[Correlation of lymphocytes and PIIINP with the combined pulmonary fibrosis and emphysema].

AIM: To approach the relationships among inflammation, immune response, and fibrosis in combined pulmonary fibrosis and emphysema (CPFE) through the observation of distributions of lymphocyte subtypes, the variation of Pro-collagen III N-terminal peptide (PIIINP) expression and the severity of pulmonary fibrosis (PF) in CPFE.

METHODS: From March 2005 to March 2007, 21 diagnosed cases of CPFE, 25 diagnosed cases of idiopathic pulmonary fibrosis (IPF) and 19 cases of controls were involved in the study from the First Affiliated Hospital of Xi'an Jiaotong University. The patients were subjected to the following investigations including pathological changes in lung tissue biopsy specimens by light microscopy, counting and classification of inflammatory cells out of bronchoalveolar lavage fluids (BALF), determination of T-lymphocyte subtypes by flow cytometry (FCM), and detection of PIIINP level in BALF and blood serum by radioimmunoassay.

RESULTS: The pathological data showed higher degree of fibrosis in IPF group than that in CPFE group (P<0.01), but the level of fibrosis in the two Zgroups had nothing to do with smoking status (P>0.05). The inflammatory cells and lymphocyte cells in BALF were more in CPFE group than those in IPF and control groups (P<0.05, P<0.01 respectively). The FCM showed CPFE group had more CD8+ T-lymphocytes than IPF and control groups (P<0.05), whereas CPFE and IPF groups showed significantly lower CD4+/CD8+ ratio than the control group (P<0.01). There was no significantly statistical difference in the percentage of CD4+ T-lymphocytes among the three groups (P>0.05). CPFE and IPF groups exhibited significantly higher level of blood PIIINP than the control group (P<0.01), while IPF group showed markedly higher level of blood PIIINP than CPFE group (P<0.01). BALF and blood level of PIIINP were positively correlated (gamma=0.82).

CONCLUSION: The pulmonary fibrosis in CPFE shows intrinsic characteristics, with smoking not being the major or direct PF-driven factor. The CPFE group showed significant inflammation predominated by T-lymphocytes, especially CD8+; T-lymphocyte, as compared with the IPF and control groups, hence pointing to the fact that a novel anti-lymphocytes and immune regulation strategy may be useful for disease intervention. Blood serum PIIINP may be used as a marker for early detection of CPFE and also as a monitor for efficacy of treatments.