Peptide-antibody Fusions Engineered by Phage Display Exhibit Ultrapotent and Broad Neutralization of SARS-CoV-2 Variants

The COVID-19 pandemic has been exacerbated by the emergence of variants of concern (VoCs). Many VoC mutations are found in the viral spike protein (S-protein), and are thus implicated in host infection and response to therapeutics. Bivalent neutralizing antibodies (nAbs) targeting the S-protein receptor-binding domain (RBD) are promising therapeutics for COVID-19, but are limited due to low potency and vulnerability to RBD mutations found in VoCs. To address these issues, we used naive phage-displayed peptide libraries to isolate and optimize 16-residue peptides that bind to the RBD or the N-terminal domain (NTD) of the S-protein. We fused these peptides to the N-terminus of a moderate affinity nAb to generate tetravalent peptide-IgG fusions, and showed that both classes of peptides were able to improve affinities for the S-protein trimer by >100-fold (apparent KD <1 pM). Critically, cell-based infection assays with a panel of six SARS-CoV-2 variants demonstrate that an RBD-binding peptide was able to enhance the neutralization potency of a high-affinity nAb >100-fold. Moreover, this peptide-IgG was able to neutralize variants that were resistant to the same nAb in the bivalent IgG format. To show that this approach is general, we fused the same peptide to a clinically approved nAb drug, and showed that it rescued neutralization against a resistant variant. Taken together, these results establish minimal peptide fusions as a modular means to greatly enhance affinities, potencies, and breadth of coverage of nAbs as therapeutics for SARS-CoV-2.

Diagnostic and Predictive Utility of Serum Interleukin-37 in Rheumatoid Arthritis: A Case-Control Study

Background: Rheumatoid arthritis is the most common cause of inflammatory polyarthritis. Interleukin‐37 (IL-37) has been found to play an important regulatory role in the development of inflammatory diseases. Objectives: To assess serum IL-37 level in rheumatoid arthritis (RA) patients compared to controls, to evaluate its diagnostic and predictive utility in RA patients and to investigate IL-37 level correlation with demographic and clinical characteristics of RA. Methods: Eighty subjects, 40 RA patients aged between 23-63 years and 40 healthy controls aged between 28-67 years were evaluated. An enzyme-linked immunosorbent assay (ELISA) was used to analyze the serum IL-37 levels. Results: Serum IL-37 was significantly higher in RA patients compared to healthy controls. At optimum cut off value of >58.275 pg/ml, serum IL-37 had 100% accuracy, positive predictive value, negative predictive value, sensitivity, and specificity. Serum IL‐37 level was not significantly related to Disease Activity Score of 28 joints‐erythrocyte sedimentation rate (DAS28‐ESR), also not correlated with C-reactive protein(CRP), rheumatoid factor(RF) and anti-cyclic citrullinated peptide antibody (Anti-CCP). Also there was no correlation between the level of IL-37 and treatment. Conclusions: IL-37 was significantly higher in RA patients compared to healthy controls with a high diagnostic and predictive ability, and may be a potential biomarker for diagnosis and prediction of RA.

The Clinical Course of Rheumatoid Arthritis in Kazakhstani Patients

BACKGROUND: Rheumatoid arthritis (RA) prevalence according to the worldwide epidemiological data varies from 0.4% to 1.3%. The disability and mortality rate in RA is high. RA clinic is various, and compiles from articular and systemic manifestations. AIM: The aim of our study was to investigate the clinical course of RA in Kazakhstani patients living in North region of our country. METHODS: The 81 women at the age of 30–55 years with a verified diagnosis of RA who have lived in Kazakhstan for at least 10 years were recruited to the study. All participants were examined by the rheumatologist and a standard laboratory examination was carried out. Statistical analysis was conducted in IBM SPSS Statistics 26 software (IBM.USA;1). RESULTS: The statistically significant higher frequency of erosive radiological stages, bone ankylosis (χ2 = 18.070 df = 6 p = 0.005) was found in seropositive (rheumatoid factor [RF]+) anti-citrullinated protein/peptide antibody positive (ACPA+) subgroup. The correlation analysis showed strong association between certain RA form activity and inflammatory markers, as well as disease triggers. The discriminant model which predicts the stage of radiological damage was obtained. The sensitivity of model in predicting X-ray Stage I-71.6%, Stage II-29.4%, Stage III-37.5%, and Stage IV-63.6%. CONCLUSION: The debut of the RA on average occurred in the third decade of the patients’ life. The joint syndrome had a more unfavorable character RF+ACPA+ patients’ subgroup; however, RF+ACPA-negative (ACPA-) subgroup also showed a predisposition to poorer prognosis. The obtained discriminant model may be useful for RA patients’ management.

Salazosulfapyridine-induced agranulocytosis in a patient on chronic hemodialysis with seronegative spondyloarthropathy: a case report

Background Salazosulfapyridine is a generally safe drug often used to treat rheumatoid arthritis and ulcerative colitis. However, agranulocytosis is a rare but serious adverse effect of this drug. To date, there have been no reports describing the clinical course of salazosulfapyridine-induced agranulocytosis in a chronic hemodialysis patient. Case presentation The patient was a 64-year-old man with IgA nephropathy who had been on chronic hemodialysis for about 3 years. For 1 month, he had general fatigue, mild fever, and pain in multiple joints of the upper extremities. He was hospitalized and underwent detailed examinations in our department. Laboratory investigations revealed an erythrocyte sedimentation rate of 67 mm/h and a C-reactive protein level of 7.73 mg/dL. Rheumatoid factor and anti-cyclic citrullinated peptide antibody were negative. Musculoskeletal ultrasonography showed inflammation of the tendon sheath in both wrists and the right shoulder joint. Computed tomography scans revealed osteosclerosis and narrowing of the sacroiliac joint. The diagnosis was seronegative spondyloarthropathy. He was started on salazosulfapyridine. Four weeks later, he had a high fever and low granulocyte count. Treatment with granulocyte colony-stimulating factor was started. The agranulocytosis could not be ascribed to any other cause and was considered an adverse effect of salazosulfapyridine, which was then stopped. Nine days later, the granulocyte count had recovered and the fever had resolved. Conclusions Currently, there are no guidelines on the use of salazosulfapyridine in chronic hemodialysis patients. The starting dosage should be smaller for these patients than for patients without renal impairment. Also, the laboratory monitoring interval for complete blood count should be shorter than usual.

OTOİMMÜN ROMATOİD HASTALIKLARDA OTOANTİKORLAR

The diagnosis of autoimmune rheumatoid diseases can be made by combining parameters consisting of clinical, histopathological, laboratory and immunological tests. Among these parameters, autoantibodies are of great benefit in differential diagnosis, especially for patients with unclear clinical data. Immunofluorescence, ELISA, immunodiffusion, immunoprecipitation and Western blot can be used to identify autoantibodies. While autoantibodies like antinukleer antibody, double stranded deoksiribonukleic asid and anti neutrophils antibody are detected by immunofluorescence as a golden standard test, Anti-cyclic Citrullinated Peptide Antibody (CCP), antiphospholipid antibodies (anti-cardiolipid) are evaluated by ELISA and ENA group by immunoblot or western blot. Today the number of autoantibodies that can be detected is over 100. The indication of some of these autoantibodies are not known even today. The definition of antinuclear antibody group autoantibodies plays a crucial role for the diagnosis and treatment of systemic and organ-specific illnesses. With these methods, practical, fast and trustworthy results in clinical medicine and clinical immunology can be obtained.

Diagnostic value of anti-cyclic citrullinated peptide antibody combined with rheumatoid factor in rheumatoid arthritis in Asia: a meta-analysis

Objective This meta-analysis explored the diagnostic value of anti-cyclic citrullinated peptide antibody (anti-CCP) and rheumatoid factor (RF) for rheumatoid arthritis (RA) in the Asian population. Methods Embase, Medline, Cochrane Library, Chinese Science and Technology Periodicals, China National Knowledge Infrastructure, and China Wanfang Databases were searched from 1 January 2000 to 1 February 2021 to collect studies on the combined detection of anti-CCP and RF for diagnosing RA. The sensitivity, specificity, diagnostic odds ratio (DOR), positive likelihood ratio (+LR), and negative likelihood ratio (−LR) were combined and analyzed. Summary receiver operating characteristic (SROC) curves were drawn. Results Twenty-four published papers were analyzed, including 21 combined in series and 8 combined in parallel. In the tandem analysis, the sensitivity = 0.64 [95% confidence interval (CI): 0.58–0.70], specificity = 0.97 (95%CI: 0.95–0.98), +LR = 19.70 (95%CI: 12.74–30.46), −LR = 0.37 (95%CI: 0.31–0.43), DOR = 53.43 (95%CI: 34.46–82.40), and area under the SROC curve = 0.89. In the parallel combination, the sensitivity = 0.87 (95%CI: 0.80–0.92), specificity = 0.76 (95%CI: 0.67–0.84), +LR = 3.68 (95%CI: 2.62–5.17), −LR = 0.17 (95%CI: 0.11–0.26), DOR = 21.56 (95%CI: 11.63–39.99), and area under the SROC curve = 0.89. Conclusion Anti-CCP and RF combined detection improves the diagnostic efficiency of RA, providing a potential strategy for early clinical screening in the Asian population. This trial was retrospectively registered in the INPLASY/Research Registry ( https: //inplasy.com/ ) with the registration number INPLASY202180106.

Atrial Natriuretic Peptide Antibody-Functionalised, PEGylated Multiwalled Carbon Nanotubes for Targeted Ischemic Stroke Intervention

Stroke is one of the major causes of disability and the second major cause of death around the globe. There is a dire need for an ultrasensitive detection tool and an effective and efficient therapeutic system for both detection and treatment of stroke at its infancy stage. Carbon nanotubes are promising nanomaterials for tackling these challenges. The loading of dexamethasone and decoration of PEGylated multiwalled carbon nanotube with atrial natriuretic peptide (ANP) antibody and fluorescein isothiocyanate for targeting ischemic site in the rat stroke model is presented here. Functionalisation of carbon nanotubes with dexamethasone (DEX), polyethylene glycol (PEG), fluorescein isothiocyanate (FITC), and ANP antibody caused a 63-fold increase in the D band intensity as illustrated by Raman. The characteristic band intensity increase was observed at 1636 nm following functionalisation of carbon nanotubes with polyethylene glycol and dexamethasone as confirmed by Fourier Transform Infrared. These findings have demonstrated the coupling capability of atrial natriuretic peptide antibody to DEX-PEG-CNTs. The baseline plasma atrial natriuretic peptide levels were ranging from 118 to 135.70 pg/mL prior to surgery and from 522.09 to 552.37 following common carotid artery occlusion. A decrease in atrial natriuretic peptide levels to 307.77 was observed when the rats were treated with FITC-DEX-PEG-ANP-CNTs, PEG-CNTs and DEX with a significant drop in the FITC-DEX-PEG-ANP-CNTs treated group. Fluorescence was detected in FITC-DEX-PEG-CNTs and FITC-DEX-PEG-ANP-CNTs treated ischemic stroke rats. The highest fluorescence intensity was reported in plasma (2179) followed by the kidney (1563) and liver (1507). These findings suggest a beneficial role that is played by the FITC-DEX-PEG-ANP-CNTs in the reduction of inflammation in the ischemic stroke induced rats that could induce a successful treatment of ischemic stroke.