Efficacy and Safety of Heterologous Booster Vaccination after Ad5-nCoV (CanSino Biologics) Vaccine: A Preliminary Descriptive Study

Several studies have reported the benefits and safety of heterologous vaccination among different approved vaccines; however, there are no specific reports on the effects of vaccination with the Ad5-nCoV and other vaccines of the same or different technologies. In the present study, we evaluated the neutralizing antibodies percentage against SARS-CoV-2 in Mexican patients immunized with the Ad5-nCoV vaccine six months after its application. Moreover, the effect of the heterologous vaccination with the Ad5-nCoV vaccine and a booster dose of ChAdOx1-S-Nov-19, Ad26.COV2.S, BNT162b2, or mRNA-127 were determined. Our results suggest that a heterologous regimen of one dose with Ad5-nCoV vaccine followed by a booster dose of a different vaccine is safe and induces a stronger humoral immune response

KIR/HLA Gene Profile Implication in Systemic Sclerosis Patients from Mexico

Introduction. Systemic Sclerosis (SSc) is an autoimmune, inflammatory, and multisystemic disease characterized by the presence of autoantibodies and fibrosis. The pathogenesis involves the interaction between immune system cells such as macrophages, NK cells, T cells, and B cells. Killer-cell Immunoglobulin-like Receptors (KIR) are expressed in NK cells and some T cell subsets that recognize HLA class I molecules as ligands and are involved in regulating the activation and inhibition of these cells. The KIR family consists of 14 genes and two pseudogenes; according to the gene content, the genotype could be AA and Bx. The aim of this study was to evaluate the association between KIR/HLA genes and genotypes with SSc and the clinical characteristics. Methods. We included 50 SSc patients and 90 Control Subjects (CS). Genotyping of KIR, HLA-C, -Bw4, and -A∗03/∗11 was made by SSP-PCR. Results. In SSc patients, a higher frequency of KIR2DL2 (p=0.0007, p′=0.011), KIR2DS4del (p=0.001, p′=0.021), and HLA-C2 (p=0.02, p′=0.09) was found. This is the first study to evaluate the frequency of HLA-A∗03/∗11 in SSc patients, of which a low frequency was found in both groups. Compound genotypes KIR2DL2+/HLA-C1+ or KIR2DL2+/HLA-C2+ have a higher frequency in SSc patients. The Bx genotype was the most frequent and was associated with risk to SSc (p=0.007, OR=3.1, 95% CI=1.4–7.9, p′=0.014). The genotypes with a higher iKIR number than aKIR (iKIR>aKIR) were found in all individuals; genotypes with 7-8 iKIR genes were increased in SSc patients. We do not find an association between the KIR genes with the clinical characteristics. Conclusion. The results suggest that KIR2DL2 and 2DS4del could have a risk role in the development of SSc, but not with clinical manifestations

<i>PADI4</i> Haplotypes Contribute to mRNA Expression, the Enzymatic Activity of Peptidyl Arginine Deaminase and Rheumatoid Arthritis Risk in Patients from Western Mexico

Citrullination is catalyzed by the peptidyl arginine deiminase 4 (PAD4) enzyme, encoded by the PADI4 gene. Increased PAD4 activity promotes the onset and progression of rheumatoid arthritis (RA). This study aimed to evaluate the association of PADI4 haplotypes with RA risk, mRNA expression, and the PAD4 activity in patients with RA from Mexico. Methodology: 100 RA patients and 100 control subjects (CS) were included. Genotyping was performed by PCR-RFLP method, PADI4 mRNA expression was quantified by real-time PCR, the contribution of PADI4 alleles (PADI4_89 G>A, PADI4_90 T>C, and PADI4_92 G>C) to mRNA expression by the ASTQ method, and PAD4 activity by HPLC. Also, the anti-CCP and anti-PADI4 antibodies were quantified by ELISA. Results: The three PADI4 polymorphisms were associated with RA susceptibility (OR = 1.72, p = 0.005; OR = 1.62; p = 0.014; OR = 1.69; p = 0.009; respectively). The 89G, 90T, and 92G alleles have a higher relative contribution to PADI4 mRNA expression from RA patients than 89A, 90C, and 92C alleles in RA patients. Moreover, the GTG/GTG haplotype was associated with RA susceptibility (OR = 2.86; p = 0.024). The GTG haplotype was associated with higher PADI4 mRNA expression (p = 0.04) and higher PAD4 enzymatic activity (p = 0.007) in RA patients. Conclusions: The evaluated polymorphisms contribute to PADI4 mRNA expression and the enzymatic activity of PAD4 in leukocytes. Therefore, the GTG haplotype is a genetic risk factor for RA in western Mexico, and is associated with increased PADI4 mRNA expression and higher PAD4 activity in these patients

<i>STAT4</i> Gene Variant <i>rs7574865</i> Is Associated with Rheumatoid Arthritis Activity and Anti-CCP Levels in the Western but Not in the Southern Population of Mexico

Rheumatoid Arthritis (RA) is a multifactorial autoimmune disease. Currently, several genes play an important role in the development of the disease. The objective was to evaluate the association of the STAT4 rs7574865 and rs897200 gene variants with RA susceptibility, DAS28, RF, and anti-CCP in Western and Southern Mexico populations. Genotyping was performed on 476 samples (cases = 240; controls = 236) using the Taqman® system and qPCR probes. Disease activity was assessed using DAS28 and HAQ DI. CRP, ESR, RF, and anti-CCP were determined for clinical assessment. Our study showed there is a statistically significant association with susceptibility to RA for the rs7574865 variant in the Western population for the GT and TT genotypes. The same genotypes also showed a moderate-to-high activity according to DAS28 and positive anti-CCP compared to the control group. This association was not found in the Southern population. This work confirms the association of the rs7574865 variant with RA, as well as a moderate-to-high activity and positive anti-CCP in the Western population but not in the Southern population. No association of the rs897200 variant was found in any of the studied populations