Rapid whole blood flow cytometric test to detect ICOS deficiency in patients with common variable immunodeficiency.
OBJECTIVE
Common variable immunodeficiency (CVID) is the most common primary immunodeficiency. With respect to underlying defects it comprises a heterogeneous group of deficiencies. For some patients, distinct phenotypical abnormalities have been described, e.g. partial CD40L deficiency or complete ICOS deficiency. For the diagnosis of CD40L deficiency, a rapid whole blood flow cytometric method has been described several years ago. We aimed to determine if the same method can be used to diagnose ICOS deficiency.


METHODS
Whole blood from 8 healthy volunteers was stimulated for 4 and 20 h with phorbol 12-myristate 13-acetate (PMA) and ionomycin. Induction of ICOS expression was analyzed on CD8-CD3+ lymphocytes using three-color flow cytometry. Blood from a patient with diagnosed ICOS deficiency was also analyzed.


RESULTS
Whole-blood stimulation with PMA and ionomycin for 20 h resulted in a significant induction of ICOS expression on CD8-CD3+ lymphocytes in healthy volunteers. Four-hour incubation also demonstrated ICOS upregulation but to a much lower extent. In CD8-CD3+ lymphocytes from an ICOS-deficient patient, no ICOS expression could be induced following 20 h of stimulation.


CONCLUSIONS
ICOS expression can be analyzed using a rapid whole blood flow cytometric test.
Bunk
Robert
R
Institute of Medical Immunology, University Hospital, Campus Charité Mitte, Berlin, Germany.
Dittrich
Anna-Maria
AM
Schulze
Ilka
I
Horn
Julia
J
Schmolke
Kathrin
K
Volk
Hans-Dieter
HD
Wahn
Volker
V
Höflich
Conny
C
D015703:Antigens, CD / Q000097:blood; D000945:Antigens, Differentiation, T-Lymphocyte / Q000097:blood* / Q000378:metabolism; D017252:CD3 Complex / Q000097:blood; D018414:CD8-Positive T-Lymphocytes / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D017074:Common Variable Immunodeficiency / Q000097:blood* / Q000473:pathology; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D060889:Inducible T-Cell Co-Stimulator Protein; D015759:Ionomycin / Q000494:pharmacology; D037181:Lectins, C-Type; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D000099192:CD69 Antigens
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D060889:Inducible T-Cell Co-Stimulator Protein; D015759:Ionomycin; D037181:Lectins, C-Type; D013755:Tetradecanoylphorbol Acetate; D000099192:CD69 Antigens; C556692:ICOS protein, human