Biomarker collection from the Caribbean Hispanic families from Dominican Republic and New York

Background Genetic Studies of Alzheimer’s Disease in Caribbean Hispanics (CH) has been ongoing for over 20 years. Our primary goal was to identify genes in large well‐phenotyped, multiplex families, and sporadic cases and controls. This longitudinal collection of data represents a unique resource for the scientific community. The project is led by collaborators in the United States (US) and the Dominican Republic (DR). For the past three years, our efforts have been centered on the collection of cerebrospinal fluid (CSF), plasma, serum and Paxgene tubes for RNA to study core biomarkers. Collection of blood samples for DNA to conduct genetic analyses is also ongoing. Method The cohort consisted of participants aged 50 and older from the DR, including those living in the New York City area, willing and able to provide a blood and CSF samples. Interviewers in the DR were trained to collect data, blood samples and CSF. DNA samples were sent overnight to Columbia university (CU) for processing. CSF, Paxgene tubes, serum and plasma samples were processed in the DR and stored at ‐80F for batch shipping to CU. APOE genotyping was conducted in the US. Biomarkers, metabolomics, and proteomics data was generated at Columbia University. Methylation assays from Paxgene was conducted at Uniformed Services University (USUHS). Result We have databased a total of 1899 individuals with plasma samples, 1707 with Paxgene, 1731 with serum and 203 with CSF. Blood samples from 1079 participants have genome wide arra, whole genome sequencing and APOE genotyping. 192 CSF samples have proteomics completed, 153 CSF samples have metabolomics data and 742 have plasma biomarkers (Ab40, Ab42, T‐tau, P‐tau181, NFL and GFAP)). Conclusion Sample collection for genetic studies in developing countries present important logistical challenges. Despite these challenges, sample quality is comparable to those collected in New York. Biomarkers from CSF, serum and plasma can give us a closer look into underrepresented populations such as Caribbean Hispanics. Results suggest that similar protocols can be successful in Latin America. Future work will augment the biosample collection of the cohort by collecting samples from additional subjects.