Prevalence of chronic idiopathic neutropenia of adults among an apparently healthy population living on the island of Crete.

The aim of the present study was to investigate the prevalence of chronic idiopathic neutropenia of adults (CINA) among an apparently healthy population born and living on the island of Crete. The study was carried out with 778 subjects, 392 men aged 16-78 years (median 43 years) and 386 women aged 15-79 years (median 40 years). All were employees of the Medical School or the adjacent University hospital and members of their families. Among these there were 64 subjects (8.23%) who fulfilled the diagnostic criteria of CINA applied in our department. Mild neutropenia (neutrophils 1700-2499/microl) accounted for 6.81% and moderate neutropenia (neutrophils 600-1699/microl) for the remaining 1.41%. No cases of CINA with severe neutropenia (neutrophils below 600/microl) were found. CINA was more frequent in women, with a women to men ratio of about 3:2. Approximately two thirds of the cases appeared in patients aged 30-59 years. Concomitant thrombocytopenia was found in three of the 64 subjects with CINA. Neutropenic subjects had chronic (perennial) rhinitis 3.4 times more frequently than non-neutropenics. No influence of occupation, use of insecticides and pesticides, contact with industrial chemicals, or administration of nonsteroidal anti-inflammatory drugs on the development of CINA was documented. We conclude that, despite the biased character of the study (population not randomly selected), our data provide a valuable estimation of the prevalence of CINA in the general population, given that our sample was sufficiently large, was derived from all major regions of the island, and was composed of subjects of both genders and of all age-groups from 15 to 79 years.