We were most interested in the report by Joe Dylewski and colleagues on acute monoarticular arthritis caused by birefringent Maltese cross-like crystals composed of lipids.1 Arthritis has been reported in patients with hyperlipidemias, especially type II.2 Although Glueck and colleagues3 reported synovitis in such patients, the body of evidence favours a periarticular site of inflammation.4 Cholesterol crystals have been identified in some patients but do not appear to be particularly inflammatory.5 To date we know of no other report of Maltese cross-like crystals in patients with arthritis associated with hyperlipoproteinemia.
Why arthritis is associated with hyperlipoproteinemia remains a mystery. Perhaps high levels of blood blood lipids of a certain type act as a source of lipid-bound macroenzymes.6 It is perhaps germane that high concentrations of trypsin and lipase resulting from pancreatic disease cause synovial fat necrosis with either a mono- or polyarthritis and subcutaneous necrosis.7,8
References
- 1.↵
Dylewski J, Awan Z, Roy, I. Acute monoarticular arthritis caused by Maltese cross-like crystals. CMAJ 2005;172(6):741-2.
- 2.↵
Rifkind BM. The hyperlipoproteinaemias. B J Hosp Med 1970;4:683-92.
- 3.↵
Glueck EJ, Levy RI, Frederickson DS. Acute tendinitis and arthritis. A presenting symptoms of familial type II hyperlipoproteinemia. JAMA 1968;13:2895-7.
- 4.↵
Struthers GR, Scott DL, Bacon PA, Walton KW. Musculoskeletal disorders in patients with hyperlipideamia. Ann Rheum Dis 1983;42:519-23.
- 5.↵
Fam AG, Sugai M, Gertner E, Lewis A. Cholesterol “tophus.” Arthritis Rheum 1983;26:1525-8.
- 6.↵
Remaley AT, Wilding P. Macroenzyems: biochemical characterization, clinical significance, and laboratory detection. Clin Chem 1989;35:2261-70.
- 7.↵
Hughes PSH, Apisarnthanrax P, Mullins JF. Subcutaneous fat necrosis associated with pancreatic disease. Arch Dermatol 1975;111:506-10.
- 8.↵
Smuckler NM, Schumacher HR, Pascual E, Brown S, Ryan WE, Sadeghian MR. Synovial fat necrosis associated with ischemic pancreatic disease. Arthritis Rheum 1979;22(5):547-53.