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Background and Objective: It is still controversial how to screen for interstitial lung disease (ILD) in patients with rheumatoid arthritis (RA). We aimed to evaluate the performance of lung ultrasound (LUS) as a screening tool for RA‐ILD and to compare it with the performance of chest auscultation, chest x‐ray and pulmonary function tests (PFTs). Methods: Cross‐sectional study of consecutive RA patients evaluated at a Rheumatology Clinic in Buenos Aires between January and December 2022. High‐resolution computed tomography (HRCT) was the gold standard for diagnosing ILD and was performed within 30 days of the LUS, chest x‐ray and PFTs. Investigators were blinded to HRCT results and patients' clinical data. LUS was performed by exploring 14 areas and was considered positive when the sum of B lines was ≥5. Performance for the diagnosis of ILD was reported for each diagnostic test. Results: One hundred and six patients were included; 87 (82%) were women. Median age was 60.9 (±9.5) years‐old. A total of 32 (30.2%, 95% CI: 21.6%–39.9%) had ILD. The sensitivity and negative predictive value of LUS were 90.6% (95% CI 75.0%–98.0%) and 94.7% (95% CI 85.4%–98.9%), respectively. LUS performance was superior to that of the other evaluated diagnostic tests for screening ILD. Conclusions: Given that the US is a low‐cost point‐of‐care tool with a high negative predictive value, it is emerging as a valuable tool for ruling out ILD in patients with RA. [ABSTRACT FROM AUTHOR]

The binding of sensitized red cells to Fc receptors in human monocytes was studied by evaluating the effects of various pharmacological reagents and other treatments on EA rosette formation. Cytochalasin B and 2-deoxyglucose inhibited rosette formation in a dose-dependent manner. Sodium azide and incubation at 4° also inhibited rosette formation, while at 37° increased numbers of RBCs bound to the monocytes. The microtubular poisons, vinblastine and colchicine at high concentrations resulted in decreased adherence of monocytes and inhibition of rosette formation, while at low concentrations of colchicine, enhanced rosette formation was sometimes observed. Contrary to the effects on rosette formation, binding of [125I] IgG to monocyte monolayers was not altered by treatment of the monocytes with drugs. Magnesium ions were required to promote monocyte adherence, but both magnesium and calcium were needed for the best rosette formation. We conclude that the formation of EA rosettes is dependent not merely on binding of IgG to the Fc receptor but requires metabolically active monocytes, an intact cytostructure and suitable environmental conditions (temperature and cation concentration). [ABSTRACT FROM AUTHOR]

Several laboratories, including our own, have previously shown !hat the B7 antigen, a glycoprotein expressed on activated B cells, macrophages and dendritic cells, can provide a potent costimulatory signal for peripheral marine T lymphocytes. In the present report we have analysed the expression and function of B7 in the marine thymus. The expression of B7 was demonstrated histochemically. B7-expressing cells were present in the thymic medulla but virtually absent from the cortex. Further analysis by immunofluorescence and flow fluorocytometry revealed that the B7-positive cells also expressed major histocompatibility complex (MHC) class II molecules. Both epithelial and dendritic cells expressed the B7 antigen. Finally, although we have demonstrated expression of mB7 in the marine thymus, we have been unable to detect a function for this antigen in this organ. The implications of these findings are discussed. [ABSTRACT FROM AUTHOR]

Human monocytes were maintained in tissue culture and the effect of various stimuli on their morphology and capacity to synthesize and secrete total protein, lysozyme, acid phosphatase, prostaglandin E and the second component of complement were determined. Human monomeric IgG, Fab fragments and albumin had no effect on the secretion of these products. However, addition of Fc fragments significantly decreased the synthesis of both lysosomal enzymes and the second component of complement and increased production of prostaglandin E. The addition of Con A to the monocyte monolayers resulted in a similar response. Latex particles slightly increased the secretion of acid phosphatase and C2, but had no effect on lysozyme secretion. Fc fragments also stimulated protein synthesis by monocyte monolayers cultured in serum-free medium. These ‘activators’ and endotoxin- or antigen-activated mononuclear cell supernatants (AMNS) resulted in varying degrees of increased spreading and adherence of the monocytes. The results of these studies suggest that the molecular species inducing the ‘activated state’ qualitatively and quantitatively determines the characteristics of the secretory response. [ABSTRACT FROM AUTHOR]