Open Access Highly Accessed Research article

Serum complement C4b, fibronectin, and prolidase are associated with the pathological changes of pulmonary tuberculosis

Chong Wang1, Yan-Yuan Li2, Xiang Li3, Li-Liang Wei4, Xiu-Yun Yang5, Dan-Dan Xu1, Ting-Ting Jiang1, Zhong-Jie Li1, Zhong-Liang Chen1, Xing Zhang1, Ji-Yan Liu1, Ze-Peng Ping1 and Ji-Cheng Li1*

Author Affiliations

1 Institute of Cell Biology, Zhejiang University, Hangzhou 310058, P.R. China

2 Department of Pathology, First Affiliated Hospital, Zhejiang University, Hangzhou 310003, P.R. China

3 Key Laboratory of Gastroenteropathy, Zhejiang Province People’s Hospital, Hangzhou 310012, P.R. China

4 The Sixth Hospital of Shaoxing, Shaoxing 312000, P.R. China

5 Department of Respiratory Medicine, Tongde Hospital of Zhejiang Province, Hangzhou 310012, P.R. China

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BMC Infectious Diseases 2014, 14:52  doi:10.1186/1471-2334-14-52

Published: 31 January 2014



Mycobacterium tuberculosis infection can activate the immune system, leading to characteristic pathological changes such as inflammatory granuloma, caseous necrosis, and cavity formation.


Clinical data of 187 cases of pulmonary tuberculosis (PTB) were analyzed using statistical methods, while serum levels of complement C4b (C4b), fibronectin (FN), and prolidase (PEPD) were detected using the ELISA method among the control, minimal PTB, moderate PTB, and advanced PTB groups.


We found significantly higher levels of serum C4b and PEPD (P = 0.018, P = 0.003), and significantly lower levels of serum FN (P < 0.001) in PTB patients. Furthermore, the serum levels of 3 proteins were significantly different among 3 PTB groups. FN level was significantly higher in the moderate PTB group, compared with patients in the minimal and advanced PTB groups (P < 0.05, P < 0.01). PEPD level was significantly higher in the moderate PTB group, compared with the minimal PTB group (P < 0.05). Analysis of clinical data showed that serum albumin, C-reactive protein (CRP), prealbumin, and C4 were significantly higher (P < 0.05), while serum globulin was significantly lower in patients with PTB (P < 0.001). A significant negative correlation was found between C4b and albumin, prealbumin. On the other hand, a significant positive correlation was found between C4b and globulin, CRP, PEPD, as well as between PEPD and CRP (P < 0.05).


Our study showed that C4b, FN, and PEPD are associated with tissue damage, granuloma formation, and cavity formation, respectively, in patients with PTB. The present study provides a new experimental basis to understand the pathogenesis and pathological changes of PTB.

Serum; Pulmonary tuberculosis; Complement C4b; Fibronectin; Prolidase; Granuloma; Cavity