Objectives To evaluate the usefulness of a negative D-dimer in peripheral or central venous blood to screen for asymptomatic catheter-related thrombosis in cancer patients. Methods D-dimer was measured in blood from central venous catheter and peripheral venous samples in 48 patients with cancer. Asymptomatic catheter-related thrombosis was identified via Doppler ultrasound. Bland and Altman's limits of agreement analysis was used to compare sample sites. Sensitivity and specificity of D-dimer was calculated. Results Overall, 33 of the central samples and 32 of the peripheral samples had D-dimer levels below the cutoff (≥0.3 mg/l). Mean central D-dimer was 0.31 ± 0.35 mg/l; peripheral 0.24 ± 0.22 mg/l (p = 0.5). Bland-Altman plot showed that the two sample sites were not equivalent. Catheter-related thrombosis was demonstrated in five patients, and there were three false negatives. Peripheral D-dimer had a negative predictive value of 90.9%. Conclusions A negative D-dimer may be useful for screening asymptomatic catheter-related thrombosis in patients with cancer, but the central and peripheral sample sites are not equivalent.

Neutralizing antibodies (NAs) are key immunological markers and are part of the humoral response of the adaptive immune system. NA assays determine the presence of functional antibodies to prevent SARS-CoV-2 infection. We performed a real-world evidence study to detect NAs that confer protection against SARS-CoV-2 after the application of five vaccines (Pfizer/BioNTech, AstraZeneca, Sinovac, Moderna, and CanSino) in the Mexican population. Side effects of COVID-19 vaccines and clinical and demographic factors associated with low immunogenicity were also evaluated. A total of 242 SARS-CoV-2-vaccinated subjects were recruited. Pfizer/BioNTech and Moderna proved the highest percentage of inhibition in a mono-vaccine scheme. Muscular pain, headache, and fatigue were the most common adverse events. None of the patients reported severe adverse events. We found an estimated contagion-free time of 207 (IQR: 182–231) and 187 (IQR: 184–189) days for Pfizer/BioNTech and CanSino in 12 cases in each group. On the basis of our results, we consider that the emerging vaccination strategy in Mexico is effective and safe.

Familial adenomatous polyposis (FAP) is an autosomal-dominant condition characterized by the presence of multiple colorectal adenomas, caused by germline variants in the adenomatous polyposis coli (APC) gene. More than 300 germline variants have been characterized. The detection of novel variants is important to understand the mechanisms of pathophysiology. We identified a novel pathogenic germline variant using next-generation sequencing (NGS) in a proband patient. The variant is a complex rearrangement (c.422+1123_532-577 del ins 423-1933_423-1687 inv) that generates a complete deletion of exon 5 of the APC gene. To study the variant in other family members, we designed an endpoint PCR method followed by Sanger sequencing. The variant was identified in the proband patient’s mother, one daughter, her brother, two cousins, a niece, and a second nephew. In patients where the variant was identified, we found atypical clinical symptoms, including mandibular, ovarian, breast, pancreatic, and gastric cancer. Genetic counseling and cancer prevention strategies were provided for the family. According to the American College of Medical Genetics (ACMG) guidelines, this novel variant is considered a PVS1 variant (very strong evidence of pathogenicity), and it can be useful in association with clinical data for early surveillance and suitable treatment.