Serum chitotriosidase activity in sarcoidosis patients

Excerpt

In the May 2007 issue, Brunner and colleagues [1] reported two cases of juvenile sarcoidosis with significantly elevated chitotriosidase activity. The authors measured chitotriosidase and angiotensin converting enzyme concentrations and erythrocyte sedimentation rate in serum at onset and at different times during clinical remission. They concluded that chitotriosidase may be a useful marker for monitoring sarcoidosis activity, adding that further studies were needed to validate their results. In their case report, Brunner et al. did not compare their results with those previously published by our research group which has been studying chitotriosidase as a marker of sarcoidosis in adults for several years [2‐5]. In 2004 we firstly found a statistically significant increase in chitotriosidase activity in serum of adult sarcoidosis patients with respect to controls; this increase was particularly evident in active phase [2]. Chitotriosidase (and not ACE) activity in serum turned out to be correlated with sarcoidosis radiographic stages, suggesting its potential as a prognostic marker of sarcoidosis [2, 3]. The quantification of chitotriosidase in BAL revealed that chitotriosidase was significantly increased in sarcoidosis than controls and its activity correlated positively with radiographic stage, serum levels of ACE and quantitative HRCT score, especially in patients with progressing sarcoidosis [3]. With these first studies we demonstrated that chitotriosidase could be considered a very sensitive marker of sarcoidosis, and recently we analysed enzyme specificity by comparing its concentrations in serum of 96 sarcoidosis patients and serum of patients with other granulomatous lung diseases (such as tuberculosis [4]) and interstitial lung diseases (including idiopathic pulmonary fibrosis and pulmonary fibrosis associated with systemic sclerosis [5]). We concluded that chitotriosidase was only elevated in sarcoidosis and not in other similar macrophage-mediated lung diseases. In conclusion, the observations of Brunner et al. [1] in their two patients with juvenile sarcoidosis confirmed our previous data in a large cohort of adult sarcoidosis patients. …