mRNA-1273 SARS-CoV-2 vaccine in recently transplanted allogeneic hematopoietic cell transplant recipients: Dynamics of cellular and humoral immune responses and booster effect.

Allogeneic hematopoietic stem cell transplant (HCT) recipients are at high risk of severe COVID-19 despite vaccination. Little is known about cellular response to SARS-CoV-2 vaccine in this population, especially in recently transplanted patients (RTP). In this single-center study we examined cellular and humoral response to the mRNA-1273 (Spikevax®) vaccine in recently transplanted patients (RTP, n = 49), and compared them to long-term transplanted patients (LTTP, n = 19) and healthy controls (n = 20) at three different timepoints: one and three months after the second dose (T1 and T2, respectively, 28 days apart), and one month after the third dose (T3). Controls did not receive a third dose. RTPs showed lower IgG anti-S1 titers than healthy controls at both T1 (mean 0.50 vs 0.94 arbitrary units -AU-, p < 0.0001) and T2 (0.37 vs 0.79 AU, p < 0.0001). They also presented lower titers than LTTPs at T1 (0.50 vs 0.66, p = 0.01), but no differences at T2 (0.37 vs 0.40 AU, p = 0.55). The rate of positive T-cell responses was lower in RTPs than in controls at both T1 and T2 (61.2 % vs 95 %, p = 0.007; 59.2 % vs 100 %, p = 0.001, respectively), but without statistically significant differences between transplanted groups. At T3 no differences were seen between RTPs and LTTPs as well, neither in IgG antibodies (p = 0.82) nor in cellular responses (p = 0.15), although a third dose increased the rate of positive cellular and humoral responses in approximately 50 % of recently transplanted patients. However, active immunosuppressive treatment severely diminished their chances to produce an adequate response.

Parasitemia and Differential Tissue Tropism in Mice Infected with Trypanosoma cruzi Isolates Obtained from Meccus phyllosoma in the State of Oaxaca, Mexico.

Trypanosoma cruzi is a parasite transmitted by the feces of triatomines. Many triatomine species are found in Mexico, and various T. cruzi variants have been isolated from these species, each showing very different virulence and cell tropism. The isolates were obtained from Meccus phyllosoma specimens in three localities in the state of Oaxaca, Mexico: Tehuantitla, Vixhana, and Guichivere. The virulence of each isolate was assessed by quantifying parasitemia, survival, and histopathologic findings. The lineage of each isolate was identified using the mini-exon gene. The expression of the tssa gene during infection was detected in the heart, esophagus, gastrocnemius, and brain. Our results show that the maximum post-infection parasitemia was higher for the Tehuantitla isolate. On genotyping, all isolates were identified as T. cruzi I. The amastigotes in the heart and gastrocnemius were verified for all isolates, but in the brain only for Tehuantitla and Vixhana. The tssa expression allowed us to detect T. cruzi isolates, for Tehuantitla, predominantly in the heart. For Vixhana, a higher tssa expression was detected in gastrocnemius, and for Guichivere, it was higher in the esophagus. Results show that virulence, tropism, and tssa expression can vary, even when the isolates are derived from the same vector species, in the same region, and at similar altitudes.

mRNA-1273 SARS-CoV-2 vaccine safety and COVID-19 risk perception in recently transplanted allogeneic hematopoietic stem cell transplant recipients.

PURPOSE: This study aims to describe the incidence and severity of adverse events (AEs) following the mRNA-1273 SARS-CoV-2 vaccine and explore the risk perception of COVID-19 in allogeneic hematopoietic stem cell transplant (HCT) recipients. METHODS: We performed a single-center prospective study including recently transplanted (< 2 years post-infusion) allogeneic HCT recipients. AEs were assessed through phone calls and graded from 0 to 4, while COVID-19 risk perception was measured using the Brief Illness Perception Questionnaire (BIP-Q5). RESULTS: Fifty-four HCT recipients were evaluated. Incidence and grades of AE (94.4% and 85.2% after the first and second dose, respectively) were similar to those described in the general population. The most common AE was pain at the site of injection. Three patients (5.6%) developed a grade ≥ 3 AE. Vaccine-related cytopenias and graft-versus-host disease flares were not observed. Female sex (OR 3.94, 95% CI 1.14-13.58, p = 0.03) and time since HCT (per month since HCT: OR 1.09, 95% CI 1.01-1.18, p = 0.04) were associated with the occurrence of any AE. The patients' risk perception level of COVID-19 decreased over time (p < 0.05). CONCLUSION: Our study confirms that the mRNA-1273 SARS-CoV-2 vaccine is safe in recent HCT recipients and suggests that the perceived risk of COVID-19 decreases over time.

Efectos del tratamiento sustitutivo del hipotiroidismo subclínico en el grosor intima-media carotideo / Effects of replacement therapy for subclinical hypothyroidism on carotid intima-media thick

Introducción: El hipotiroidismo subclínico se relaciona con alteraciones cardiovasculares como la aterosclerosis carotidea subclínica por daños endoteliales como consecuencia de varios factores siendo el grosor intima-media carotideo (GIMC) un marcador reconocido, cuya elevación se menciona con frecuencia asociada a esta disfunción tiroidea. Objetivo: Determinar los efectos del tratamiento sustitutivo de pacientes con hipotiroidismo subclínico en el GIMC. Métodos: Se realizó un estudio de intervención que incluyó 94 pacientes con diagnóstico de hipotiroidismo subclínico sin tratamiento sustitutivo, que acudieron a la consulta de Endocrinología del hospital 10 de octubre a los cuales se les realizó determinación de TSH, colesterol total, colesterol LDL, colesterol HDL, triglicéridos y se les realizó US carotideo al inicio del estudio y al año de logrado el estado eutiroideo con tratamiento sustitutivo, para establecer diferencias en los parámetros evaluados antes y después del tratamiento sustitutivo. Resultados: Previo al tratamiento se encontró hipercolesterolemia en el 87,2 por ciento de los pacientes e hipertrigliceridemia en y 38,3 por ciento, mientras que, que valores elevados de colesterol LDL y disminuidos de colesterol HDL fueron hallados en el 55,3 por ciento y 19,3 por ciento de los mismos, el GIMC se mostró dentro del rango de normalidad. Tras el tratamiento con levotiroxina todos los valores medios de los parámetros estudiados se modificaron excepto en el caso de los triglicéridos Conclusiones: El tratamiento sustitutivo del hipotiroidismo subclínico tiene efectos beneficiosos sobre el GIMC, lo que pudiera ser secundario, entre otros factores, a la mejoría del perfil lipídico(AU)

Introduction: Subclinical hypothyroidism is related to cardiovascular alterations such as subclinical carotid atherosclerosis due to endothelial damage as a consequence of various factors, carotid intima-media thickness (CIMT) being a recognized marker, whose elevation is frequently mentioned in association with this thyroid dysfunction. Objective: To determine the effects of replacement therapy in patients with subclinical hypothyroidism in CIMT. Methods: An intervention study was carried out in 94 patients diagnosed with subclinical hypothyroidism, who did not have substitutive treatment. They were treated in Endocrinology consultation at 10 de Octubre hospital. These subjects underwent determination of TSH, total cholesterol, LDL cholesterol, cholesterol HDL, triglycerides. They got carotid ultrasound at the beginning of the study and one year after achieving euthyroid status with replacement treatment, to establish differences in the parameters evaluated before and after replacement treatment. Results: Prior to treatment, hypercholesterolemia was found in 87.2 percent of patients and hypertriglyceridemia in 38.3 percent, while elevated LDL cholesterol and decreased HDL cholesterol values were found in 55.3 percent and 19. .3 percent of them, CIMT was within the normal range. After treatment with levothyroxine, all the mean values of the parameters studied were modified, except in the case of triglycerides. Conclusions: Subclinical hypothyroidism replacement therapy has beneficial effects on CIMT, which could be secondary, among other factors, to the improvement of the lipid profile(AU)