5.1. Procollagen I carboxyterminal propeptide and procollagen III aminoterminal propeptide in bronchoalveolar lavage fluid and serum of sarcoidosis and fibrosing alveolitis patients (I,II)

The levels of serum procollagen I carboxyterminal propeptide were similar in sarcoidosis, fibrosing alveolitis and the controls. Three sarcoidosis patients, one out of forty in the non-parenchymal and two out of twenty in the parenchymal sarcoidosis group, and none with fibrosing alveolitis had S-PICP over the upper normal limit of 200 µg/l. The levels of serum-PIIINP in the sarcoidosis and fibrosing alveolitis patients were similar and significantly higher than in the controls (Table 6). Eight sarcoidosis patients, five (12.5%) without parenchymal involvement and three (15%) with parenchymal changes, had elevated S-PIIINP compared to the normal upper limit of 4.5 µg/l. Four (22%) of the 18 fibrosing alveolitis patients had S-PIIINP above the normal upper limit. Two patients with fibrosing alveolitis had elevated S-ALAT values, suggesting the possibility of a hepatic lesion. These patients’ values were excluded, since hepatic disease might elevate S-PIIINP. None of the controls had S-PIIINP or S-PICP over the reference values.

The levels of BALF-PIIINP were significantly elevated in sarcoidosis and fibrosing alveolitis compared to the controls, and BALF-PIIINP was significantly higher in sarcoidosis than in fibrosing alveolitis (p<0.05, not shown). BALF-PIIINP was detectable in two (12%) of the 17 control subjects, in 22 (37%) of the 60 sarcoidosis patients, and in 9 (50%) of the 18 patients with fibrosing alveolitis. The concentration of PIIINP in ELF was higher in sarcoidosis than in fibrosing alveolitis (p<0.05) and higher in the latter group than in the controls (Table 6). In the sarcoidosis patients the average concentration of PIIINP in ELF was 121 times and in the fibrosing alveolitis patients 13 times higher than the corresponding serum level.

The level of procollagen I carboxyterminal propeptide in BALF was elevated in fibrosing alveolitis and sarcoidosis compared to the controls. It was highest in fibrosing alveolitis, although the difference compared to sarcoidosis was not statistically significant. BALF-PICP was detectable in 22 (39%) out of 57 sarcoidosis and 7 (39%) out of 18 fibrosing alveolitis patients, while it could not be detected in the controls. The concentration of PICP in ELF was highest in fibrosing alveolitis, followed by the levels recorded in sarcoidosis, whereas no PICP in ELF was detectable in the controls (Table 6). The average concentration of PICP was twofold in ELF compared to the serum concentration in sarcoidosis and fourfold in ELF compared to serum concentration in fibrosing alveolitis.