Measurement and prevalence of circulating ADAMTS13-specific immune complexes in autoimmune thrombotic thrombocytopenic purpura.
J Thromb Haemost
; 12(3): 329-36, 2014.
Article
in En
| MEDLINE
| ID: mdl-24354764
ABSTRACT
BACKGROUND:
The formation of ADAMTS13-specific circulating immune complexes (CICs) may be a pathophysiologic mechanism in autoimmune thrombotic thrombocytopenic purpura (TTP), but has not been systematically investigated.OBJECTIVES:
(a) To develop an assay for ADAMTS13-specific CICs; (b) to evaluate their prevalence in autoimmune TTP; and (c) to assess their association with ADAMTS13-related measurements and clinical features in autoimmune TTP patients. PATIENTS/METHODS:
We developed and validated an ELISA method for ADAMTS13-specific CICs. ADAMTS13-specific CICs were searched for in 55 patients with autoimmune TTP from the Milan TTP Registry (URLhttp//www.ttpdatabase.org/) and 28 controls. The associations between ADAMTS13-specific CIC levels and ADAMTS13 activity, antigen, anti-ADAMTS13 IgGs and acute TTP clinical features were assessed by multivariate linear regression.RESULTS:
Intra- and inter-assay coefficients of variation of the new test were 5.3 and 9.6%. In 36 patients with severe ADAMTS13 deficiency and anti-ADAMTS13 autoantibodies, the prevalence of ADAMTS13-specific CICs was 47% (n = 17; 95% confidence interval [CI], 32-63%). ADAMTS13-specific CICs were detected also in seven of 19 (37%; 95% CI, 19-59%) patients with reduced ADAMTS13 activity, but apparently negative anti-ADAMTS13 autoantibodies. ADAMTS13-specific CICs were not associated with ADAMTS13 activity, antigen or anti-ADAMTS13 IgGs. In patients with acute TTP, increasing levels of ADAMTS13-specific CICs were associated with a higher number of plasma-exchange procedures required to attain remission (per 0.1 increase in normalized OD values, beta, 2.9; 95% CI, -0.7 to 6.5).CONCLUSIONS:
Approximately one to two-thirds of patients with autoimmune TTP display ADAMTS13-specific CICs. A thorough investigation of the prognostic relevance of ADAMTS13-specific CIC levels in autoimmune TTP is warranted.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Purpura, Thrombotic Thrombocytopenic
/
Autoimmune Diseases
/
ADAM Proteins
/
Antigen-Antibody Complex
Type of study:
Prevalence_studies
/
Prognostic_studies
/
Risk_factors_studies
Limits:
Adult
/
Female
/
Humans
/
Male
/
Middle aged
Language:
En
Journal:
J Thromb Haemost
Journal subject:
HEMATOLOGIA
Year:
2014
Document type:
Article
Affiliation country: