Expression of heat shock proteins and its clinical relevance in rheumatic diseases

ABSTRACT

Rheumatic diseases [RDs] are characterized by acute and chronic inflammation, and autoimmunity plays a major role in their pathogenesis. The presence of antibodies against heat shock proteins [HSPs] has been reported to occur in several autoimmune rheumatic diseases. This study assesses the expression of HSPs [70 and 90 KD] in the peripheral blood mononuclear cells [PBMCs] of patients with rheumatoid arthritis [RA] [n=20], and systemic lupus erythematosus [SLE] [n=20], as compared to osteoarthritis [OA] [n=20] and normal control volunteers [n=20]. Expression of HSPs was analyzed using protein electropheresis and immunoblotting techniques. The results revealed that HSP 90 is expressed in 40% of lupus patients versus 20, 10 and 5% in rheumatoid, osteoarthritis and normal controls [P<0.05]. Yet, both HSP 90 and 70 expression cannot differentiate between active and non active lupus patients. The erythrocyte sedimentation rate was the only laboratory test that showed significant difference [P< 0.01] between HSP +ve and -ve lupus patients. As regards rheumatoid arthritis and osteoarthritic patients, no increase of HSP expression could be detected when compared to normal controls. It is concluded that HSP 90 expression is more likely to differentiate lupus patients from normal controls as well as patients with other rheumatic diseases. However, it cannot be used to assess the clinical state of the disease