[Expression of heat shock protein 90 in peripheral blood mononuclear cells of children with myasthenia gravis].

OBJECTIVE

Myasthenia gravis is an autoimmunity disease and its pathogenesis has not been fully identified. Heat shock protein 90 (HSP90) shows an abnormal expression in other autoimmunity diseases. This study examined the mRNA expression of two isoforms of HSP90 in peripheral blood mononuclear cells (PBMC) and serum cortisol content in children with myasthenia gravis.

METHODS

Thirty-six children with myasthenia gravis and 19 healthy children were enrolled. Serum cortisol content was measured by the chemiluminescence assay. The expression of HSP90alpha and HSP90beta mRNA in PBMC was detected by the RT-PCR technique.

RESULTS

The mRNA expression of HSP90alpha (0.7329+/- 0.2120) and HSP90beta (0.7193+/- 0.2869) in children with myasthenia gravis was significantly higher than that in healthy controls (0.5574+/- 0.2084 and 0.4892+/- 0.2104 respectively) (P<0.01). Serum cortisol content (285.04+/- 146.39 nmol/L) in children with myasthenia gravis was also higher than that in the healthy controls (196.25+/- 64.52 nmol/L) (P<0.01).

CONCLUSIONS

The high mRNA expression of HSP90alpha and HSP90beta in PBMC might be associated with the development of myasthenia gravis. The high serum cortisol level indicates a high stress state or might be correlated to the glucocorticoid receptor abnormality in children with myasthenia gravis.