Pre-pregnancy gene expression signatures are associated with subsequent improvement/worsening of rheumatoid arthritis during pregnancy.

BACKGROUND: While many women with rheumatoid arthritis (RA) improve during pregnancy and others worsen, there are no biomarkers to predict this improvement or worsening. In our unique RA pregnancy cohort that includes a pre-pregnancy baseline, we have examined pre-pregnancy gene co-expression networks to identify differences between women with RA who subsequently improve during pregnancy and those who worsen. METHODS: Blood samples were collected before pregnancy (T0) from 19 women with RA and 13 healthy women enrolled in our prospective pregnancy cohort. RA improvement/worsening between T0 and 3rd trimester was assessed by changes in the Clinical Disease Activity Index (CDAI). Pre-pregnancy expression profiles were examined by RNA sequencing and differential gene expression analysis. Weighted gene co-expression network analysis (WGCNA) was used to identify co-expression modules correlated with the improvement/worsening of RA during pregnancy and to assess their functional relevance. RESULTS: Of the 19 women with RA, 14 improved during pregnancy (RAimproved) while 5 worsened (RAworsened). At the T0 baseline, however, the mean CDAI was similar between the two groups. WGCNA identified one co-expression module related to B cell function that was significantly correlated with the worsening of RA during pregnancy and was significantly enriched in genes differentially expressed between the RAimproved and RAworsened groups. A neutrophil-related expression signature was also identified in the RAimproved group at the T0 baseline. CONCLUSION: The pre-pregnancy gene expression signatures identified represent potential biomarkers to predict the subsequent improvement/worsening of RA during pregnancy, which has important implications for the personalized treatment of RA during pregnancy.

Pregnancy-associated systemic gene expression compared to a pre-pregnancy baseline, among healthy women with term pregnancies.

Background: Pregnancy is known to induce extensive biological changes in the healthy mother. Little is known, however, about what these changes are at the molecular level. We have examined systemic expression changes in protein-coding genes and long non-coding (lnc) RNAs during and after pregnancy, compared to before pregnancy, among healthy women with term pregnancies. Methods: Blood samples were collected from 14 healthy women enrolled in our prospective pregnancy cohort at 7 time-points (before, during and after pregnancy). Total RNA from frozen whole blood was used for RNA sequencing. Following raw read alignment and assembly, gene-level counts were obtained for protein-coding genes and long non-coding RNAs. At each time-point, cell type proportions were estimated using deconvolution. To examine associations between pregnancy status and gene expression over time, Generalized Estimating Equation (GEE) models were fitted, adjusting for age at conception, and with and without adjusting for changes in cell type proportions. Fold-changes in expression at each trimester were examined relative to the pre-pregnancy baseline. Results: Numerous immune-related genes demonstrated pregnancy-associated expression, in a time-dependent manner. The genes that demonstrated the largest changes in expression included several that were neutrophil-related (over-expressed) and numerous immunoglobulin genes (under-expressed). Estimated cell proportions revealed a marked increase in neutrophils, and less so of activated CD4 memory T cells, during pregnancy, while most other cell type proportions decreased or remained unchanged. Adjusting for cell type proportions in our model revealed that although most of the expression changes were due to changes in cell type proportions in the bloodstream, transcriptional regulation was also involved, especially in down-regulating expression of type I interferon inducible genes. Conclusion: Compared to a pre-pregnancy baseline, there were extensive systemic changes in cell type proportions, gene expression and biological pathways associated with different stages of pregnancy and postpartum among healthy women. Some were due to changes in cell type proportions and some due to gene regulation. In addition to providing insight into term pregnancy among healthy women, these findings also provide a "normal" reference for abnormal pregnancies and for autoimmune diseases that improve or worsen during pregnancy, to assess deviations from normal.

Is gene expression among women with rheumatoid arthritis dysregulated during a postpartum flare?

BACKGROUND: To evaluate our hypotheses that, when rheumatoid arthritis (RA) flares postpartum, gene expression patterns are altered compared to (a) healthy women, (b) RA women whose disease activity is low or in remission postpartum, and (c) pre-pregnancy expression profiles. METHODS: Twelve women with RA and five healthy women were included in this pilot study. RA disease activity and postpartum flare were assessed using the Clinical Disease Activity Index (CDAI). Total RNA from frozen whole blood was used for RNA sequencing. Differential gene expression within the same women (within-group) over time, i.e., postpartum vs. third trimester (T3) or pre-pregnancy (T0), were examined, using a significance threshold of q < 0.05 and fold-change ≥ 2. RESULTS: Nine of the women with RA experienced a flare postpartum (RAFlare), while three had low disease activity or were in remission (RANoFlare) during that time frame. Numerous immune-related genes were differentially expressed postpartum (vs. T3) during a flare. Fold-changes in expression from T3 to postpartum were mostly comparable between the RAFlare and healthy groups. At 3 months postpartum, compared to healthy women, several genes were significantly differentially expressed only among the RAFlare women, and not among the RANoFlare women. Some of these genes were among those whose "normal" expression was significantly modulated postpartum, and the postpartum expression patterns were significantly altered during the RA flare. There were also some genes that were significantly differentially expressed in RAFlare compared to both healthy and RANoFlare women, even though their expression was not significantly modulated postpartum. Furthermore, while postpartum expression profiles were similar to those at pre-pregnancy among healthy women, significant differences were found between those time points among the RAFlare women. CONCLUSIONS: The large majority of gene expression changes between T3 and 3 months postpartum among RA women who flared postpartum reflected normal postpartum changes also seen among healthy women. Nonetheless, during a postpartum flare, a set of immune-related genes showed dysregulated expression compared to healthy women and women with RA whose disease activity was low or in remission during the same time frame, while other genes demonstrated significant differences in expression compared to RA pre-pregnancy levels.

The Rheumatoid Arthritis Gene Expression Signature Among Women Who Improve or Worsen During Pregnancy: A Pilot Study.

OBJECTIVE: To assess whether gene expression signatures associated with rheumatoid arthritis (RA) before pregnancy differ between women who improve or worsen during pregnancy, and to determine whether these expression signatures are altered during pregnancy when RA improves or worsens. METHODS: Clinical data and blood samples were collected before pregnancy (T0) and at the third trimester (T3) from 11 women with RA and 5 healthy women. RA disease activity was assessed using the Clinical Disease Activity Index (CDAI). At each timepoint, RA-associated gene expression signatures were identified using differential expression analysis of RNA sequencing profiles between women with RA and healthy women. RESULTS: Of the women with RA, 6 improved by T3 (RAimproved), 3 worsened (RAworsened),and 2 were excluded. At T0, mean CDAI scores were similar in both groups (RAimproved 11.2 ± 9.8; RAworsened 13.8 ± 6.7; Wilcoxon rank-sum test: P = 0.6). In the RAimproved group, 89 genes were differentially expressed at T0 (q < 0.05 and fold change ≥ 2) compared to healthy women. When RA improved at T3, 65 of 89 (73%) of these genes no longer displayed RA-associated expression. In the RAworsened group, a largely different RA gene expression signature (429 genes) was identified at T0. When RA disease activity worsened at T3, 207 of 429 (48%) genes lost their differential expression, while an additional 151 genes became newly differentially expressed. CONCLUSION: In our pilot dataset, pre-pregnancy RA expression signatures differed between women who subsequently improved or worsened during pregnancy, suggesting that inherent genomic differences may influence how pregnancy affects disease activity. Further, these RA signatures were altered during pregnancy as disease activity changed.

Parental Rheumatoid Arthritis and Autism Spectrum Disorders in Offspring: A Danish Nationwide Cohort Study.

OBJECTIVE: Maternal rheumatoid arthritis (RA) has been associated with an increased risk of autism spectrum disorder (ASD) in the offspring. We assessed the potential influence of both maternal and paternal RA on the risk of ASD in offspring to disentangle the influence of genetic inheritance from other conditions potentially leading to fetal programming. METHOD: The nationwide cohort study included all children born alive from 1977 to 2008 in Denmark (N = 1,917,723). Cox regression models were used to calculate hazard rate ratios (HR) of ASD in offspring exposed to maternal or paternal RA, compared to unexposed children. RESULTS: Maternal RA was associated with an approximately 30% increased risk of ASD in the offspring (HR = 1.31 and 95% CI = 1.06-1.63). Also, paternal RA seemed to increase the risk of ASD by approximately 30% (HR = 1.33, 95% CI = 0.97-1.82). CONCLUSION: Our findings suggest maternal as well as paternal RA to be associated with an increased risk of ASD in the offspring, indicating that genetic factors associated with RA may also play a role in the etiology of ASD in children of parents with RA.

Pregnancy-induced gene expression changes in vivo among women with rheumatoid arthritis: a pilot study.

BACKGROUND: Little is known about gene expression changes induced by pregnancy in women with rheumatoid arthritis (RA) and healthy women because the few studies previously conducted did not have pre-pregnancy samples available as baseline. We have established a cohort of women with RA and healthy women followed prospectively from a pre-pregnancy baseline. In this study, we tested the hypothesis that pregnancy-induced changes in gene expression among women with RA who improve during pregnancy (pregDASimproved) overlap substantially with changes observed among healthy women and differ from changes observed among women with RA who worsen during pregnancy (pregDASworse). METHODS: Global gene expression profiles were generated by RNA sequencing (RNA-seq) from 11 women with RA and 5 healthy women before pregnancy (T0) and at the third trimester (T3). Among the women with RA, eight showed an improvement in disease activity by T3, whereas three worsened. Differential expression analysis was used to identify genes demonstrating significant changes in expression within each of the RA and healthy groups (T3 vs T0), as well as between the groups at each time point. Gene set enrichment was assessed in terms of Gene Ontology processes and protein networks. RESULTS: A total of 1296 genes were differentially expressed between T3 and T0 among the 8 pregDASimproved women, with 161 genes showing at least two-fold change (FC) in expression by T3. The majority (108 of 161 genes) were also differentially expressed among healthy women (q<0.05, FC≥2). Additionally, a small cluster of genes demonstrated contrasting changes in expression between the pregDASimproved and pregDASworse groups, all of which were inducible by type I interferon (IFN). These IFN-inducible genes were over-expressed at T3 compared to the T0 baseline among the pregDASimproved women. CONCLUSIONS: In our pilot RNA-seq dataset, increased pregnancy-induced expression of type I IFN-inducible genes was observed among women with RA who improved during pregnancy, but not among women who worsened. These findings warrant further investigation into expression of these genes in RA pregnancy and their potential role in modulation of disease activity. These results are nevertheless preliminary and should be interpreted with caution until replicated in a larger sample.

Parental Rheumatoid Arthritis, Child Mortality, and Case Fatality: A Nationwide Cohort Study.

OBJECTIVE: We have previously reported increased long-term morbidity in children of parents with rheumatoid arthritis (RA). Here we assess child mortality and case fatality in the same cohort. METHODS: All singletons born in Denmark from 1977 to 2008 were identified through linkage of Danish national registries. Cox proportional hazards models were used to calculate hazard ratios (HRs) of death from all causes among children exposed to parental RA, compared to unexposed children. Risk of death after infection or respiratory diseases was also assessed for children below the age of 5 years. RESULTS: This study followed 1,917,723 newborns for an average of 16 years. Of these, 13,556 were exposed to maternal RA and 6,330 to paternal RA. Overall mortality rates in children exposed to maternal or paternal RA did not differ from those in unexposed children (HR 0.98 [95% confidence interval (95% CI) 0.84-1.15] and 1.08 [95% CI 0.86-1.36], respectively), nor did the risk of death below the ages of 5 years, 3 years, or 1 year. In the group of children below the age of 5 years, 6,106 children of parents with RA were diagnosed with respiratory diseases and 3,320 with infectious diseases. The case fatality rate in children with these diseases was not significantly higher than in unexposed children (HR 1.11 [95% CI 0.74-1.66] and 0.84 [95% CI 0.52-1.35], respectively). CONCLUSION: Children of parents with RA had similar mortality rates as other children, as well as after diagnoses of respiratory or infectious diseases.

Parental rheumatoid arthritis and childhood epilepsy: A nationwide cohort study.

OBJECTIVE: To assess the influence of parental rheumatoid arthritis (RA) on risk of epilepsy. METHODS: We performed a nationwide cohort study including all singletons born in Denmark from 1977 to 2008 (n = 1,917,723) through individual linkage to nationwide Danish registries. The children were followed for an average of 16 years. Main outcome measures were adjusted hazard ratios (HRs) for epilepsy with onset in early childhood (29 days-4 years), late childhood (5-15 years), adolescence/adulthood (≥15 years), and at any age until the end of follow-up (December 31, 2010). RESULTS: Compared to unexposed children, children exposed to maternal RA had an increased risk of early and late childhood epilepsy (adjusted HRs 1.34 [95% confidence interval (CI) 1.13-1.60] and 1.26 [95% CI 1.13-1.41]), while children exposed to maternal RA had no increased risk of epilepsy in adolescence/adulthood (HR 1.15 [95% CI 0.92-1.45]). Paternal RA was not associated with an overall risk of epilepsy in the offspring (HR 0.96 [95% CI 0.81-1.15]) or at any age. Children exposed to maternal RA in utero had a more pronounced increased risk of early childhood epilepsy than children exposed to mothers who were diagnosed with RA after childbirth (HR 1.90 [95% CI 1.26-2.86] vs HR 1.26 [95% CI 1.03-1.52], respectively [p = 0.16]). CONCLUSIONS: Exposure to maternal RA was associated with an increased risk of childhood epilepsy, while exposure to paternal RA was not, which indicates that changes in the intrauterine environment may play a role.

A longitudinal genome-wide association study of anti-tumor necrosis factor response among Japanese patients with rheumatoid arthritis.

BACKGROUND: Studies of Caucasian patients with rheumatoid arthritis (RA) to identify genetic biomarkers of anti-tumor necrosis factor (TNF) response have used response at a single time point as the phenotype with which single nucleotide polymorphism (SNP) associations have been tested. The findings have been inconsistent across studies. Among Japanese patients, only a few SNPs have been investigated. We report here the first genome-wide association study (GWAS) to identify genetic biomarkers of anti-TNF response among Japanese RA patients, using response at 2 time-points for a more reliable clinical phenotype over time. METHODS: Disease Activity Scores based on 28 joint counts (DAS28) were assessed at baseline (before initial therapy), and after 3 and 6 months in 487 Japanese RA patients starting anti-TNF therapy for the first time or switching to a new anti-TNF agent. A genome-wide panel of SNPs was genotyped and additional SNPs were imputed. Using change in DAS28 scores from baseline at both 3 (ΔDAS-3) and 6 months (ΔDAS-6) as the response phenotype, a longitudinal genome-wide association analysis was conducted using generalized estimating equations (GEE) models, adjusting for baseline DAS28, treatment duration, type of anti-TNF agent and concomitant methotrexate. Cross-sectional analyses were performed using multivariate linear regression models, with response from a single time point (ΔDAS-3 or ΔDAS-6) as phenotype; all other variables were the same as in the GEE models. RESULTS: In the GEE models, borderline significant association was observed at 3 chromosomal regions (6q15: rs284515, p = 6.6x10(-7); 6q27: rs75908454, p = 6.3x10(-7) and 10q25.3: rs1679568, p = 8.1x10(-7)), extending to numerous SNPs in linkage disequilibrium (LD) across each region. Potential candidate genes in these regions include MAP3K7, BACH2 (6q15), GFRA1 (10q25.3), and WDR27 (6q27). The association at GFRA1 replicates a previous finding from a Caucasian dataset. In the cross-sectional analyses, ΔDAS-6 was significantly associated with the 6q15 locus (rs284511, p = 2.5x10(-8)). No other significant or borderline significant associations were identified. CONCLUSION: Three genomic regions demonstrated significant or borderline significant associations with anti-TNF response in our dataset of Japanese RA patients, including a locus previously associated among Caucasians. Using repeated measures of response as phenotype enhanced the power to detect these associations.

Parental rheumatoid arthritis and long-term child morbidity: a nationwide cohort study.

OBJECTIVE: To estimate the influence of parental rheumatoid arthritis (RA) on child morbidity. DESIGN: Nationwide cohort study. SETTING: Individual linkage to nationwide Danish registries. PARTICIPANTS: All singletons born in Denmark during 1977-2008 (n=1 917 723) were followed for an average of 16 years. MAIN OUTCOME MEASURES: Adjusted HRs for child morbidity; that is, 11 main diagnostic groups and specific autoimmune diseases within the International Classification of Diseases 8th and 10th versions. RESULTS: Compared with unexposed children, children exposed to maternal RA ('clinical' and 'preclinical') (n=13 566) had up to 26% higher morbidity in 8 of 11 main diagnostic groups. Similar tendencies were found in children exposed to paternal RA ('clinical' and 'preclinical') (n=6330), with statistically significantly higher morbidity in 6 of 11 diagnostic groups. HRs were highest for autoimmune diseases with up to three times increased risk of juvenile idiopathic arthritis (HR, 95% CI 3.30, 2.71 to 4.03 and 2.97, 2.20 to 4.01) and increased risk of up to 40% of diabetes mellitus type 1 (HR, 95% CI 1.37, 1.12 to 1.66 and 1.44, 1.09 to 1.90) and up to 30% increased HR of asthma (HR, 95% CI 1.28, 1.20 to 1.36 and 1.15, 1.04 to 1.26). Conclusions were roughly similar for children exposed to maternal clinical RA and for children only followed up to 16 years of age. CONCLUSION: Children of parents with RA had consistent excess morbidity. If the associations reflect biological mechanisms, genetic factors seem to play an important role. These findings call for attention given to children of parents with RA.

Pregnancy-Induced Changes in Systemic Gene Expression among Healthy Women and Women with Rheumatoid Arthritis.

BACKGROUND: Pregnancy induces drastic biological changes systemically, and has a beneficial effect on some autoimmune conditions such as rheumatoid arthritis (RA). However, specific systemic changes that occur as a result of pregnancy have not been thoroughly examined in healthy women or women with RA. The goal of this study was to identify genes with expression patterns associated with pregnancy, compared to pre-pregnancy as baseline and determine whether those associations are modified by presence of RA. RESULTS: In our RNA sequencing (RNA-seq) dataset from 5 healthy women and 20 women with RA, normalized expression levels of 4,710 genes were significantly associated with pregnancy status (pre-pregnancy, first, second and third trimesters) over time, irrespective of presence of RA (False Discovery Rate (FDR)-adjusted p value<0.05). These genes were enriched in pathways spanning multiple systems, as would be expected during pregnancy. A subset of these genes (n = 256) showed greater than two-fold change in expression during pregnancy compared to baseline levels, with distinct temporal trends through pregnancy. Another 98 genes involved in various biological processes including immune regulation exhibited expression patterns that were differentially associated with pregnancy in the presence or absence of RA. CONCLUSIONS: Our findings support the hypothesis that the maternal immune system plays an active role during pregnancy, and also provide insight into other systemic changes that occur in the maternal transcriptome during pregnancy compared to the pre-pregnancy state. Only a small proportion of genes modulated by pregnancy were influenced by presence of RA in our data.

Fetal growth and preterm birth in children exposed to maternal or paternal rheumatoid arthritis: a nationwide cohort study.

OBJECTIVE: To assess indicators of fetal growth and risk of preterm birth in children of parents with rheumatoid arthritis (RA). METHODS: Through linkage of Danish national registries, we identified all children born in Denmark between 1977 and 2008. We used general linear regression models to estimate mean differences in indicators of fetal growth among children with a parent with RA compared to unexposed children. Odds ratios (ORs) and 95% confidence intervals (95% CIs) of preterm birth were calculated using a logistic regression model. RESULTS: Of the 1,917,723 children included, a total of 13,556 children were exposed to maternal RA or maternal preclinical RA. Children exposed to maternal RA (n = 2,101) had approximately similar length, head circumference, and abdominal circumference at birth compared with children of mothers without RA. Birth weight was 87 gm lower (mean difference -87.04 gm [95% CI -111.23, -62.84]) and placenta weight was 14 gm lower (-13.45 gm [95% CI -21.46, -5.43]) than those in children of mothers without RA. Rather similar results were found in children exposed to maternal preclinical RA (n = 11,455). Compared with unexposed children, a higher risk of preterm birth was found in children exposed to maternal RA (OR 1.48 [95% CI 1.20, 1.84]) and preclinical RA (OR 1.32 [95% CI 1.07, 1.64]). No associations were found with paternal RA. CONCLUSION: Children exposed to either maternal RA or maternal preclinical RA are more often born preterm. However, indicators of fetal growth measured at birth were only slightly lower than those in unexposed children.

Significance of sex in achieving sustained remission in the consortium of rheumatology researchers of North America cohort of rheumatoid arthritis patients.

OBJECTIVE: To determine whether men with rheumatoid arthritis (RA) are more likely to achieve remission compared to women. METHODS: RA patients enrolled in the Consortium of Rheumatology Researchers of North America (CORRONA) cohort between October 2001 and January 2010 were selected for the present analyses. Detailed clinical, demographic, and drug utilization data were available at enrollment (baseline) and at subsequent followup visits. We examined the influence of sex on the Clinical Disease Activity Index remission score (≤2.8) using sustained remission or point remission as the primary outcome measure in multivariate stepwise logistic regression models. We stratified the data by RA duration at baseline (≤2 years or >2 years) to investigate whether RA duration had differential effects on remission in men and women. RESULTS: A total of 10,299 RA patients (2,406 men and 7,893 women) were available for this study. In both early and established RA, women had more severe disease at baseline with worse disease activity measures, modified Health Assessment Questionnaire disability index score, pain on a visual analog scale, and depression. Women were also more likely to have been treated with disease-modifying antirheumatic drugs and anti-tumor necrosis factor therapy compared to men. In the regression models, male sex was associated with sustained remission in early RA (odds ratio [OR] 1.38, 95% confidence interval [95% CI] 1.07-1.78, P = 0.01), but not in established RA. However, for point remission, an inverse association was observed with male sex in established RA (OR 0.65, 95% CI 0.48-0.87, P = 0.005) and not in early RA. CONCLUSION: Within the large real-life CORRONA cohort of RA patients, men were more likely to achieve sustained remission compared to women in early RA, although not in established RA.

Sex differences in response to anti-tumor necrosis factor therapy in early and established rheumatoid arthritis -- results from the DANBIO registry.

OBJECTIVE: To investigate sex differences in response to anti-tumor necrosis factor-α (TNF-α) therapy over time in early versus established rheumatoid arthritis (RA). METHODS: Patients with RA who initiated anti-TNF therapy between January 2003 and June 2008 in Denmark were selected from the DANBIO Registry. Sex differences in baseline disease features were examined using chi-square, Mann-Whitney U tests, and t tests. Using a generalized estimating equations (GEE) model for repeated measures, we examined European League Against Rheumatism (EULAR) responses in men and women over 48 months of followup, adjusting for baseline values of age, 28-joint Disease Activity Score (DAS28), disease duration, and anti-TNF, methotrexate, and prednisolone use. RESULTS: At initiation of anti-TNF therapy (baseline), 328 women and 148 men had early RA (≤ 2 yrs), and 1245 women and 408 men had established RA (> 2 yrs). In both early and established RA, men and women had active disease with similar DAS28 scores (mean ± SD 5.2 ± 1.1), physician global scores, swollen joint counts, and radiographic changes. In early RA, men were significantly more likely to achieve a EULAR good/moderate response over 48 months compared to women (GEE; p = 0.003), and a significant interaction between sex and followup time (GEE; p < 0.0005) suggested that men achieved this response sooner than women. CONCLUSION: Better responses to anti-TNF therapy among men compared to women in early but not established RA suggest that disease duration at initiation of therapy may be an important factor to consider when investigating sex differences in treatment responses.

Time to pregnancy among women with rheumatoid arthritis.

OBJECTIVE: To assess whether onset of rheumatoid arthritis (RA) prior to conception is associated with a delayed time to pregnancy (TTP). METHODS: The study included pregnant women from across Denmark who enrolled in the Danish National Birth Cohort between 1996 and 2002 and had planned or partly planned the cohort pregnancy. RA diagnosis was identified using the Danish National Hospital Discharge Registry. Self-reported data, including TTP, maternal age, parity, prepregnancy height and weight, maternal occupational status, smoking, and alcohol consumption, were collected using a detailed computer-assisted telephone interview at ∼16 weeks of gestation. We used logistic regression analyses as well as a complementary log regression model to examine whether TTP was influenced by RA, adjusting for the abovementioned variables. RESULTS: Overall, compared with women with no recorded RA (n=74,255), women with prevalent RA (onset prior to conception) (n=112) were slightly older (mean±SD age 30.8±4.3 years versus 29.7±4.1 years), were more likely to have been treated for infertility (9.8% versus 7.6%), and were more likely to have taken>12 months to conceive (25.0% versus 15.6%). The association between RA and TTP was borderline significant after adjusting for covariates in the regression analyses (odds ratio 1.6 [95% confidence interval 1.0-2.4]). Similar results were obtained after restricting the analyses to women who had planned the pregnancy or those who were nulliparous before the cohort pregnancy. CONCLUSION: Women with RA onset prior to conception had a slightly longer TTP compared with those who did not have RA, indicating a slight reduction in fecundity.

Disease progression and treatment responses in a prospective DMARD-naive seropositive early rheumatoid arthritis cohort: does gender matter?

OBJECTIVE: To assess gender differences in disease characteristics and treatment responses over time in a disease-modifying antirheumatic drug (DMARD)-naive seropositive early rheumatoid arthritis (RA) cohort. METHODS: Patients with polyarticular disease who were DMARD-naive and had seropositive early RA (< 14 months) were recruited by the Western Consortium of Practicing Rheumatologists. Each patient was examined at study entry, after 6 and 12 months, and yearly thereafter. Clinical and demographic data were collected. We investigated gender differences in baseline disease characteristics and treatment using chi-squared, Mann-Whitney U, and t tests. We used generalized estimating equations (GEE) models for repeated measures to examine whether the rate of change of specific disease outcomes during the first 2 years after DMARD initiation was significantly influenced by gender. RESULTS: At baseline, men (n = 67) and women (n = 225) had similar disease activity and radiographic damage; men, however, had significantly worse erosion, while women had worse joint space narrowing. Despite similar treatment, women had worse disease progression over the 2-year followup, as assessed by trends in Disease Activity Score 28/erythrocyte sedimentation rate (DAS28-ESR4), physician global scores, and tender joint counts. In the GEE model, gender was significantly associated with the rate of change of DAS28-ESR4 scores (p = 0.009), although not independently associated with disease activity. Self-reported measures (Health Assessment Questionnaire-Disability Index, patient global scores, fatigue, pain) were worse among women at baseline and throughout the study period. Men were more likely to achieve remission. CONCLUSION: At baseline, men and women had similar disease activity and joint damage. Responses to treatment over time were better among men in this prebiologic era; women had worse progression despite similar treatment.

Comparison of composite measures of disease activity in an early seropositive rheumatoid arthritis cohort.

OBJECTIVE: To evaluate concordance and agreement of the original DAS44/ESR-4 item composite disease activity status measure with nine simpler derivatives when classifying patient responses by European League of Associations for Rheumatology (EULAR) criteria, using an early rheumatoid factor positive (RF+) rheumatoid arthritis (RA) patient cohort. METHODS: Disease-modifying anti-rheumatic drug-naïve RF+ patients (n = 223; mean duration of symptoms, 6 months) were categorised as ACR none/20/50/70 responders. One-way analysis of variance and two-sample t tests were used to investigate the relationship between the ACR response groups and each composite measure. EULAR reached/change cut-point scores were calculated for each composite measure. EULAR (good/moderate/none) responses for each composite measure and the degree of agreement with the DAS44/ESR-4 item were calculated for 203 patients. RESULTS: Patients were mostly female (78%) with moderate to high disease activity. A centile-based nomogram compared equivalent composite measure scores. Changes from baseline in the composite measures in patients with ACRnone were significantly less than those of ACR20/50/70 responders, and those for ACR50 were significantly different from those for ACR70. EULAR reached/change cut-point scores for our cohort were similar to published cut-points. When compared with the DAS44/ESR-4 item, EULAR (good/moderate/none) percentage agreements were 92 with the DAS44/ESR-3 item, 74 with the Clinical Disease Activity Index, and 80 with the DAS28/ESR-4 item, the DAS28/CRP-4 item and the Simplified Disease Activity Index. CONCLUSION: The relationships of nine different RA composite measures against the DAS44/ESR-4 item when applied to a cohort of seropositive patients with early RA are described. Each of these simplified status and response measures could be useful in assessing patients with RA, but the specific measure selected should be pre-specified and described for each study.

Dissecting the heterogeneity of rheumatoid arthritis through linkage analysis of quantitative traits.

OBJECTIVE: To dissect the heterogeneity of rheumatoid arthritis (RA) through linkage analysis of quantitative traits, specifically, IgM rheumatoid factor (IgM-RF) and anti-cyclic citrullinated peptide (anti-CCP) autoantibody titers. METHODS: Subjects, 1,002 RA patients from 491 multiplex families recruited by the North American RA Consortium, were typed for 379 microsatellite markers. Anti-CCP titers were determined based on a second-generation enzyme-linked immunosorbent assay, and IgM-RF levels were quantified by immunonephelometry. We used the Merlin statistical package to perform nonparametric quantitative trait linkage analysis. RESULTS: For each of the quantitative traits, evidence of linkage, with logarithm of odds (LOD) scores of >1.0, was found in 9 regions. For both traits, the strongest evidence of linkage was for marker D6S1629 on chromosome 6p (LOD 14.02 for anti-CCP and LOD 12.09 for RF). Six other regions with LOD scores of >1.0 overlapped between the 2 traits, on chromosomes 1p21.1, 5q15, 8p23.1, 16p12.1, 16q23.1, and 18q21.31. Evidence of linkage to anti-CCP titer but not to RF titer was found in 2 regions (chromosomes 9p21.3 and 10q21.1), and evidence of linkage to RF titer but not to anti-CCP titer was found in 2 regions (chromosomes 5p15.2 and 1q42.3). Several covariates were significantly associated with 1 or both traits, and linkage analysis exploring the covariate effects revealed striking effects of sex in modulating linkage signals for several chromosomal regions. For example, sex had a striking impact on the linkage results for both quantitative traits on chromosome 6p (P = 0.0007 for anti-CCP titer and P = 0.0012 for RF titer), suggesting a sex-HLA region interaction. CONCLUSION: Analysis of quantitative components of RA is a promising approach for dissecting the genetic heterogeneity of this complex disorder. These results highlight the potential importance of sex or other covariates that may modulate some of the genetic effects that influence the risk of specific disease manifestations.

Influence of male sex on disease phenotype in familial rheumatoid arthritis.

OBJECTIVE: To examine sex differences in clinical, demographic, and genetic characteristics among a large cohort of patients with familial rheumatoid arthritis (RA). METHODS: We studied 1,004 affected members of 467 Caucasian multicase RA families recruited from the North American Rheumatoid Arthritis Consortium. Standardized information about demographic and clinical characteristics was collected from all patients. Affected individuals also underwent radiography of the hands and were genotyped for markers in the HLA region. Sex differences were assessed using contingency table analysis (for categorical variables) and Student's t-tests for (continuous variables), and by multivariate logistic and linear regression analysis. RESULTS: Male patients had a significantly later onset of RA, were more likely to be seropositive for RF, and had significantly higher titers of anti-cyclic citrullinated peptide (anti-CCP) antibodies compared with female patients, even after adjustment for covariates in multivariate analyses. Male patients were also significantly more likely to have a history of smoking and to be HLA-DRB1 shared epitope (SE) positive. Interestingly, female patients with an affected male sibling had significantly higher titers of anti-CCP antibodies and were more likely to be SE positive compared with female patients without affected male siblings. Multivariate analyses indicated that the presence of the SE did not fully explain the increased anti-CCP antibody titers observed in these families. CONCLUSION: Sex has an important influence on the disease phenotype in RA, including the age at disease onset and autoantibody production. Furthermore, families with affected male members are characterized by higher titers of autoantibodies, particularly anti-CCP antibodies. Our results indicate that these findings are not fully explained by differences in exposure to tobacco smoke, presence of the HLA-DRB1 SE, or other HLA region genetic variation. Thus, other genetic or nongenetic factors also contribute to sex differences in the RA phenotype.

Convergent linkage evidence from two Latin-American population isolates supports the presence of a susceptibility locus for bipolar disorder in 5q31-34.

We performed a whole genome microsatellite marker scan in six multiplex families with bipolar (BP) mood disorder ascertained in Antioquia, a historically isolated population from North West Colombia. These families were characterized clinically using the approach employed in independent ongoing studies of BP in the closely related population of the Central Valley of Costa Rica. The most consistent linkage results from parametric and non-parametric analyses of the Colombian scan involved markers on 5q31-33, a region implicated by the previous studies of BP in Costa Rica. Because of these concordant results, a follow-up study with additional markers was undertaken in an expanded set of Colombian and Costa Rican families; this provided a genome-wide significant evidence of linkage of BPI to a candidate region of approximately 10 cM in 5q31-33 (maximum non-parametric linkage score=4.395, P<0.00004). Interestingly, this region has been implicated in several previous genetic studies of schizophrenia and psychosis, including disease association with variants of the enthoprotin and gamma-aminobutyric acid receptor genes.