title: Photobiomodulation of pain and inflammation in microcrystalline arthropathies: experimental and clinical results.
abstract: 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
  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.
  
  
  CONCLUSIONS
  Laser therapy represents an effective treatment in the therapeutic arsenal of microcrystalline arthropathies.
authors.affiliation: Instituto Argentino de Medicina Láser (IAMEL), Rosario, Argentina. soriano@steel.com.ar
authors.forename: F
authors.initials: F
authors.lastname: Soriano
authors.forename: V
authors.initials: V
authors.lastname: Campana
authors.forename: M
authors.initials: M
authors.lastname: Moya
authors.forename: A
authors.initials: A
authors.lastname: Gavotto
authors.forename: J
authors.initials: J
authors.lastname: Simes
authors.forename: M
authors.initials: M
authors.lastname: Soriano
authors.forename: R
authors.initials: R
authors.lastname: Soriano
authors.forename: L
authors.initials: L
authors.lastname: Spitale
authors.forename: J
authors.initials: J
authors.lastname: Palma
mesh_terms: D000818:Animals; D018771:Arthralgia / Q000628:therapy*; D001169:Arthritis, Experimental / Q000628:therapy*; D015415:Biomarkers / Q000097:blood; D002131:Calcium Pyrophosphate; D004008:Diclofenac / Q000627:therapeutic use; D015232:Dinoprostone / Q000097:blood; D017886:Durapatite; D005260:Female; D005340:Fibrinogen / Q000032:analysis; D006073:Gout / Q000628:therapy*; D006801:Humans; D053685:Laser Therapy; D008875:Middle Aged; D051381:Rats; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis; D014527:Uric Acid
chemical_list: D015415:Biomarkers; D014409:Tumor Necrosis Factor-alpha; D004008:Diclofenac; D014527:Uric Acid; D005340:Fibrinogen; D017886:Durapatite; D015232:Dinoprostone; D002131:Calcium Pyrophosphate