EPIDEMIOLOGICAL PERSPECTIVES OF AL AMYLOIDOSIS IN ARGENTINA: RESULTS OF AN ANALYSIS OF INCIDENCE AND MORTALITY IN A POPULATION AFFILIATED WITH A MEDICAL CARE PROGRAM

MARIA LOURDES POSADAS MARTINEZ; ET AL

Congreso; Reunión Conjunta SAIC-SAB-AAFE-AACYTAL 2023; 2023

EPIDEMIOLOGICAL PERSPECTIVES OF AL AMYLOIDOSIS IN ARGENTINA: RESULTS OF AN ANALYSIS OF INCIDENCE AND MORTALITY IN A POPULATION AFFILIATED WITH A MEDICAL CARE PROGRAMAutores: María Lourdes Posadas Martínez1, Delfina Cirelli1, Florencia De Florio2, Jimena Vicens2, María Adela Aguirre3, Elsa Mercedes Nucifora4, Valeria Inés Aliperti2, Marcelina Carretero1.1Internal Medicine Research Area, Internal Medicine Department, Hospital Italiano de Buenos Aires 2Epidemiology Section, Internal Medicine Department, Hospital Italiano de Buenos Aires 3 Internal Medicine Department, Hospital Italiano de Buenos Aires 4Hematology Section, Internal Medicine Department, Hospital Italiano de Buenos Aires Agradecimientos: a todo el Grupo de Estudio de Amiloidosis, en especial: Eugenia Villanueva, Diego Pérez de Arenaza, Erika Bárbara Brulc, María Soledad Sáez, Patricia Beatriz SorrocheObjective: Estimate the incidence and mortality rates of systemic AL amyloidosis in individuals affiliated with a Medical Care Program (MCP) in Buenos Aires, Argentina. Methods: The study included MCP-affiliated patients at the Italian Hospital of Buenos Aires from January 2011 to December 2022. Participants were followed since AL amyloidosis diagnosis, death, loss to follow-up, program withdrawal, or study closure. Incident AL amyloidosis cases and deaths were recorded from the Institutional Amyloidosis Registry. Incidence and mortality rates were calculated for the entire study period (2011-2022) and by four-year intervals (2011-2014, 2015-2018, 2019-2022) with corresponding 95% confidence intervals (95%CI). Crude, age-standardized, and stratified rates by age and sex were determined. Results: The crude incidence rate of AL amyloidosis was 16 (95%CI 11-24) cases per million persons/year. Incidence remained stable throughout the study [2011-2014= 13 (95%CI 6-28); 2015-2018= 14 (95%CI 7-29); 2019-2022= 20 (95%CI 11-36)], with an IRR of 0.7 (95% CI 0.2-1.8) when comparing the first and last four-year intervals. The age-standardized incidence rate compared to the US population was 6 (95%CI 4-9) cases per million persons/year. Regarding mortality, the crude rate was 11 (95%CI 7-17) cases per million persons/year. No significant sex differences were found, except in the age group over 80 years, where mortality was higher in men (IRR: 4.6, 95%CI 2-12). Additionally, mortality increased over time [2011-2014= 4 (95%CI 1-15); 2015-2018= 11 (95%CI 5-24); 2019-2022= 17 (95%CI 9-31)], with an IRR of 0.2 (95%CI 0.02-1). Conclusion: This study provides detailed information on the incidence and mortality of AL amyloidosis in a specific population, confirming its rarity. The observed increase in mortality rates over the study period could be partly attributed to a survival bias, where variations in disease severity and the timing of diagnosis may have influenced the results. These findings underscore the need for further epidemiological research to better understand the disease.