Expression of the 60 kDa and 71 kDa heat shock proteins and presence of antibodies against the 71 kDa heat shock protein in pediatric patients with immune thrombocytopenic purpura.
BACKGROUND
Immune thrombocytopenic purpura (ITP) is an autoimmune disease characterized by platelet destruction resulting from autoantibodies against platelet proteins, particularly platelet glycoprotein IIb/IIIa. Heat shock proteins (Hsp) have been shown to be major antigenic determinants in some autoimmune diseases. Antibodies to Hsps have also been reported to be associated with a number of pathological states.


METHODS
Using western blot, we measured the levels of the 60 kDa heat shock protein (Hsp60) and of the inducible 71 kDa member of the Hsp70 family (Hsp71) in lymphocytes and the presence of antibodies against these hsps in plasma of 29 pediatric patients with ITP before the treatment and in 6 other patients before and after treatment.


RESULTS
Interestingly only one out of 29 patients showed detectable Hsp60 in lymphocytes while this heat shock protein was detected in the 30 control children. Hsp71 levels were slightly lower in lymphocytes of patients with ITP than in controls (1567.8 ± 753.2 via 1763.2 ± 641.8 integrated optical density (IOD) units). There was a small increase of Hsp71 after recovery from ITP. The titers of plasma antibodies against Hsp60 and Hsp71 were also examined. Antibodies against Hsp71 were more common in ITP patients (15/29) than in control children (5/30). The titer of anti-Hsp71 was also higher in children patients with ITP. The prevalence of ITP children with antibodies against Hsp71 (51.7%) was as high as those with antibodies against platelet membrane glycoproteins (58.3%).


CONCLUSIONS
In summary, pediatric patients with ITP showed no detectable expression of Hsp60 in lymphocytes and a high prevalence of antibody against Hsp71 in plasma. These changes add to our understanding of the pathogenesis of ITP and may be important for the diagnosis, prognosis and treatment of ITP.
Xiao
Chengfeng
C
Institute of Occupational Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
Chen
Sheng
S
Institute of Occupational Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
Yuan
Mingchun
M
Department of Haematological Diseases, Wuhan Children Hospital, Wuhan 430015, China.
Ding
Fuyue
F
Department of Haematological Diseases, Wuhan Children Hospital, Wuhan 430015, China.
Yang
Dongliang
D
Division of Clinical Immunology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology,1095 Jiefang Avenue, Wuhan 430030, China.
Wang
Ruibo
R
Institute of Occupational Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
Li
Jianxin
J
Department of Haematological Diseases, Wuhan Children Hospital, Wuhan 430015, China.
Tanguay
Robert M
RM
Laboratory of Cell and Developmental Genetics, Dept Medicine, Faculty of Medicine, Pavillon Marchand, Université Laval, Québec, Canada, G1K 7P4.
Wu
Tangchun
T
Institute of Occupational Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.