Improvement of bone metabolism after infliximab therapy in Crohn's disease

Background: Osteoporosis has received increasing attention as a potential complication of Crohn's disease (CD). Among cytokines TNF-alpha plays a pivotal role in the pathogenesis of CD by inducing a wide variety of inflammatory responses, including bone resorption. Although infliximab (INX) is capable to cause a rapid beneficial change in the course of CD, only few data are present about its effect on bone metabolism.

Aims: Our aim was to evaluate the effect of INX on bone metabolism in CD patients.

Patients and methods: 17 patients with fistulizing CD treated with 5mg INX per kg (0, 14^th and 42^nd day) were studied. Biochemical markers of bone formation (osteocalcin, OC) and bone resorption (beta-CrossLaps, bCL) were measured from sera before administrations of INX. Significance 0. day vs. 14^th day was p=0.05, and 0. day vs.42th day was 0.05 in OC and 0.01 in sAP.

Results:

	0. day	14.th day	42th day
bCL (ng/ml)	0.64±0.38	0.46±0.27*	0.49±0.29
OC (ng/ml)	21.54±13.1	23.73±16.3	29.9±26.9*
sAP (U/l)	228±65.26	219±89.12	200±75.1*

There was a positive correlation between bCL and AP levels at the beginning of the study (r=0.535, p<0.05), while no correlation was found between OC and AP levels at the same time. At day 42 positive correlation was presented between OC and AP levels (r=0.664, p<0.05).

Conclusion: INX therapy in CD patients displayed a rapid influence on bone metabolism by enhancing bone formation and decreasing bone resorption. In addition to its mucosal effect affecting the bone homeostasis indicate a further rationale usage of TNF-alpha blockade in the therapy of CD.