Association between the Platelet-Derived Growth Factor/Platelet-Derived Growth Factor Receptor System and Risk of Rheumatoid Arthritis: A Systematic Review and Meta-Analysis

This research examines the association between the platelet-derived growth factor/platelet-derived growth factor receptor (PDGF/PDGFR) system and rheumatoid arthritis (RA) susceptibility through a comprehensive search of the PubMed database to study the expression of the PDGF/PDGFR system in RA. Review Manager software version 5.3 was used for statistical analysis. Six eligible studies published in the English language were included, including 108 rheumatoid arthritis cases and 85 controls with the corresponding 126 and 97 tests, respectively, relating the expression of the PDGF/PDGFR system to the risk of RA. The overall results indicated a significant association between the PDGF/PDGFR system expression and RA (OR = 5.25, 95% CI: 3.00-9.18, p < 00001), RA patients in Asian countries (OR = 4.13, 95% CI = 2.04-8.39, p < 0.0001) and in Western countries (OR = 9.18, 95% CI = 2.04-8.39, p = 0.03), and only PDGF expression in RA patients (OR = 5.28, 95% CI = 2.73-10.21, p < 0.00001). Thus, only the PDGFR expression was insignificantly associated with RA susceptibility (OR = 9.25, 95% CI = 0.63-136.30, p = 0.11). Hence, the PDGF/PDGFR system most likely contributes to susceptibility to RA.

Novel case of a scleroderma-mimicking syndrome associated with gastrointestinal stromal tumour

We report a case of a 54-year-old man who developed an atypical systemic syndrome involving Raynaud’s phenomenon, pulmonary fibrosis and skin thickening. These features were initially suggestive of newly diagnosed scleroderma. However, he displayed atypical clinical features of same, antinuclear antibody was negative and symptoms were refractory to various immunosuppressive therapies. CT imaging revealed a gastric mass, which later proved to be a gastrointestinal stromal tumour (GIST). Resection of the GIST leads to minimal symptomatic improvement. Surveillance imaging 1 year later revealed metastatic deposits. He was subsequently initiated on imatinib therapy, which led to a rapid improvement in fibrotic changes within weeks. While there have been previous descriptions of paraneoplastic fibrotic disorders, this is the first description of a scleroderma mimic in the setting of a GIST. It highlights an important potential overlap in the pathogenesis of these disease processes and the potential efficacy of tyrosine kinase inhibitors for scleroderma-like fibrotic disorders.

Vogt-Koyanagi-Harada patients show higher frequencies of circulating NKG2Dpos NK and NK T cells

Vogt-Koyanagi-Harada (VKH) is an autoimmune disease characterized by inflammation in tissues that contain melanocytes. We aimed to increase the knowledge regarding immunological pathways deregulated in VKH disease. We compared the percentages of circulating natural killer (NK), NK T and T cells expressing the activatory markers: CD16, CD69, NK group 2D (NKG2D), natural cytotoxicity triggering receptor 3 (Nkp30), natural cytotoxicity triggering receptor 1 (Nkp46) and the inhibitory marker: NK group 2 member A (NKG2A) in 10 active VKH patients, 20 control subjects (CTR) and seven patients with Behçet disease (BD) by flow cytometry. Cytotoxic potential of NK cells was determined through the degranulation marker CD107a expression after contact with K562 cells by flow cytometry. Moreover, plasmatic levels of 27 cytokines were determined with a multiplex bead-based assay. VKH patients showed higher percentages of NKG2D^pos NK and NK T cells versus CTR. The cytotoxic potential of NK cells induced by K562 cells was comparable between VKH patients and CTR. Finally, higher concentrations of interleukin (IL)-4, IL-5, IL-7, IL-17 and platelet-derived growth factor-subunits B (PDGF-bb) were detected in plasma of VKH patients versus CTR. The immune profile of VKH patients was similar to that of BD patients.

A biolayer interferometry-based enzyme-linked aptamer sorbent assay for real-time and highly sensitive detection of PDGF-BB

Accurate, fast and sensitive detection of disease-specific protein biomarkers, especially in blood, urine, or other bodily fluids, is an important approach to achieve early disease diagnosis. Platelet-derived growth factor-BB (PDGF-BB), a widely used biomarker, is involved in a substantial number of serious diseases, such as hepatic fibrosis, atherosclerosis, age-related macular degeneration and diabetic eye disease and is often over-expressed in human malignant tumors. Therefore, the development of sensitive and specific detection methods for PDGF-BB is of great importance for the early diagnosis of disease and assessments of patient recovery. In the current study, a biolayer interferometry-based enzyme-linked aptamer sorbent assay (BLI-ELASA) was successfully established for rapid (20-25min), high-throughput (8 or 16 samples) and real-time monitoring of PDGF-BB in clinical samples. The method exhibited a broad detection range from 0.5 to 1000ng/mL of PDGF-BB (good linear range from 0.5 to 10ng/mL), with a low detection limit of 0.08ng/mL. Moreover, BLI-ELASA was applied to the detection of PDGF-BB in spiked serum and urine samples and showed a high degree of selectivity for PDGF-BB, good reproducibility, and stability. We believe that the methodology in this work can be easily adapted to detect other biomolecules in clinical samples, including viruses, pathogens and toxins, in a rapid, sensitive, high-throughput and real-time manner.