Incidence rate of amyloidosis in patients from a medical care program in Buenos Aires, Argentina: a prospective cohort.

Background: There are limited data concerning the incidence density (ID) of ATTRwt, AL and AA amyloidosis in the Argentinean population. Our aim was to estimate the ID of ATTRwt, AL and AA amyloidosis at the Hospital Italiano Medical Care Program in Buenos Aires, Argentina.
Methods: Population was all members of a hospital-based health maintenance organization who were affiliated since January 2006 to December 2014. Each person was followed contributing time at risk since January 2006 or enrollment date to the final date. Incident cases of amyloidosis were captured from the institutional registry of amyloidosis. Incidence rate was calculated with 95% confidence intervals.
Results: During the nine-year study period, there were 15 patients with ATTRwt, 12 with AL and 2 with AA amyloidosis for 1 105 152 person-years of follow-up. The crude ID of ATTRwt amyloidosis was 13.5 (95%CI 8.1-22.4), that of AL amyloidosis 11 (95%CI: 6-19) and that of AA amyloidosis 1.8 (95%CI: 0.5-7.2) per 1 000 000 person-years. The highest ID was found in men (31.7 for ATTRwt, 15.9 for AL and 2.27 for AA amyloidosis per 1 000 000 person-years). The ID adjusted to the population of the city of Buenos Aires was 6.46 (95%CI: 3.17-9.74) for ATTRwt, 6.13 (95%CI: 2.57-9.7) for AL and 1.21 (95%CI: 0.56 to 2.99) for AA amyloidosis.
Conclusions: This is the first paper to report the incidence density of ATTRwt, AL and AA amyloidosis in Latin America. Our results are consistent with other studies from other regions. Although systemic amyloidosis is a rare disease, it is a major health problem because of its morbi-mortality.