (p: 0.02). In Latin America, childhood onset SLE seems to be a more severe disease than adults. Some differences can be detected among ethnic groups.

Argentine population genetic structure: large variance in Amerindian contribution.

Argentine population genetic structure was examined using a set of 78 ancestry informative markers (AIMs) to assess the contributions of European, Amerindian, and African ancestry in 94 individuals members of this population. Using the Bayesian clustering algorithm STRUCTURE, the mean European contribution was 78%, the Amerindian contribution was 19.4%, and the African contribution was 2.5%. Similar results were found using weighted least mean square method: European, 80.2%; Amerindian, 18.1%; and African, 1.7%. Consistent with previous studies the current results showed very few individuals (four of 94) with greater than 10% African admixture. Notably, when individual admixture was examined, the Amerindian and European admixture showed a very large variance and individual Amerindian contribution ranged from 1.5 to 84.5% in the 94 individual Argentine subjects. These results indicate that admixture must be considered when clinical epidemiology or case control genetic analyses are studied in this population. Moreover, the current study provides a set of informative SNPs that can be used to ascertain or control for this potentially hidden stratification. In addition, the large variance in admixture proportions in individual Argentine subjects shown by this study suggests that this population is appropriate for future admixture mapping studies.

Chromosome 17p12-q11 harbors susceptibility loci for systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the presence of autoantibodies against intracellular components, the formation of immune complexes, and inflammation in various organs, typically the skin and kidney glomeruli. The etiology of the disease is not well understood but is most likely the result of the interaction between genetic and environmental factors. In order to identify susceptibility loci for SLE, we have performed genome scans with microsatellite markers covering the whole genome in families from Argentina, Italy, and Europe. The results reveal a heterogeneous disease with different susceptibility loci in different family sets. We have found significant linkage to chromosome 17p12-q11 in the Argentine set of families. The maximum LOD score was given by marker D17S1294 in combination with D17S1293, when assuming a dominant inheritance model (Z = 3.88). We also analyzed a repeat in the promoter region of the NOS2A gene, a strong candidate gene in the region, but no association was found. The locus on chromosome 17 has previously been identified in genetic studies of multiple sclerosis families. Several other interesting regions were found at 1p35, 1q31, 3q26, 5p15, 11q23 and 19q13, confirming previously identified loci for SLE or other autoimmune diseases.