HLA-A, B, DR, and DQ Antigens in Black Patients with Idiopathic Dilated Cardiomyopathy Breminand Maharaj, MB, ChB, FCP(SA), and Michael G. Hammond,
PhD
he HLA antigens, which are encoded by closely arranged genes on the short arm of the sixth chromol= some, influence the predisposition to several diseases.’
black patients with this disease to determine if immunogenetic factors could be involved in the pathogenesis of idiopathic dilated cardiomyopathy.
Some with initially weak associations with HLA-A and HLA-B antigens have been found to have stronger associations with HLA-DR antigens.2 Since a genetic predisposition to the development of idiopathic dilated cardiomyopathy has been postulated, and since there is little information on the relation between antigens at the DR and DQ loci of the HLA system and idiopathic dilated cardiomyopathy,3-5 we performed HLA typing in a group of
HLA-A and HLA-B typing was carried out in 62 black patients with idiopathic dilated cardiomyopathy who had been admitted and evaluated at King Edward VIII Hospital, Durban, and HLA-DR and HLA-DQ typing was performed in 57 of these individuals; all had evidence of global hypokinesis on echocardiography. None had any disease other than idiopathic dilated cardiomyopathy; habitual alcoholics and hypertensives were excluded. Coronary angiography was not performed in any of the patients because coronary artery disease is rare in the black population of South Africa.6*7 Patients were aged between 17 and 63 years. The control group consisted of 1,416 normal adults for the HLA-A and HLA-B typing, 220 for the HLA-DR typing and I98 .for the HLA-DC!- taping. Although over 2.000 individ--uals have been tested for the HLA-DQ locus in our laboratory, the majority were caucasoid orpatients with
From the Department of Experimental and Clinical Pharmacology, University of Natal Medical School and Natal Institute of Immunol* gy, Box 17039, Congella, 4013, Durban, South Africa. This study was supported in part by a grant from the South African Medical Research Council. Manuscript received November 20, 1989; revised manuscript received and accepted January 29, 1990. TABLE
I Frequencies
of HLA-A
Antigens
(%)
Antigen
E62)
Control Subjects (n = 1,416)
Al A2 A3 All A23 A24 A25/34 A26 A28 A29 A30 A31 A32 Aw33 One antigen
11.3 27.4 16.1 0.0 12.9 3.2 14.5 9.7 19.4 12.9 35.5 4.8 3.2 8.1 21.0
6.4 21.4 12.6 0.1 18.3 4.9 13.5 10.5 20.9 17.1 37.4 6.0 2.38 2.2 26.4
III
Frequencies PtS
Antigen
(n = 57)
DRl DR2 DR3 DR4 DR5 DRw6 DR7 DRw8 DR9 DRwlO DRl+ DRwlO One antigen
12.3 29.8 28.1 7.0 38.6 24.6 14.0 5.3 0.0 8.8 21.1 31.6
of HIA-DR
, Antigens
Control Subjects (n = 412) 4.6 24.0 36.2 35.2 14.6 15.3 2.9 0.7 2.2 6.8 54.4
(%)
I
p Value
Corrected p Value
PhD
he HLA antigens, which are encoded by closely arranged genes on the short arm of the sixth chromol= some, influence the predisposition to several diseases.’
black patients with this disease to determine if immunogenetic factors could be involved in the pathogenesis of idiopathic dilated cardiomyopathy.
Some with initially weak associations with HLA-A and HLA-B antigens have been found to have stronger associations with HLA-DR antigens.2 Since a genetic predisposition to the development of idiopathic dilated cardiomyopathy has been postulated, and since there is little information on the relation between antigens at the DR and DQ loci of the HLA system and idiopathic dilated cardiomyopathy,3-5 we performed HLA typing in a group of
HLA-A and HLA-B typing was carried out in 62 black patients with idiopathic dilated cardiomyopathy who had been admitted and evaluated at King Edward VIII Hospital, Durban, and HLA-DR and HLA-DQ typing was performed in 57 of these individuals; all had evidence of global hypokinesis on echocardiography. None had any disease other than idiopathic dilated cardiomyopathy; habitual alcoholics and hypertensives were excluded. Coronary angiography was not performed in any of the patients because coronary artery disease is rare in the black population of South Africa.6*7 Patients were aged between 17 and 63 years. The control group consisted of 1,416 normal adults for the HLA-A and HLA-B typing, 220 for the HLA-DR typing and I98 .for the HLA-DC!- taping. Although over 2.000 individ--uals have been tested for the HLA-DQ locus in our laboratory, the majority were caucasoid orpatients with
From the Department of Experimental and Clinical Pharmacology, University of Natal Medical School and Natal Institute of Immunol* gy, Box 17039, Congella, 4013, Durban, South Africa. This study was supported in part by a grant from the South African Medical Research Council. Manuscript received November 20, 1989; revised manuscript received and accepted January 29, 1990. TABLE
I Frequencies
of HLA-A
Antigens
(%)
Antigen
E62)
Control Subjects (n = 1,416)
Al A2 A3 All A23 A24 A25/34 A26 A28 A29 A30 A31 A32 Aw33 One antigen
11.3 27.4 16.1 0.0 12.9 3.2 14.5 9.7 19.4 12.9 35.5 4.8 3.2 8.1 21.0
6.4 21.4 12.6 0.1 18.3 4.9 13.5 10.5 20.9 17.1 37.4 6.0 2.38 2.2 26.4
III
Frequencies PtS
Antigen
(n = 57)
DRl DR2 DR3 DR4 DR5 DRw6 DR7 DRw8 DR9 DRwlO DRl+ DRwlO One antigen
12.3 29.8 28.1 7.0 38.6 24.6 14.0 5.3 0.0 8.8 21.1 31.6
of HIA-DR
, Antigens
Control Subjects (n = 412) 4.6 24.0 36.2 35.2 14.6 15.3 2.9 0.7 2.2 6.8 54.4
(%)
I
p Value
Corrected p Value
