Karin Hellgren

Do rheumatoid arthritis and lymphoma share risk factors?: A comparison of lymphoma and cancer risks before and after diagnosis of rheumatoid arthritis

OBJECTIVE Patients with rheumatoid arthritis (RA), in particular those with the most severe disease, are at increased risk of developing malignant lymphoma. Whether this increase is entirely a consequence of the RA disease and/or its treatment or is reflective of shared susceptibility to the two diseases remains unclear. We undertook this study to assess whether patients with RA are already at increased risk of lymphoma or of other cancers before the diagnosis of RA, and if the relative risk increases with time since RA diagnosis. METHODS Patients with incident RA (symptom duration <1 year) (n = 6,745) registered in the Swedish Early Arthritis Registry from 1997 through 2006 were identified. For each patient, 5 general population controls were randomly matched by sex, age, marital status, and residence (n = 33,657). For all study subjects, inclusion in the nationwide Swedish Cancer Register in 1958-2006 was determined. Relative risks (RRs) (with 95% confidence intervals [95% CIs]) of lymphoma and of cancer overall, before and after diagnosis of RA, were estimated using conditional logistic regression and Cox regression, respectively. RESULTS Before diagnosis of RA, there was no observed increase in the risk of lymphoma (RR [odds ratio] 0.67 [95% CI 0.37-1.23]) or other cancers (RR 0.78 [95% CI 0.70-0.88]). During the first 10 years following diagnosis of RA, the overall RR (hazard ratio) of lymphoma development was 1.75 (95 % CI 1.04-2.96). CONCLUSION These findings indicate that overall, a history of cancer, including lymphoma, does not increase the risk of subsequent RA development. Shared susceptibility to RA and lymphoma may thus be of limited importance. In contrast, increased lymphoma risks were observed within the first decade following RA diagnosis.

Ankylosing Spondylitis, Psoriatic Arthritis, and Risk of Malignant Lymphoma : A Cohort Study Based on Nationwide Prospectively Recorded Data From Sweden

Data on lymphoma risk in ankylosing spondylitis (AS) and psoriatic arthritis (PsA) are scarce. This study was undertaken to assess the risk of lymphoma in AS and PsA overall and in relation to therapies, including tumor necrosis factor inhibitor (TNFi), for which lymphoma risks are a concern.

Rheumatoid arthritis, treatment with corticosteroids and risk of malignant lymphomas: results from a case–control study

Background Benefits and risks of corticosteroid treatment in rheumatoid arthritis (RA) are debated. Patients with RA are at increased risk of malignant lymphomas. In a large case–control study of risk factors for lymphoma in RA, it was recently reported that steroid treatment was associated with decreased lymphoma risk. Objective To further assess the nature of the association between steroid treatment in RA and the risk of lymphoma. Methods In a cohort of 74 651 patients with RA, 378 patients with lymphoma and 378 matched RA controls were identified, and information on inflammatory activity and different aspects of steroid treatment (duration, therapeutic strategy and mode of administration) abstracted from their medical records. Lymphomas were reclassified (WHO classification) and examined for Epstein–Barr virus. Relative risks were assessed as adjusted odds ratios (ORs) through conditional logistic regression. Results A total duration of oral steroid treatment of <2 years was not associated with lymphoma risk (OR=0.87; 95% CI 0.51 to 1.5), whereas total treatment >2 years was associated with a lower lymphoma risk (OR=0.43; 95% CI 0.26 to 0.72). RA duration at the initiation of oral steroids did not affect lymphoma risk. Intra-articular steroids were associated with a reduced lymphoma risk, but only when used as swift flare treatment (OR=0.22; 95% CI 0.13 to 0.37). Analyses by lymphoma subtype showed a reduced risk of diffuse large B-cell lymphoma (crude OR=0.59; 95% CI 0.37 to 0.94). Conclusion In this RA population, use of steroids was associated with reduced lymphoma risk. Whether this association is a generic effect of steroids or specific to the studied population remains unknown.

Cancer risk in patients with spondyloarthritis treated with TNF inhibitors: a collaborative study from the ARTIS and DANBIO registers

Background Safety data on cancer risks following tumour necrosis factor α inhibitors (TNFi) in patients with spondyloarthritis (SpA) (here defined as ankylosing spondylitis (AS), undifferentiated spondarthropaties (SpA UNS), psoriatic arthritis (PsA)) are scarce. Our objective was to assess risks for cancer overall and for common subtypes in patients with SpA treated with TNFi compared with TNFi-naïve patients with SpA and to the general population. Methods From the Swedish (Anti-Rheumatic Therapy in Sweden (ARTIS)) and Danish (DANBIO) biologics registers, we assembled 8703 (ARTIS=5448, DANBIO=3255) patients with SpA initiating a first TNFi 2001–2011. From the Swedish National Patient and Population Registers we assembled a TNFi-naïve SpA cohort (n=28,164) and a Swedish age-matched and sex-matched general population comparator cohort (n=131 687). We identified incident cancers by linkage with the nationwide Swedish and Danish Cancer Registers 2001–2011, and calculated age-standardised and sex-standardised incidence ratios as measures of relative risk (RR). Results Based on 1188 cancers among the TNFi-naïve patients with SpA, RR of cancer overall was 1.1 (95% CI 1.0 to 1.2). Based on 147 cancers among TNFi initiators with SpA, RR versus TNFi-naïve was 0.8 (95% CI 0.7 to 1.0) and results were similar for AS and PsA when analysed separately. Site-specific cancer RRs: prostate 0.5 (95% CI 0.3 to 0.8), lung 0.6 (95% CI 0.3 to 1.3), colorectal 1.0 (95% CI 0.5 to 2.0), breast 1.3 (95% CI 0.9 to 2.0), lymphoma 0.8 (95% CI 0.4 to 1.8) and melanoma 1.4 (95% CI 0.7 to 2.6). Conclusions In patients with SpA, treatment with TNFi was not associated with increased risks of cancer, neither overall nor for the six most common cancer types.

Low Risk of Birth Defects for Infants Whose Mothers Are Treated With Anti–Tumor Necrosis Factor Agents During Pregnancy

BACKGROUND & AIMS Safety data on anti-tumor necrosis factor (anti-TNF) treatment during pregnancy are limited. We studied the risk of birth defects after anti-TNF treatment in early pregnancy. METHODS We collected data on 1,272,424 live-born infants identified from the Danish (2004-2012) and Swedish (2006-2012) population-based health registers. We determined the prevalence of birth defects among infants born to women with chronic inflammatory disease (inflammatory bowel disease, rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, or psoriasis), with (n = 683) and without (n = 21,549) anti-TNF treatment during early pregnancy, and in the general population. We compared the risk of any major birth defect and birth defect by organ system for infants born to women with chronic inflammatory disease, with and without anti-TNF treatment. Risks were presented as odds ratios (ORs) with 95% confidence intervals (CIs). We adjusted for maternal age, parity, smoking, body mass index, multiple gestation, country, and chronic inflammatory diagnosis. RESULTS Birth defects were more prevalent among infants born to women with chronic inflammatory disease, regardless of anti-TNF treatment status, than in the general population (4.8% vs 4.2%). Birth defects occurred in 43 of the infants born to the 683 women who received anti-TNF treatment (6.3%), and 1019 of the infants born to women with chronic inflammatory disease (4.7%). The OR for any defect in women receiving anti-TNF therapy was 1.32 (95% CI, 0.93-1.82); the OR for a cardiovascular defect was 1.60 (95% CI, 0.93-2.58), and the OR for a urinary defect was 2.22 (95% CI, 0.86-4.71). CONCLUSIONS Based on an analysis of data from the health registries in Denmark and Sweden, women who received anti-TNF agents during pregnancy had a slightly (but not significantly) higher risk of having children with birth defects. Although larger studies are needed, the heterogeneity of the observed birth defects did not indicate a common etiology.

Familial aggregation of arthritis-related diseases in seropositive and seronegative rheumatoid arthritis: a register-based case-control study in Sweden

Objectives Our objective was to estimate the risk of developing rheumatoid arthritis (RA) associated with a family history of non-RA arthritis-related diseases. This familial co-aggregation is of clinical interest since it is often encountered when assessing family history of RA specifically, but also informative on the genetic overlap between these diseases. Since anticitrullinated peptide antibodies/rheumatoid factor (RF)-positive and RF-negative RA have both specific and shared genetic factors, the familial co-aggregation was assessed separately for seropositive and seronegative disease. Methods Nested case-control study in prospectively recorded Swedish total population data. The Multi-Generation Register identified first-degree relatives. RA and arthritis-related diseases were ascertained through the nationwide patient register. RA serology was based on International Classification of Diseases tenth revision coded diagnoses, mainly reflecting RF. Familial risks were calculated using conditional logistic regression. Results were replicated using the Swedish rheumatology register. Results Familial co-aggregation was found between RA and every studied arthritis-related disease, but the magnitude varied widely, from juvenile idiopathic arthritis (JIA) (seropositive RA OR=3.98 (3.01 to 5.26); seronegative RA OR=5.70 (3.47 to 9.36)) to osteoarthritis (seropositive RA OR=1.03 (1.00 to 1.06); seronegative RA OR=1.05 (1.00 to 1.09)). The familial co-aggregation pattern of non-RA arthritis-related diseases was overall similar for seropositive and seronegative RA. Among those with family history of RA, relatives’ other arthritis-related diseases conferred little or no additional risk. Conclusions Although family history of several arthritis-related diseases may be useful to predict RA (eg, lupus and JIA), others (eg, osteoarthritis and arthralgia) are less useful. Seropositive and seronegative RA had rather similar familial co-aggregation patterns with arthritis-related diseases, suggesting that the two RA subsets are similar in the genetic factors that overlap with these diseases.

Rheumatoid Arthritis and Risk of Malignant Lymphoma: Is the Risk Still Increased?

Patients with rheumatoid arthritis (RA) are at increased risk of malignant lymphomas with a strong correlation with RA disease severity. Given the changes in RA therapy over recent decades, this study was undertaken to assess whether lymphoma risk remains increased, and if so, to explore risk predictors and lymphoma subtypes.

Fluconazole-induced intoxication with phenytoin in a patient with ultra-high activity of CYP2C9

PurposeThe cytochrome P450 enzyme CYP2C9 metabolizes several important drugs, such as warfarin and oral antidiabetic drugs. The enzyme is polymorphic, and all known alleles, for example, CYP2C9*2 and*3, give decreased activity. Ultra-high activity of the enzyme has not yet been reported.MethodsWe present a patient with Behçet’s disease who required treatment with high doses of phenytoin. When fluconazole, a potent inhibitor of CYP2C9, was added to the treatment regimen, the patient developed ataxia, tremor, fatigue, slurred speech and somnolence, indicating phenytoin intoxication. On suspicion of ultra-high activity of CYP2C9, a phenotyping test for CYP2C9 with losartan was performed.ResultsThe patient was shown to have a higher activity of CYP2C9 than any of the 190 healthy Swedish Caucasians used as controls.ConclusionsOur finding of an ultrarapid metabolism of losartan and phenytoin may apply to other CYP2C9 substrates, where inhibition of CYP2C9 may cause severe adverse drug reactions.

Spectrum of lymphomas across different drug treatment groups in rheumatoid arthritis: a European registries collaborative project

Background Lymphomas comprise a heterogeneous group of malignant diseases with highly variable prognosis. Rheumatoid arthritis (RA) is associated with a twofold increased risk of both Hodgkin’s lymphoma (HL) and non-Hodgkin’s lymphoma (NHL). It is unknown whether treatment with biologic disease-modifying antirheumatic drugs (bDMARDs) affect the risk of specific lymphoma subtypes. Methods Patients never exposed to (bionaïve) or ever treated with bDMARDs from 12 European biologic registers were followed prospectively for the occurrence of first ever histologically confirmed lymphoma. Patients were considered exposed to a bDMARD after having received the first dose. Lymphomas were attributed to the most recently received bDMARD. Results Among 124 997 patients (mean age 59 years; 73.7% female), 533 lymphomas were reported. Of these, 9.5% were HL, 83.8% B-cell NHL and 6.8% T-cell NHL. No cases of hepatosplenic T-cell lymphoma were observed. Diffuse large B-cell lymphoma (DLBCL) was the most frequent B-cell NHL subtype (55.8% of all B-cell NHLs). The subtype distributions were similar between bionaïve patients and those treated with tumour necrosis factor inhibitors (TNFi). For other bDMARDs, the numbers of cases were too small to draw any conclusions. Patients with RA developed more DLBCLs and less chronic lymphocytic leukaemia compared with the general population. Conclusion This large collaborative analysis of European registries has successfully collated subtype information on 533 lymphomas. While the subtype distribution differs between RA and the general population, there was no evidence of any modification of the distribution of lymphoma subtypes in patients with RA treated with TNFi compared with bionaïve patients.

Opportunities and challenges for real-world studies on chronic inflammatory joint diseases through data enrichment and collaboration between national registers: the Nordic example

There are increasing needs for detailed real-world data on rheumatic diseases and their treatments. Clinical register data are essential sources of information that can be enriched through linkage to additional data sources such as national health data registers. Detailed analyses call for international collaborative observational research to increase the number of patients and the statistical power. Such linkages and collaborations come with legal, logistic and methodological challenges. In collaboration between registers of inflammatory arthritides in Sweden, Denmark, Norway, Finland and Iceland, we plan to enrich, harmonise and standardise individual data repositories to investigate analytical approaches to multisource data, to assess the viability of different logistical approaches to data protection and sharing and to perform collaborative studies on treatment effectiveness, safety and health-economic outcomes. This narrative review summarises the needs and potentials and the challenges that remain to be overcome in order to enable large-scale international collaborative research based on clinical and other types of data.