We previously reported that the – 2518 MCP-1 genotype GG increases the likelihood of developing tuberculosis (TB) in non-BCG-vaccinated Mexicans and Koreans. Here, we tested the hypothesis that this genotype, alone or together with the – 1607 MMP-1 functional polymorphism, increases the likelihood of developing TB in BCG-vaccinated individuals. We conducted population-based case-control studies of BCG-vaccinated individuals in Mexico and Peru that included 193 TB cases and 243 healthy tuberculin-positive controls from Mexico and 701 TB cases and 796 controls from Peru. We also performed immunohistochemistry (IHC) analysis of lymph nodes from carriers of relevant two-locus genotypes and in vitro studies to determine how these variants may operate to increase the risk of developing active disease. We report that a joint effect between the – 2518 MCP-1 genotype GG and the – 1607 MMP-1 genotype 2G/2G consistently increases the odds of developing TB 3.59-fold in Mexicans and 3.9-fold in Peruvians. IHC analysis of lymph nodes indicated that carriers of the two-locus genotype MCP-1 GG MMP-1 2G/2G express the highest levels of both MCP-1 and MMP-1. Carriers of these susceptibility genotypes might be at increased risk of developing TB because they produce high levels of MCP-1, which enhances the induction of MMP-1 production by M. tuberculosis-sonicate antigens to higher levels than in carriers of the other two-locus MCP-1 MMP-1 genotypes studied. This notion was supported by in vitro experiments and luciferase based promoter activity assay. MMP-1 may destabilize granuloma formation and promote tissue damage and disease progression early in the infection. Our findings may foster the development of new and personalized therapeutic approaches targeting MCP-1 and/or MMP-1.

Information on the effects of a heterologous booster in adult patients first vaccinated with the BBIBP-CorV vaccine is limited. This prospective cohort study evaluated the humoral response of 152 healthcare workers (HCWs) from a private laboratory in Lima (Peru) before and after receiving the BNT162b2 vaccine, with a seven-month interval since the BBIBP-CorV doses. We employed the Elecsys® anti-SARS-CoV-2 S and the cPass™ SARS-CoV-2 Neutralization Antibody (NAbs) assays to evaluate anti-S-RBD IgG and NAbs, respectively. Of the 152 HCWs, 79 (51.98%) were previously infected (PI) with SARS-CoV-2 and 73 (48.02%) were not previously infected (NPI). The proportion of HCWs with positive NAbs, seven months after the BBIBP-CorV immunization, was 49.31% in NPI and 92.40% in PI. After the booster, this ratio increased to 100% in both groups. The anti-S-RBD IgG and NAbs in the HCWs’ NPI increased by 32.7 and 3.95 times more, respectively. In HCWs’ PI, this increment was 5 and 1.42 times more, respectively. There was no statistical association between the history of previous SARS-CoV-2 infection and the titer of anti-S-RBD IgG and NAbs after the booster. The humoral immunity presented a robust increase after receiving the BNT162b2 booster and was more pronounced in NPI.

Insufficient data have been reported about the effect of the inactivated SARS-CoV-2 vaccine (BBIBP-CorV) on the humoral response through time in healthcare workers (HCW). This retrospective cohort studied the information of 252 HCW from a private laboratory, comparing the antibody-mediated response provoked by BBIBP-CorV between HCW previously infected with SARS-CoV-2 (PI) and not previously infected (NPI), employing the Elecsys® anti-SARS-CoV-2 S and the cPass™ SARS-CoV-2 Neutralization Antibody Detection kit at intervals of 21, 90, and 180 days after vaccination. The presence of neutralizing antibodies in HCW 21 days after full vaccination was 100% in PI and 91.60% in NPI. We observed a progressive decrease in antibody levels over time in both groups. Comparing HCW PI with NPI, PI had a 10.9, 14.3, and 8.6-fold higher antibody titer with the Elecsys® anti-SARS-CoV-2 S at 21 (p < 0.001), 90 (p< 0.001) and 180 days (p < 0.001) respectively, compared to NPI. Using the percent of signal inhibition (PSI) of the antibody neutralization cPass™, HCW PI showed a level of 1.3, 2.0, and 3.1 times more antibodies, at 21 (p < 0.001), 90 (p < 0.001), and 180 days (p < 0.001) respectively, compared to NPI. We determined a progressive decrease in humoral immunity over time, particularly higher in those NPI.

e13076 Background: The evaluation of EGFR mutational status of the EGFR in non-small cell lung cancer (NSCLC) is crucial to select the adequate targeted therapy and to know the outcome of patients. Previous studies in relative small sample sizes have described a higher prevalence of EGFR mutations in Peruvian population than other Latin American countries. Our aim in this study was to determine the prevalence of activating and resistance mutations of EGFR in a large cohort of Peruvian patients. Methods: We profiled metastatic tumor samples from 847 NSCLC patients for known EGFR mutations associated to sensitivity or resistance EGFR inhibitors, including exon 18 (G719X), exon 19 (deletions), exon 20 (T790M, S768I and insertions) and exon 21 (L858R). All samples were centrally tested in reference laboratory (Roe laboratory, Lima-Peru). Results: A total of 847 samples were profiled for EGFR mutational status. EGFR mutations were present in 32.9% of cases (n = 279). In regard to distribution of mutations in cases EGFR mutated, G719X (in exon 18) was present in 2.5% (n = 7); deletions in exon 19 had a frequency of 58.4% (n = 163). Mutations in exon 20 were present in 9.7% (n = 27). In patients with exon 20 mutated, 14 cases had insertions, 9 cases had the mutation T790M and 4 cases had the mutation S768I. Mutation L858R (exon 21) was present in 34.1% (n = 95) of cases. Coexistence of two mutations were present in exon 18/exon 20 (n = 1), exon 19/exon 20 (n = 7) and exon 20/ exon 21 (n = 5). In tumors with EGFR mutated. The sensible profile for EGFR tyrosine kinase inhibitors (TKI´s) was present in 96.8% of cases (n = 138). Conclusions: We have a high prevalence of EGFR mutations compared than Caucasian or other Hispanic cohorts. It has relevance in the Peruvian public health because more efforts should be done to screen NSCLC patients for EGFR mutations.

Cases of cryptococcosis have been reported in patients with COVID-19. The majority are in patients with severe symptoms or who received immunosuppressants. However, there is still no clear association between COVID-19 and cryptococcosis. We report eight cases of cerebral cryptococcosis associated with CD4+ T lymphocytopenia in non-HIV patients after SARS-CoV-2 infection. The median age was 57 years and 5/8 were male. In addition, 2/8 of patients had diabetes, and 8/8 had a history of mild COVID-19, with a median of 75 days before diagnosis of cerebral cryptococcosis. All patients denied having received prior immunosuppressive therapy. The most frequent symptoms were confusion (8/8), headache (7/8), vomiting (6/8), and nausea (6/8) All patients were diagnosed by isolating Cryptococcus in cerebrospinal fluid. The median CD4+ and CD8+ T lymphocytes were 247 and 173.5, respectively. Other causes of immunosuppression, such as HIV or HTLV infection, were excluded in all patients. Finally, three patients died, and one presented long-term visual and auditory sequelae. The CD4+/CD8+ T lymphocyte count normalized during follow-up in those patients who survived. We hypothesize that CD4+ T lymphocytopenia in the patients in this case series could increase the risk of cryptococcosis after SARS-CoV-2 infection.