Pustular psoriasis and aseptic purulent arthritis: possible role of leukotrienes B4 and C4 in a flare of synovitis.
BACKGROUND
Arthritis is a frequent complication of pustular psoriasis. However, the mechanism of onset of this arthritis still remains unclear.


OBJECTIVE
The present study was conducted to determine whether leukotriene (LT) B4 or LTC4 is one of the proinflammatory mediators that possibly enhance exacerbation of the arthritis lesions.


METHODS
We investigated the condition of the arthritis and autopsy findings of two cases of generalized pustular psoriasis with the severe complication of aseptic purulent arthritis. We also measured the synovial fluid levels of LTB4 and LTC4 by radioimmunoassay.


RESULTS
The collected synovial fluid was purulent, but nonbacterial, and the synovium of the knee joint showed histopathologic evidence of polymorphonuclear leukocyte (PMN) invasion, edema and dilatation of small vessels showing similarity to a histologic reaction in the skin lesions. The immunoreactive (i-) LTB4 and i-LTC4 in the samples significantly exceeded the amount measured in osteoarthritis patients used as the controls.


CONCLUSIONS
Thus, i-LTB4 and i-LTC4 appear to be generated in the arthritis lesions of pustular psoriasis, the former attracting PMNs to the joints and the latter causing exudation of synovial fluid.
Kawana
S
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Division of Dermatology, St. Luke's International Hospital, Tokyo, Japan.
Nishiyama
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D000368:Aged; D001168:Arthritis / Q000209:etiology* / Q000378:metabolism; D005260:Female; D006801:Humans; D007975:Leukotriene B4 / Q000378:metabolism; D017997:Leukotriene C4 / Q000378:metabolism; D015289:Leukotrienes / Q000032:analysis / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000209:etiology; D009504:Neutrophils / Q000502:physiology; D011565:Psoriasis / Q000150:complications* / Q000503:physiopathology; D011863:Radioimmunoassay; D013582:Synovial Fluid / Q000378:metabolism*; D013585:Synovitis / Q000276:immunology / Q000378:metabolism*
D015289:Leukotrienes; D007975:Leukotriene B4; D017997:Leukotriene C4