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.

Adult GH deficiency (AGHD) is associated with reduced bone mineral density, and decreased end-organ sensitivity to the effects of PTH has been suggested as a possible underlying mechanism. We investigated the effects of GH replacement (GHR) on PTH circulating activity and its association with phosphocalcium metabolism and bone turnover in 16 (8 men and 8 women) AGHD patients. Half-hourly blood and 3 hourly urine sampling was performed on each patient over a 24-h period before GHR and then after 1, 3, 6, and 12 months of GHR. GH was commenced at a dose of 0.5 IU/d and was titrated to achieve and maintain an IGF-I SD score within 2 SD of the age-related reference range. The target IGF-I SD score was achieved within 3 months and was maintained at 12 months after GHR in all patients. Our results demonstrated a significant decrease in serum PTH at all visits after GHR compared with baseline values (P < 0.001), with a concomitant increase in nephrogenous cAMP excretion at 1 (P < 0.001) and 3 (P < 0.05) months and increases in serum calcium (P < 0.001), serum phosphate (P < 0.001), 1,25-dihydroxyvitamin D(3) (P < 0.001), type I collagen C-telopeptide (a bone resorption marker; P < 0.001), and procollagen type I amino-terminal propeptide (a bone formation marker; P < 0.001). Simultaneously, we observed a significant decrease in urinary calcium excretion (P < 0.001) and an increase in maximum tubular phosphate reabsorption (P < 0.001). Together these results suggest increased end-organ responsiveness to the effects of circulating PTH resulting in increased bone turnover and reduced calcium excretion. Significant circadian rhythms were observed for serum PTH, phosphate, type I collagen C-telopeptide, and procollagen type I amino-terminal propeptide before and after GHR. However, sustained PTH secretion was observed between 1400-2200 h, with a reduced nocturnal rise in untreated AGHD patients, whereas PTH secretion decreased significantly between 1400-2200 h (P < 0.001), with a significant increase in nocturnal PTH secretion (P < 0.001) after 12 months of GHR. Our results demonstrate that GH may have a regulatory role in bone mineral metabolism, and our data provide a possible underlying mechanism for the development of osteoporosis in AGHD patients. The changes observed after GHR may further explain the beneficial effects of GHR on bone mineral density that have consistently been reported.

A 62-year-old man presented with bilateral diffuse uveal melanocytic proliferations (BDUMP) and painful flexor contractures of the fingers of both hands. All these features were considered paraneoplastic but extensive and repeated investigations revealed no underlying malignancy. Oral steroids and orbital radiotherapy were ineffective. The diagnosis was confirmed by trans-scleral biopsy of the right choroid. Rapidly progressive cataracts were treated by phacoemulsification. Severe exudative retinal detachment with rubeosis and neovascular glaucoma in the left eye were treated successfully by partial choroidectomy. Fifteen months after presentation, investigations detected a 22 mm, poorly differentiated adenocarcinoma, which was resected without complication. The ocular tumours in both eyes regressed, without improvement in vision of Light Perception, and the palmar fasciitis also improved. The patient remained free of tumour recurrence until sudden death from myocardial infarction five years after he first presented.

BACKGROUND Adult GH deficiency (AGHD) is associated with osteoporosis and reduced bone turnover;factors improved by GH replacement (GHR), with men gaining greater benefit than women. Reduction in sensitivity of bone and kidney to the effects of PTH may underlie AGHD changes in bone turnover. We determined the gender difference in PTH target-organ sensitivity following GHR in AGHD patients. DESIGN , PATIENTS AND MEASUREMENTS Twenty AGHD patients (10 men) were admitted to hospital before and after GHR initiation. Half-hourly blood samples were collected for PTH, calcium, nephrogenous cyclic AMP (NcAMP, marker of PTH activity), type-I collagen C-telopeptide (CTX, bone resorption marker) and procollagen type-I amino-terminal propeptide (PINP, bone formation marker). RESULTS The 24-h mean PTH concentration decreased in both genders ( P < 0·001), with maximal changes seen 6 and 12 months following GHR in men and women, respectively. Increases in 24-h mean NcAMP ( P < 0·05), calcium ( P < 0·001) and bone turnover markers ( P < 0·001) occurred in both genders following GHR, with maximal changes at 1 month in men, but at 3 months for NcAMP, calcium and CTX and 12 months for PINP in women. Maximal NcAMP increase was higher in men ( P = 0·009). CONCLUSIONS Following GHR, PTH target-organ sensitivity increased in both genders, demonstratedby simultaneous reduction in PTH concentration and increase in NcAMP, calcium and bone turnover. In women, improvement in renal PTH sensitivity was delayed and reduced, and changes in bone turnover were delayed, with increase in bone resorption preceding bone formation. Both factors may contribute to the reduced bone mineral density (BMD) response to GHR observed in women.

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