Significant correlation between the CD63 assay and the histamine release assay in chronic urticaria.
BACKGROUND
Antibodies directed to the alpha subunit of the high affinity IgE receptor and the IgE molecule are proposed to be of pathogenetic relevance in a group of patients with chronic urticaria (CU). The diagnosis of autoimmune chronic urticaria (ACU) is difficult; the autologous serum skin test (ASST) seems to be a useful screening test, but reliable, additional confirmatory methods are needed.


OBJECTIVE
To assess the diagnostic value of a modified serum-induced basophil activation test, the CD63 expression assay, in the diagnosis of ACU by comparing the results of the CD63 assay with the results of the histamine release (HR) test, the ASST and serum levels of soluble CD40 ligand (sCD40L).


METHODS
Using basophils from an atopic (DA) and a nonatopic (DNA) donor the activity of sera of 72 patients with CU were measured in HR assay by enzyme-linked immunosorbent assay and in CD63 expression assay by flow cytometry. An ASST was carried out in all patients; in 30 of the 72 patients sCD40L was detected and correlations were derived between the different assays. Sera of 20 normal controls and 26 patients with systemic autoimmune diseases were also tested in the HR assay and in the CD63 expression assay.


RESULTS
Histamine-releasing activity was detected in the sera of 51% (DA) and 32% (DNA) of CU patients and 57% (DA) and 28% (DNA) of sera upregulated CD63 expression on the surface of basophils from the different donors. There was a significant correlation between the HR and the CD63 assays carried out on both donors, but the ASST showed a strong correlation with the HR assay only for basophils from the DA. The serum level of sCD40L was significantly higher in patients with CU compared with controls, but the difference between the autoimmune and the nonautoimmune groups was not significant.


CONCLUSIONS
The CD63 expression assay seems to be a reliable functional test in the diagnosis of ACU, particularly if highly sensitive donor basophils are used, but the determination of the sCD40L serum level was not sufficient to differentiate between the autoimmune and the nonautoimmune patient groups.
Szegedi
A
A
Department of Dermatology, Medical and Health Science Centre, University of Debrecen, 98 Nagyerdei str., Debrecen 4012, Hungary. aszegedi@jaguar.dote.hu
Irinyi
B
B
Gál
M
M
Hunyadi
J
J
Dankó
K
K
Kiss
E
E
Sipka
S
S
Szegedi
G
G
Gyimesi
E
E
D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D015703:Antigens, CD / Q000032:analysis*; D001491:Basophils / Q000276:immunology*; D001681:Biological Assay; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D023201:CD40 Ligand / Q000097:blood; D016022:Case-Control Studies; D002908:Chronic Disease; D005260:Female; D006636:Histamine Release; D006801:Humans; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D010980:Platelet Membrane Glycoproteins / Q000032:analysis*; D012882:Skin Tests; D018709:Statistics, Nonparametric; D060149:Tetraspanin 30; D014581:Urticaria / Q000175:diagnosis*
D015703:Antigens, CD; D015415:Biomarkers; C554586:CD63 protein, human; D010980:Platelet Membrane Glycoproteins; D060149:Tetraspanin 30; D023201:CD40 Ligand