Site-Selective Protein Conjugation by a Multicomponent Ugi Reaction.

The chemical bioconjugation of proteins has seen tremendous applications in the past decades, with the booming of antibody-drug conjugates and their use in oncology. While genetic engineering has permitted to produce bespoke proteins featuring key (un-)natural amino acid residues poised for site-selective modifications, the conjugation of native proteins is riddled with selectivity issues. Chemoselective strategies are plentiful and enable the precise modification of virtually any residue with a reactive side-chain; site-selective methods are less common and usually most effective on small and medium-sized proteins. In this context, we studied the application of the Ugi multicomponent reaction for the site-selective conjugation of amine and carboxylate groups on proteins, and antibodies in particular. Through an in-depth mechanistic methodology work supported by peptide mapping studies, we managed to develop a set of conditions allowing the highly selective modification of antibodies bearing N-terminal glutamate and aspartate residues. We demonstrated that this strategy did not alter their affinity toward their target antigen and produced an antibody-drug conjugate with subnanomolar potency. Excitingly, we showed that the high site selectivity of our strategy was maintained on other protein formats, especially on anticalins, for which directed mutagenesis helped to highlight the key importance of a single lysine residue.

Screening for pulmonary arterial hypertension in patients with systemic sclerosis in the era of new pulmonary arterial hypertension definitions.

OBJECTIVES: This study compares the performance of three composite pulmonary arterial hypertension (PAH) screening tools in a real-life SSc cohort, according to both the previous 2015 ESC/ERS guideline and the recent 2022 ESC/ERS guideline haemodynamic criteria. METHODS: Consecutive SSc patients without a previous diagnosis of pulmonary hypertension (PH) were screened for PAH using the European Society of Cardiology/European Respiratory Society (ESC/ERS), DETECT, and Australian Scleroderma Interest Group (ASIG) algorithms. Right heart catheterisation (RHC) referral performances for PAH were compared according to the 2022 ESC/ERS PAH criteria. RESULTS: Thirty-five of the 81 patients required RHC; 15 (18.5%) according to ESC/ERS, 27 (33.3%) according to DETECT, and 25 (31%) according to ASIG. The final diagnoses were no-PH in 17 patients, WHO group 1 PH (PAH) in 8 patients, WHO group 2 PH in 8 patients, and WHO group 3 PH in 2 patients. When the hemodynamic criteria of the previous ESC/ERS guideline were applied, only one patient was diagnosed with PAH. The sensitivities of the algorithms for the diagnosis of PAH were 62.5% for ESC/ERS, 75% for DETECT, 87.5% for ASIG according to the 2022 ESC/ERS guideline definition, and 100% for all according to the previous ESC/ERS guideline. CONCLUSIONS: With the recent criteria, PAH diagnosis in patients with SSc increased by 1.8-fold. Current algorithms for screening PAH are less sensitive with these revised criteria. Although the ASIG algorithm seems more sensitive, it can still miss the diagnosis. The multimodal/algorithmic approach seems to be the best option for predicting PAH.

Psychiatric comorbidity and quality of life in patients with drug hypersensitivity.

Background: Compared with advances in a drug hypersensitivity diagnosis and management, little is known about the mental health status of patients with drug hypersensitivity and the impact of this psychological distress on their quality of life (QoL). Objective: The objectives were to evaluate anxiety, depression, and QoL levels in patients with drug hypersensitivity, assess how some related factors may affect them, and determine the impact of disease on their QoL. Methods: A total of 203 patients with drug hypersensitivity and 80 healthy controls were evaluated with the Beck Anxiety (BAI) and the Depression Inventory (BDI), and the short version of the World Health Organization Quality of Life (WHOQOL-BREF) scale. Results: The mean ± standard deviation (SD) BAI scores of the patients and the controls were 13.46 ± 11.78 and 1.94 ± 1.93, respectively (p < 0.0001). The mean ± SD BDI scores were higher in the patient group (9.23 ± 6.36) than in the control group (2.18 ± 2.02) (p < 0.0001). The patients had significantly increased risk of anxiety versus the controls (48.8% versus 7.5%) (odds ratio [OR] 11.74 [95% confidence {CI}, 4.88-28.20]; p < 0.0001) and depression versus the controls (31.5% versus 6.2%) (OR 6.90 [95% CI, 2.66-17.90]; p = 0.0001). The comparison of patients' BAI and BDI scores showed that those with more severe reactions had higher scores than those with moderate and mild reactions. A negative correlation was found among all WHOQOL-BREF scale domain scores and the BAI and BDI scores. Conclusion: Anxiety and depressive symptoms have a high prevalence in patients with confirmed drug hypersensitivity, which leads to a notable decrease in QoL. Self-administered psychological questionnaires were shown to be useful in the psychological examination and management of patients with drug hypersensitivity. Therefore, we found that psychological support is critical to reducing the negative outcomes of hypersensitivity reactions in patients.

Inactive SARS-CoV-2 vaccine generates high antibody responses in healthcare workers with and without prior infection.

BACKGROUND AND OBJECTIVES: Healthcare workers (HCWs) were among the first groups to be vaccinated in Turkey. The data to be obtained by the vaccination of HCWs would guide wide spread vaccination programs. MATERIALS AND METHODS: The study included 330 HCWs working at Istanbul University-Cerrahpasa, Cerrahpasa Medical Faculty Hospital and vaccinated with inactive CoronaVac (Sinovac Life Sciences, China) SARS-CoV-2 vaccine in two doses (28 days apart). Anti-Spike /RBD IgG levels were measured 14 days after the first dose and 28 days after the second dose. Chemiluminescent microparticle immunoassay (CMIA) (ARCHITECT IgG II Quant test, Abbott, USA), which is 100% compatible with plaque reduction neutralization test (PRNT), was used. RESULTS: Of the participants, 211 (63.9%) were female, 119 (36.1%) were male, and mean age was 39.6 ± 7.7 years. In those without prior COVID-19 history; (n = 255) antibody positivity was detected as 48.2% (95% CI: 42.1-54.3) 14 days after the first dose of vaccine, and 99.2% (95% CI: 98.1-100) at day 28 after the second dose. Antibody titers were significantly lower in patients with hypertension (p = 0.011). In those with prior history of COVID-19 (n = 75); both the antibody positivity rates after the first vaccine (48.2% vs 100%, p = 0.000) and the anti-spike/RBD antibody levels after the second vaccine (with a ≥ 1050 AU/mL titer equivalent to PRNT 1/80 dilution) was significant than infection-naive group (25.9% vs. 54.7%, p = 0.000). Antibody positivity after two doses of vaccination for all study group was 99.4% (95% CI: 98.6-100). CONCLUSIONS: Two doses CoronaVac produce effective humoral immunity in HCWs. Antibody response is significantly higher in those with prior history of COVID-19 than infection-naive group. Given no significant benefit of the second dose, a single shot of vaccination may be sufficient for those with prior history of COVID-19. Monitoring humoral and cellular immune responses, considering new variants, is required to validate this approach.