Assessment of two screening tools to identify psoriatic arthritis in patients with psoriasis.

BACKGROUND: Many patients with psoriasis have undiagnosed psoriatic arthritis. Low specificity is found with many PsA screening tools. A new instrument, the CONTEST questionnaire, was developed utilizing the most discriminative items from existing instruments. OBJECTIVE: The aim of this study was to compare the CONTEST and PEST screening tools. METHODS: People attending secondary care clinics with psoriasis, but not PsA, completed the questionnaires, were assessed for function and quality of life, and had a physical examination. Patients thought to have PsA were compared to those without. The performance of CONTEST and PEST was compared using area under the receiver operating curve (AUC), and sensitivity and specificity at the previously published cut-offs. RESULTS: A total of 451 dermatology patients were approached, 35% were reviewed and 27 (17%, 95% CI 12.3-21.7) had unidentified psoriatic arthritis. The sensitivity and specificity (95% CI) of PEST were 0.60 (0.42-0.78)/0.76 (0.69-0.83) and for CONTEST 0.53 (0.34-0.72)/0.71 (0.63-0.79). The confidence limits for the AUC overlapped (AUC for PEST 0.72 (0.61-0.84), for CONTEST 0.66 (0.54-0.77). CONCLUSIONS: PEST and CONTEST questionnaires performed equally well, with no superiority of the new CONTEST tool.

The pea chloroplast membrane-associated protein, IEP96, is a subunit of acetyl-CoA carboxylase.

Two forms of acetyl-CoA carboxylase (ACCase) have been characterized in pea (Pisum sativum L.) leaves; a heteromeric chloroplast enzyme and a homomeric, presumably cytosolic enzyme. The biotin carboxylase (BC), biotin carboxyl carrier protein (BCCP), and beta-carboxyltransferase (CT) subunits of the plastidial-ACCase have recently been characterized and cloned. To further characterize the carboxyltransferase, an improved assay for CT was developed and used to follow its partial purification. CT activity co-purifies with ACCase activity during gel permeation chromatography. However, upon anion-exchange chromatography or native PAGE, CT separates from the BC and BCCP subunits of plastidial-ACCase and ACCase activity is lost. In addition, it is demonstrated that a previously sequenced pea chloroplast cDNA of unknown function (IEP96) with a predicted molecular weight of 91 kDa encodes the alpha-CT subunit of the MS-ACCase. Antibodies raised against the first 404 amino acids of IEP96 protein detected a polypeptide with molecular weight of 91 kDa that co-eluted during gel permeation chromatography with plastidial CT and ACCase activities. These antibodies also immunoprecipitated the activities of both ACCase and CT with the concomitant precipitation of the beta-CT subunit. Furthermore, antibodies against beta-CT immunoprecipitated the IEP96 protein. Two-dimensional PAGE and DEAE purification of ACCase protein demonstrated that the beta-CT forms a tight association with the IEP96 protein. Pea leaf was fractionated into soluble and membrane fractions and the alpha-CT subunit was primarily associated with the membrane fraction. Together, these data demonstrate that IEP96 is the alpha-CT subunit of pea chloroplast ACCase.