Sarcoidosis and tuberculosis in South Croatia: are there epidemiological similarities or not?

Tuberculosis and sarcoidosis are chronic granulomatous diseases. Clinical, pathologic and immunologic aspects are similar although different. The authors were interested to highlight possible epidemiological similarities of these two granulomatous diseases. The objective of this study was to evaluate incidence rate as well as age, sex and geographic distribution of sarcoidosis in South Croatia and to compare it with these epidemiological characteristics of tuberculosis.

Retrospective.

The study was including ten years follow up period (1997-2006), and was performed in Split-Dalmatia County, Croatia. All data were collected retrospectively and analyzed using Statistica 7 programme.

The mean annual incidence of sarcoidosis was 3.3/100,000 inhabitants with a mean of 15,6 cases per year. Woman accounted for 61% of all sarcoidosis cases. The mean sarcoidosis patient age was 44.94 ± 11.85 years. The peak age group was 40-49 years (31%). Significant difference according to incidence rate on the islands comparing to the rates on the coast and the mainland was observed (P = 0.003). The mean sarcoidosis mortality rate was 1.2/100,000. Statistically significant differences between sarcoidosis and tuberculosis were observed according the higher number of tuberculosis patients (P < 0.000), among males (P < 0.000), and females, too (P < 0.000) as well as in mortality rates (P = 0.401). Significantly more patients had tuberculosis on the mainland (P < 0.000) and on the coast (P < 0.000), but not in the islands (P = 0.260).

The results from this study showed dissimilarities in classic epidemiological patterns between sarcoidosis and tuberculosis, incidence rates, as well as sex and geographic distribution. Our findings resulted from this study might be starting point for the future epidemiological, genetic, and immunological studies.