ObjectiveTo investigate whether antidrug antibodies and/or drug non‐trough levels predict the long‐term treatment response in a large cohort of patients with rheumatoid arthritis (RA) treated with adalimumab or etanercept and to identify factors influencing antidrug antibody and drug levels to optimize future treatment decisions.MethodsA total of 331 patients from an observational prospective cohort were selected (160 patients treated with adalimumab and 171 treated with etanercept). Antidrug antibody levels were measured by radioimmunoassay, and drug levels were measured by enzyme‐linked immunosorbent assay in 835 serial serum samples obtained 3, 6, and 12 months after initiation of therapy. The association between antidrug antibodies and drug non‐trough levels and the treatment response (change in the Disease Activity Score in 28 joints) was evaluated.ResultsAmong patients who completed 12 months of followup, antidrug antibodies were detected in 24.8% of those receiving adalimumab (31 of 125) and in none of those receiving etanercept. At 3 months, antidrug antibody formation and low adalimumab levels were significant predictors of no response according to the European League Against Rheumatism (EULAR) criteria at 12 months (area under the receiver operating characteristic curve 0.71 [95% confidence interval (95% CI) 0.57, 0.85]). Antidrug antibody–positive patients received lower median dosages of methotrexate compared with antidrug antibody–negative patients (15 mg/week versus 20 mg/week; P = 0.01) and had a longer disease duration (14.0 versus 7.7 years; P = 0.03). The adalimumab level was the best predictor of change in the DAS28 at 12 months, after adjustment for confounders (regression coefficient 0.060 [95% CI 0.015, 0.10], P = 0.009). Etanercept levels were associated with the EULAR response at 12 months (regression coefficient 0.088 [95% CI 0.019, 0.16], P = 0.012); however, this difference was not significant after adjustment. A body mass index of ≥30 kg/m2 and poor adherence were associated with lower drug levels.ConclusionPharmacologic testing in anti–tumor necrosis factor–treated patients is clinically useful even in the absence of trough levels. At 3 months, antidrug antibodies and low adalimumab levels are significant predictors of no response according to the EULAR criteria at 12 months.

Objective-To determine whether genetic factors associated with established rheumatoid arthritis could, in combination with rheumatoid factor, predict the development of radiological erosions in patients with early symmetrical (rheumatoid-like) arthritis.Design-Prospective study. Setting-Teaching hospital, early arthritis clinic.Subjects-Forty nine patients with symmetrical polyarthritis attending the early arthritis clinic.Main outcome measures-Conserved sequence of DR3 third allelic hypervariable region, sulphoxidation capacity, rheumatoid factor, and development ofradiologically determined bone erosions.Results-None of the 49 patients had radiological erosions at presentation but 25 developed these by four years. Patients with the conserved class II major histocompatibility complex (third allelic hypervariable of DR31) genes associated with rheumatoid arthritis had a relative risk for the development of erosions of 1-9 (950/o confidence interval 0-8 to 4 5). For poor sulphoxidation the risk was 2 5 (1.1 to 5.6) and for the presence of rheumatoid factor 1P8 (0.9 to 3.7). Ofthe 33 patients who had two or three of these risk factors, 24 developed erosions, with a relative risk of 116 (1.7 to 78.5) compared with only one of the 16 individuals with no or one risk factor.Conclusions-This preliminary study shows that by using these stable markers it is possible to make clinically useful predictions of outcome in patients with early symmetrical inflammatory arthritis.

Early rheumatoid arthritis (RA) must be differentiated from benign self-limiting polyarthritis because of the risks associated with treatment of RA. Conventional, widely available clinical and laboratory variables, measured at first clinic visit, were studied for their ability to predict persistence in 112 patients with up to 6 months of joint symptoms. Those 65 patients with symmetrical peripheral polyarthritis were followed for 1 year: 36 who underwent spontaneous remission were classified self-limiting synovitis (SLS); the remaining 29 were termed persistent synovitis (PS). Univariate analysis suggested more severe disease in PS at presentation but showing considerable overlap with SLS, making clinical discrimination difficult. Multivariate analysis confirmed this overlap but identified a subset of most helpful variables. The RA latex was the most powerful variable, yet accounted for only 45% of the variability in outcome. Combining a positive RA latex with an ESR > 30 mm/h carried a relative risk for PS of 4.33, with specificity 94% but sensitivity only 69%. Self-limiting synovitis initially could not be distinguished from early RA: hence RA may exist in two forms, the traditional persistent form and a less well recognized abortive form.

We studied combination therapy with two slow-acting antirheumatic drugs given concurrently in active rheumatoid arthritis (RA). A 12-month prospective randomized controlled trial compared gold and hydroxychloroquine in 52 patients to gold and placebo in 49. The patients continued to receive non-steroidal anti-inflammatory drugs and analgesics. They were selected from three rheumatology centres in the West Midlands. Combination therapy led to a greater number of withdrawals due to adverse reactions (18 cases compared to 10 receiving gold/placebo). Patients completing 12 months' therapy (27 taking gold/hydroxychloroquine and 32 on gold/placebo) were compared using five clinical, seven laboratory, and one radiological measure. All 13 variables favoured gold/hydroxychloroquine with an overall advantage of 20-25% for the combination. This only reached statistical significance (at the 1% level) for C-reactive protein. An overall disease activity index was better at 12 months (at the 5% level) and showed a more rapid response with gold/hydroxychloroquine. This is the first randomized prospective placebo-controlled trial to show a significant advantage from a combination of two slow-acting drugs. There are many different ways of giving such combinations and we consider these should be explored to maximize the effectiveness of treatment for RA.

This prospective study documents the haematological responses in 300 rheumatoid patients (RA) treated with sulphasalazine (SASP) for between 1 and 9 years. It also examines the effect of SASP on the total white cell and platelet counts over 2 years in relation to disease activity in 80 RA patients. Neutropenia occurred in six (2%) (three severe--neutrophil count less than 0.8 X 10(9)/l) after 3 and 12 weeks. The drug was withdrawn in six immediately and in one patient after 21 months when the neutrophil count fell to 0.7 X 10(9)/l. An additional 11 (3.7%) developed mild or transient leucopenia between 2 weeks and 24 months, and eight continued therapy. Thrombocytopenia occurred in one patient at 18 weeks associated with other reactions. Four with Felty's syndrome developed a further fall in the total WBC associated with thrombocytopenia in two. A rise in mean cell volume was common (72%), and macrocytosis (MCV greater than 98 fl) occurred in 27 (9%). Macrocytic anaemia was rare (less than 1%). All haematological problems were reversible. In 80 patients treated with SASP for 2 years there was a significant fall in the median white cell and platelet counts at 3 months associated with improvement in disease activity.

RA is associated with a group of class II DR beta alleles, which share a conserved sequence in the third allelic hypervariable region (3AHVR). These include the DR4 subtypes Dw4, Dw14 and Dw15, and also DR1. In contrast Dw10 and Dw13 which are also DR4 subtypes show no association with RA and have a quite distinct 3AHVR. We have assessed the frequency of these alleles in 55 patients who initially presented with symmetrical peripheral polyarthritis suggestive of RA. After 4 years 27 had progressed to definite or classical RA, while 28 had never fulfilled the criteria for this disease. Dw4 was markedly elevated in the rheumatoid group (17/23) compared with either the non-rheumatoids (5/28) or healthy controls (12/100). Dw14 and non-DR4 associated DR1 were not elevated in either group of patients. This study suggests that the DR beta association with RA is likely to facilitate persistence or severity of disease rather than the initial induction of symmetrical peripheral arthritis.

Abnormalities in serum immunoglobulin levels (Igs) are documented in a series of 350 patients with rheumatoid arthritis (RA) and other inflammatory joint diseases treated with sulphasalazine (SASP) for up to 10 years. Low Ig levels occurred in just over 10% of patients after therapy. Three per cent developed selective IgA deficiency between 8 and 20 weeks after starting SASP. Low IgG levels occurred in 2% at 4-52 weeks and low IgM levels in 5% after 3-7 months. One per cent developed panhypogammaglobulinaemia (hypo gamma) 3-7 months after commencing therapy. Most immunodeficiencies were not accompanied by other toxic reactions and SASP was continued in all but one patient with a rash and thrombocytopenia. A good clinical response was observed in most patients particularly those with selective IgA deficiency and hypo gamma. Two patients with hypo gamma developed chest infections which responded to antibiotics. A low level of individual Igs is not usually an indication to stop SASP unless accompanied by other reactions. Panhypo gamma is potentially serious and should be monitored carefully and replacement therapy should be considered in these patients if infections occur.

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