Photobiomodulation of Pain and Inflammation in Microcrystalline Arthropathies: Experimental and Clinical Results

OBJECTIVE

This article presents the results of laser therapy in crystal (hydroxyapatite, calcium pyrophosphate, and urates) deposition-induced arthritis in rats and the clinical applications in humans.

BACKGROUND DATA

Microcrystalline arthropathies are prevalent among geriatric patients, who are more vulnerable to the side effects of drugs. The effectiveness of laser therapy for pain relief, free of side effects, has been reported in painful conditions.

METHODS

Two milligrams of each of the above-mentioned crystals was injected in both joints of the back limbs in three groups of rats; these groups were then treated with laser irradiation. Three other groups received no treatment after the injections. We determined the plasmatic levels of inflammatory markers (fibrinogen, prostaglandin E2, and TNF(alpha)), tissues (prostaglandin E(2)) and conducted anatomopathological studies. Twenty-five patients with acute gout arthritis were randomized into two groups and treated over 5 days: group A, diclofenac 75 mg orally, twice a day; and group B, laser irradiation once a day. Forty-nine patients with knee chronic pyrophosphate arthropathy were randomized into two groups and treated over 21 days; group A, diclofenac 50 mg orally, twice a day; and group B, laser irradiation once a day. Thirty patients with shoulder chronic hydroxyapatite arthropathy were randomized into two groups and treated over 21 days; group A, diclofenac 50 mg orally, twice a day; and group B, laser irradiation once a day.

RESULTS

Fibrinogen, prostaglandin E(2), and TNF(alpha) concentrations in the rats injected with crystals and treated with laser decreased significantly as compared with the groups injected with crystals without treatment. Both laser therapy and diclofenac achieved rapid pain relief in patients with acute gouty arthritis without significant differences in efficacy. Laser therapy was more effective than diclofenac in patients with chronic pyrophosphate arthropathy and in patients with chronic apatite deposition disease.

CONCLUSION

Laser therapy represents an effective treatment in the therapeutic arsenal of microcrystalline arthropathies.

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.

Effects of diclofenac sodium and He:Ne laser irradiation on plasmatic fibrinogen levels in inflammatory processes

OBJECTIVE

The aim of the present work was to determine the possible synergic effect on the concentration of plasma fibrinogen (PF) by injecting diclofenac sodium associated with laser therapy postsurgery.

SUMMARY BACKGROUND DATA

Nonsteroidal anti-inflammatory drugs (NSAIDs) and He:Ne laser irradiation as a therapy were used to inhibit the effects generated by inflammation. Tissue injury produces significant increases in PF levels, which are reduced to normal values by administration of NSAIDs or laser irradiation of the injured zone.

MATERIALS AND METHODS

Rate were divided into groups in which different presurgical and postsurgical treatment were used; the inflammation was induced by laparotomy.

RESULTS

Parenteral diclofenac or He:Ne laser irradiation used separately in normal rats did not produce changes in the PF levels. Diclofenac and laser irradiation combined postsurgery produced a significant reduction of PF levels compared with normal values, or with groups that were injected or irradiated postsurgically.

CONCLUSION

The inflammatory response could be reduced by the effect of the diclofenac sodium upon the COX-2/COX-1 inhibitory relation associated with the photobiological effect of the He:Ne laser.