Læknablaðið : fylgirit - 01.06.1982, Blaðsíða 47

34
HLA AND RETINOPATHY IN GENOTYPED TYPE 1 (INSULIN-DEPENDENT)
DIABETICS IN ICELAND. P.. Danielsen^, A. Ámason^, T. Helgason*
and F. Jónasson^. lDiabetic Clinic, Landspítalinn, Univers'ity
Hospital, 2 The Blood Bank, Genetic Department and--^Landakot
Hospital, Eye Department; Reykjavik Iceland.
The relationship between HLA specificities and retinopathy
in Type 1 diabetics has been debated. We analysed the distri-
bution of HLA-loci and defined haplotype parts (genotypes,
including Bf-alleles) in relation to retinopathy in Type 1
(insulin-dependent) diabetics in Iceland. One hundred and six-
ty such patients have been HLA- and Bf-typed, representing
approximately 60% of all known Type 1 diabetics in Iceland at
time of study. Most of these (128) were genotyped. For compar-
ison, 228 healthysubjects were also HLA and Bf genotyped.
212 (76% of total) Type 1 diabetics have been assessed by
fundus photography for presence of retinopathy. From this
material the following groups were compiled for the present
study:- 1) Patients with duration of diabetes of 15 years or
more with age of onset of diabetes of less than 30 years. These
patients were divided into those with proliferative retinopathy
and those with no retinopathy. 2) Patients with duration of
diabetes of 10 years or more and diagnosed at any age; again
these were divided into two groups according to the absence or
presence of any retinopathy. Compared groups were statistically
matched for duration of diabetes and age at diagnosis.
In Group 1), HLA-Bg was similarly distributed in those
with proliferative retinopathy and in those without retinopathy.
In contrast, HLA-B15 showed a reduced frequency and relative
risk in the pts with proliferative retinopathy compared to
those without retinopathy (RRc 3.68 versus 5.36, respectively).
In Group 2) a similar pattem of results was observed. Thus
HLA-B15 decreased the risk ratio for any degree of retinopathy
significantly 2.9 times (p= 0.045). Persuing this further the
haplotype part A2~Bl5-Bfs was found to decrease the risk for
retinopathy 8.5 times (p= 0.12). These findings are in contr-
ast to previous reports and will be further discussed.