He-Ne laser on microcrystalline arthropathies.

Objective: The objective of this work is to assess the anti-inflammatory capacity of He-Ne laser therapy as determined by the plasmatic levels of inflammatory markers, fibrinogen, and TNFalpha and by histopathological study in rats with arthropathy induced by calcium pyrophosphate crystals.

Background data: Microcrystalline arthropathies are a group of diseases characterized by the deposit of different crystals in joints.

Materials and methods: Two milligrams of dicalcium pyrophosphate crystals (DCPP) were injected in both joints of the lower limbs of rats during 2 days. A group was treated with laser of He-Ne (6 mW) on the injected joints during 3 consecutive days. After 96 h of the first injection, animals were sacrificed to determine TNFalpha using the ELISA method and fibrinogen was assessed using spectrophotometry. Sections from the lower limbs were used for histopathology.

Results: A statistically significant increase (p < 0.001) in plasma fibrinogen levels and TNFalpha was noted between the control group and the laser-treated group. The histological transversal section of a posterior limb joint of a rat injected with DCPP showed fibroadipose tissue with diffuse chronic infiltrate. The histopathology of the group of rats injected with DCPP and subsequently treated with He-Ne laser showed no inflammatory response.

Conclusion: He-Ne laser treatment in the microcrystalline arthropathy induced in rats by DCPP injection might have an antiinflammatory effect, evaluated by fibrinogen plasma levels and TNF-alpha (inflammatory markers) and by the histopathology regressive process.