Incidence of amyloidosis over 3 years: the AMYPRO study

There is a lack of epidemiological information concerning amyloidosis, particularly in France. We started a 3-year prospective study (AMPYRO) to analyze the epidemiological features of amyloidosis in the eastern part of France.

From 2003 to 2005, all patients with a tissue sample showing amyloid deposits, were included in this study. Immunohistochemistry using anti-P component, anti-SAA, anti-light chains immunoglobulins and anti-transthyretin was applied for each tissue sample. For each patient, past and present medical histories along with biological features were recorded.

Seventy-six patients with amyloid were identified over 3 years. The age-standardized incidence rate of amyloidosis was estimated at 14 cases per million person-years. The final entire population included in the AMYPRO study was composed of 66 patients with a mean age of 71.7+/-11.5 years old. The amyloid typing after clinical, biological and immunohistochemistry revealed senile amyloid in 40 cases (60.6%), AL amyloid in 13 (19.7%) and AA amyloid in 9 (13.6%). Neither clinical nor biological features differed significantly between the transthyretin-positive and transthyretin-negative populations.

Regarding only tissue samples, senile amyloid was the most prominent amyloid type identified. Therefore, the clinician needs to be aware that in most of the amyloid cases identified on the pathologic examination there is no need for additional examination unless there are clinical or biological signs of a primary or secondary amyloidosis.