Tissue Antigens (1976), 7, 233-237 Published by Munksgaard, Copenhagen, Denmark N o part may be reproduced by any process without written permission from the author(s)
Histocompatibility (HLA) Antigens and Diabetic Microangiopathy" J. Barbosa, H . Noreen, L. Emme, F. Goetz, R. Simmons, A. deleiva, J. Najarian and E.J. Yunis Departments of Medicine, Laboratory Medicine and Pathology, and Surgery, University of Minnesota Medical School, Minneapolis, Minnesota, U.S.A. To gain further insight into the genetic determinants of diabetic small vessel disease, we studied 22 HLA antigens in 1 10 juvenile-onset, insulin-dependent diabetics with terminal glomerulosclerosis and retinopathy, who were being prepared for kidney transplant. HLA antigens were contemporarily determined in non-diabetic kidney transplant recipients and healthy controls. The frequency of antigens A 1 and B8 were significantly higher in diabetics than in controls (P < .02 and .01 l), but the frequency of BW15 was normal. The data arecompatible with the concept that juvenile diabetes with microangiopathy is one of the HLA-B8 associated disorders.
Received for publication 9 December 1975, accepted 26 JanuaT 1976
T h e extent to which genetic or metabolic factors influence the pathogenesis of diabetic microangiopathy has been widely debated. Recently reported associations between HLA specificities B8 and BW15 with juvenile-onset, insulin-dependent diabetes mellitus (Singal & Blajchman 1973, Nerup et al. 1974, Cudworth & Woodrow 1975, Nelson et al. 1975) have promised to clarify our understanding of the genetics of diabetes. However, none of these reports have related HLA specificity frequencies to manifestations of diabetic microangiopathy, namely retinopathy and glomerulosclerosis. We deemed it of interest, therefore, to study the frequency of the different HLA
*
antigens in a highly selected population of juvenile-onset, insulin-dependent diabetics with advanced glomerulosclerosis being accepted at the University of Minnesota kidney transplant program. We also determined HLA antigens in the recipient's living related donors, some of them with mild glucose intolerance.
Materials and Methods 1. Diabetic kidney recipients. Juvenile-onset (symptoms of diabetes and insulin administration started before age 30), insulindependent diabetics with glomerulosclerosis, advanced renal failure, and in most cases, proliferative retinopathy, were admit-
Published in abstract form in Clinical Research 23, 534A, 1975.
234
BARBOSA ET AL.
ted to the renal transplant program at the University of Minnesota Hospitals. There were 110 patients, all Caucasians, with a mean age of 35 years (range 23-48 years), 67 were males and 43 females. A more detailed clinical description of these patients has been published (Kjellstrand et al. 1973).
2. Living related donors to diabetic kidney recipients. Living related volunteer donors are frequently used at this institution. One or more of the recipients’ siblings and/or parents are not only tissue typed for HLA, but also admitted to the Clinical Research Center and studied for glucose tolerance. Eighty-eight volunteer potential kidney donors (mean age 40, range 18-46; 50 male, 38 female) have been studied. There were 61 siblings, 19 parents, and eight daughters, sons, nieces or nephews of the recipients. 3 . Non-diabetic kidney recipients and healthy controls. We have included HLA tissue typing of 165 subjects with non-diabetic nephropathy, transplanted contemporaneously with the diabetics, as well as a group of healthy controls (blood bank donors). All but two recipients, and all healthy controIs, were Caucasian. Methods
a) HLA typing. HLA antigens were determined with a standard two stage dye exclusion microcytotoxicity test (Amos et al. 1970), using a panel of 90 well-characterized antisera capable of detecting all defined HLA and most “W” specificities. Differences in HLA antigen frequencies between patients and controls were analyzed by chisquare analysis. P values were corrected for the number of specificities studied using the expression P = 1-(1-p)”, where p is the uncorrected value and the exponent the number of antigens studied. b) T h e kidney donors to diabetic relatives were given a 300 gram carbohydrate diet for
3 days before standard (OGT) and cortisolprimed (COGT) oral glucose tolerance tests were done as described before (Fajans & Conn 1954, Snegoski & Freier 1973). c) T h e average “relative risk’ for the presence of diabetes in individuals carrying a certain antigen was calculated using the expression fd (1-fc) fc (1-fd) where fd = frequency in diseased and fc frequency in controls.
Results Table 1 shows the frequencies of 22 HLA antigens in diabetic kidney transplant recipients (JODR), non-diabetic kidney recipients (NDR), and healthy controls. T h e incidence of HLA antigen A1 was significantly higher in diabetics than in healthy controls ( P = .02), whereas antigen B8 was significantly more frequent in diabetic than in non-diabetic kidney recipients (P = ,011) and healthy controls ( P = .011). There were no differences between male and female diabetics. T h e incidence of other antigens, including BW15, did not differ between the three groups. The average “relative risk” for the presence of diabetes with severe renal disease was increased 2.4 and 3.1 times in the individuals carrying HLA antigens A1 and B8 respectively. T h e volunteer potential donors to the diabetics were divided into Group I with both glucose tolerance tests normal (31 donors), Group I1 with normal OGT but abnormal COCT (29 donors), and Group 111 with both OGT and COGT abnormal (eight donors). Twenty donors had nondiagnostic tests (Group IV). Although there was a higher frequency of antigens A1 and B8 in Groups I and 11, it was not significantly different from controls, after correction of P values.
HLA AND DIABETIC MICROANGIOPATHY
Table 1 Frequency of HLA specificities i n diabetic (JODR) and non-diabetic kidney transplant recipients (NDR) and healthy controls (C)
HLA
J o D R (110)* NDR (165)*
%
c (217)*
%
%
Locus A A1 A2 A3 A9 A10 A1 1 A28 Awl9
47.3** 47.3 20.9 27.3 6.4 3.6 6.5 15.4
32.7 53.3 29.7 13.9 9.7 9.1 7.7 21.6
27.2 55.3 28.1 17.5 12.9 10.2 7.4 18.0
Locus B B5 B7 B8 B12 B13 B14 B18 B27 BWl5 BW16 BW17 BW22 BW35 BW40
10.9 13.6 45.5** 25.4 4.5 4.4 4.3 6.5 15.2 10.8 4.5 4.4 10.9 19.6
18.2 29.1 21.8 26.7 7.9 6.8 13.8 7.8 15.5 4.3 7.7
12.5 25.8 21.2 30.0 6.9 5.5 5.5 5.0 17.0 7.4 5.0
*
** ***
0.9
0.9
13.8 19.6
14.3 18.4
No. of subjects in each group. For W antigens there were only 46 subjects in JODR group and 116 in NDR group. P < .02 comparing JODR with C. P < ,011 comparing JODR with NDR and C.
There was an appreciably higher incidence of antigen B18 in non-diabetic recipients, which was significantly different from controls (P < .025), only before correction for the number of antigens; the relative risk for B18 in this group was 2.75.
Discussion Although the role of the genetic factor in the pathogenesis of diabetes is universally recognized, there is little agreement about the mode of genetic inheritance. Indeed, practi-
235
cally every genetic mechanism has been proposed (Rimoin 1971). Recently, a great deal of evidence has been marshalled in favor of genetic heterogeneity, i. e. several distinct disorders resulting from different gene mutations at several loci, and/or from different mutant alleles at the same locus, each of which includes carbohydrate intolerance (Rirnoin 1971), but are perhaps distinct from each other in important pathogenic and clinical aspects. Recent evidence has suggested that viral infections (Steinke & Taylor 1974) and autoimmunity (Lancet 1974) may have a pathogenic role in some cases of diabetes Reports of associations of HLA specificities B8 and BW15 with juvenile-onset, insulin-dependent diabetes (Singal & Blajchman 1973, Nerup et al. 1974, Cudworth & Woodrow 1975, Nelson et al. 1975), and a genetic linkage of HLA locus B with immune response genes (Blumenthal et al. 1974), has strengthened the autoimmune hypothesis of diabetes. Our finding of an association between HLA antigens A1 and B8, but not BW15, and diabetes with severe microangiopathy, adds a new dimension to genetic heterogeneity of diabetes. Particularly relevant to this association is the finding that among diabetic identical twins with early onset diabetes (< 40 years of age like most of our patients), only the concordant pairs showed a higher frequency of antigen B8 (Nelson et al. 1975). Clinical evidence indicated that the disease in concordant pairs was more prone to be complicated by proliferative retinopathy (Pyke & Tattersall 1973), than in the discordant pairs. The role of genetic versus metabolic determinants in the pathogenesis of diabetic microangiopathy is controversial. Siperstein et al. (1968) showed that 50% of the prediabetics (normal offspring of conjugal diabetic parents), and 98% of overtly diabetic patients had abnormally thickened
236
BARBOSA ET Al.
skeletal muscle capillary basement membrane, which suggests a major role of genetics in the pathogenesis of microangiopathy. However, others have not confirmed the capillary abnormality in prediabetics, and showed a correlation of the lesion with the duration of overt diabetes (Williamson et al. 197 I), suggesting a primary pathogenic role for the metabolic abnormality. T h e relationship of skeletal muscle basement membrane thickness with diabetic glomerulosclerosis has not been studied, but positive correlation with retinopathy has been reported (Yodaiken et al. 1975). Although similar renal vascular lesions such as hernochromatosis (Becker & Miller 1960) have been described in secondary diabetes, their incidence has usually been lower than in primary diabetes mellitus, as though there were genetic factors of considerable pathogenic importance in the latter, but not in the former. T h e association of HLA antigens A1 and B8, probably reflecting a high frequency o f haplotype Al-B8, with diabetes complicated by severe microangiopathy, supports the concept that juvenile onset diabetes (with microangiopathy) is one of the HLA-BSassociated autoimmune disorders. That antigen, as well as BW15, found in association with juvenile onset diabetes, seems to have useful prognostic significance. T h e study of HLA-I1 specificities in diabetes may further strengthen this concept. A high frequency of DW3 in juvenile onset diabetes has been claimed (Thomsen et al. 1975). T h e trend for a higher incidence of H1.A specificities A1 and B8 among related potential donors to kidney recipients may be due to either histocompatible donor selection, their relation to the diabetics, or the inclusion of subclinical diabetics in this group. There were no detectable differences for any of the antigens tested between donors in Group I (all tests for diabetes
normal), and Groups 11 to IV (at least one abnormal test), and there was a high concordance rate in donor-recipient pairs for antigen B8. T h e exclusion o f offspring, nieces and nephews, donors of diabetic recipients, did not change the results. Therefore, the increased incidence of that specificity among donors to diabetics is most likely due to histocompatible donor selection.
Acknowledgments
We are grateful to Ms. Jane Thompson for data compilation. Research was supported in part by: Bush Foundation, St. Paul, Mn., and U.S.P.H. Grants HL-06314, lROlHD08145, NIAID 72-54 Contract, and General Clinical Research Centers Program (RR-400), T h e Division o f Research Resources, N I H .
Rejerences Amos, D.H., Bashir, W., Boyle, W . , Macqueen,
M . E . & Tilikainen, A. (1970) A simple microcytotoxicity test. Transplantation 7, 220-223. Becker, D. & Miller, M. (1960) Presence of diaberic glomerulosclerosis in patients with hemochromatosis. New Engl. /. Med. 263, 367-374. Blumenthal, M.N.,Amos, D.B., Noreen, H . , Mendell, N . R . & Yunis, E.J. (1974) Genetic mapping of Ir locus in man: Linkage to second locus of HI.-A. Science 184,- 1301-1303. Cudworth, A.G. & Woodrow, J.C. (1975) HL-A system and diabetes mellitus. Diabetes 24, 345-349. Editorial (1974) Autoimmune diabetes mellitus. Lancet ii, 1.549-1550. Fajans. S.S. & Conn, J.W. (1954) Theapproach to the prediction of diabetes mellitus by modification of the glucose tolerance test with cortisone. Diabetes 3, 296-304. Kjellstrand, C.M., Simmons, R.L., Goetz, F.C., Buselmeier, T.J., Shideman. J.R., Hartitsch, B.V. & Najarian, J.S. (1973) Renal transplantation in patients with insulin dependent diabetes. Lancet ii, 4-8. Nelson, P.G., Pyke, D.A., Cudworth, A.G., Woodrow, T . C . & Batchelor, A. (1975) Histocompatibility antigens in diabetic identical twins. Lancet ii, 193-194.
HLA AND DIABETIC MICROANGIOPATHY
Nerup, J., Platz, P., Andersen, O.O., Christy, M., Lyngsoe, J., Poulsen, J. E., Ryder, L.P., Nielsen, L.S., Thomsen, M. & Svejgaard, A. (1974) HL-A antigens and diabetes mellitus. Lancet ii, 864-866. Pyke, D.A. & Tattersall, R.B. (1973) Diabetic retinopathy in identical twins. Diabetes 22, 6 13-6 18. Rimoin, D.L. (1971) Inheritance in diabetes mellitus. Med. Clin. N . Amer. 5 5 , 807-819. Singal, D.P. & Blajchman, M.A. (1973)Histocompatibility (HL-A) antigens, lymphocytotoxic antibodies and tissue antibodies in patients with diabetes mellitus. Diabetes 22, 428-432. Siperstein, M.D., Unger, R.H. & Madison, L.L. (1968) Studies of muscle capillary basement membrane in normal subjects, diabetics and pre-diabetics. J . clin. Invest. 47, 1973-1999. Snegoski, C.M. & Freier, E.F. (1973) Glucose determination by enzymatic method. Amer. J . Med. Technol. 39, 140-144. Steinke, J . &Taylor, K.W. (1974) Viruses and the etiology of diabetes. Diabetes 23, 631-633.
237
Thomsen, M., Platz, P., Andersen, O., Christy, M., Lyngs@e, J., Nerup, J., Rasmussen, K., Ryder L., Nielsen, L. & Svejgaard, A. (1975) MLC typing in juvenile diabetes mellitus and idiopathic Addison's disease. Transplanf. Rev. 22, 126-147. Williamson, J.R., Volger, N.J. & Kilo, C. (1971) Microvascular disease in diabetes. Med. Clin. N . Amer. 55, 847-860. Yodaiken, R.E., Menefee, M., Seftels H.C., Kew, M.C. & McClaren, M.J. (1975) Capillaries of South African diabetics. IV. Relation to retinopathy. Diabetes 24, 286-290.
Address: J. Barbosa, M.D. Dept. of Medicine University of Minnesota Medical School Minneapolis Minnesota 55455, U.S.A.
Histocompatibility (HLA) Antigens and Diabetic Microangiopathy" J. Barbosa, H . Noreen, L. Emme, F. Goetz, R. Simmons, A. deleiva, J. Najarian and E.J. Yunis Departments of Medicine, Laboratory Medicine and Pathology, and Surgery, University of Minnesota Medical School, Minneapolis, Minnesota, U.S.A. To gain further insight into the genetic determinants of diabetic small vessel disease, we studied 22 HLA antigens in 1 10 juvenile-onset, insulin-dependent diabetics with terminal glomerulosclerosis and retinopathy, who were being prepared for kidney transplant. HLA antigens were contemporarily determined in non-diabetic kidney transplant recipients and healthy controls. The frequency of antigens A 1 and B8 were significantly higher in diabetics than in controls (P < .02 and .01 l), but the frequency of BW15 was normal. The data arecompatible with the concept that juvenile diabetes with microangiopathy is one of the HLA-B8 associated disorders.
Received for publication 9 December 1975, accepted 26 JanuaT 1976
T h e extent to which genetic or metabolic factors influence the pathogenesis of diabetic microangiopathy has been widely debated. Recently reported associations between HLA specificities B8 and BW15 with juvenile-onset, insulin-dependent diabetes mellitus (Singal & Blajchman 1973, Nerup et al. 1974, Cudworth & Woodrow 1975, Nelson et al. 1975) have promised to clarify our understanding of the genetics of diabetes. However, none of these reports have related HLA specificity frequencies to manifestations of diabetic microangiopathy, namely retinopathy and glomerulosclerosis. We deemed it of interest, therefore, to study the frequency of the different HLA
*
antigens in a highly selected population of juvenile-onset, insulin-dependent diabetics with advanced glomerulosclerosis being accepted at the University of Minnesota kidney transplant program. We also determined HLA antigens in the recipient's living related donors, some of them with mild glucose intolerance.
Materials and Methods 1. Diabetic kidney recipients. Juvenile-onset (symptoms of diabetes and insulin administration started before age 30), insulindependent diabetics with glomerulosclerosis, advanced renal failure, and in most cases, proliferative retinopathy, were admit-
Published in abstract form in Clinical Research 23, 534A, 1975.
234
BARBOSA ET AL.
ted to the renal transplant program at the University of Minnesota Hospitals. There were 110 patients, all Caucasians, with a mean age of 35 years (range 23-48 years), 67 were males and 43 females. A more detailed clinical description of these patients has been published (Kjellstrand et al. 1973).
2. Living related donors to diabetic kidney recipients. Living related volunteer donors are frequently used at this institution. One or more of the recipients’ siblings and/or parents are not only tissue typed for HLA, but also admitted to the Clinical Research Center and studied for glucose tolerance. Eighty-eight volunteer potential kidney donors (mean age 40, range 18-46; 50 male, 38 female) have been studied. There were 61 siblings, 19 parents, and eight daughters, sons, nieces or nephews of the recipients. 3 . Non-diabetic kidney recipients and healthy controls. We have included HLA tissue typing of 165 subjects with non-diabetic nephropathy, transplanted contemporaneously with the diabetics, as well as a group of healthy controls (blood bank donors). All but two recipients, and all healthy controIs, were Caucasian. Methods
a) HLA typing. HLA antigens were determined with a standard two stage dye exclusion microcytotoxicity test (Amos et al. 1970), using a panel of 90 well-characterized antisera capable of detecting all defined HLA and most “W” specificities. Differences in HLA antigen frequencies between patients and controls were analyzed by chisquare analysis. P values were corrected for the number of specificities studied using the expression P = 1-(1-p)”, where p is the uncorrected value and the exponent the number of antigens studied. b) T h e kidney donors to diabetic relatives were given a 300 gram carbohydrate diet for
3 days before standard (OGT) and cortisolprimed (COGT) oral glucose tolerance tests were done as described before (Fajans & Conn 1954, Snegoski & Freier 1973). c) T h e average “relative risk’ for the presence of diabetes in individuals carrying a certain antigen was calculated using the expression fd (1-fc) fc (1-fd) where fd = frequency in diseased and fc frequency in controls.
Results Table 1 shows the frequencies of 22 HLA antigens in diabetic kidney transplant recipients (JODR), non-diabetic kidney recipients (NDR), and healthy controls. T h e incidence of HLA antigen A1 was significantly higher in diabetics than in healthy controls ( P = .02), whereas antigen B8 was significantly more frequent in diabetic than in non-diabetic kidney recipients (P = ,011) and healthy controls ( P = .011). There were no differences between male and female diabetics. T h e incidence of other antigens, including BW15, did not differ between the three groups. The average “relative risk” for the presence of diabetes with severe renal disease was increased 2.4 and 3.1 times in the individuals carrying HLA antigens A1 and B8 respectively. T h e volunteer potential donors to the diabetics were divided into Group I with both glucose tolerance tests normal (31 donors), Group I1 with normal OGT but abnormal COCT (29 donors), and Group 111 with both OGT and COGT abnormal (eight donors). Twenty donors had nondiagnostic tests (Group IV). Although there was a higher frequency of antigens A1 and B8 in Groups I and 11, it was not significantly different from controls, after correction of P values.
HLA AND DIABETIC MICROANGIOPATHY
Table 1 Frequency of HLA specificities i n diabetic (JODR) and non-diabetic kidney transplant recipients (NDR) and healthy controls (C)
HLA
J o D R (110)* NDR (165)*
%
c (217)*
%
%
Locus A A1 A2 A3 A9 A10 A1 1 A28 Awl9
47.3** 47.3 20.9 27.3 6.4 3.6 6.5 15.4
32.7 53.3 29.7 13.9 9.7 9.1 7.7 21.6
27.2 55.3 28.1 17.5 12.9 10.2 7.4 18.0
Locus B B5 B7 B8 B12 B13 B14 B18 B27 BWl5 BW16 BW17 BW22 BW35 BW40
10.9 13.6 45.5** 25.4 4.5 4.4 4.3 6.5 15.2 10.8 4.5 4.4 10.9 19.6
18.2 29.1 21.8 26.7 7.9 6.8 13.8 7.8 15.5 4.3 7.7
12.5 25.8 21.2 30.0 6.9 5.5 5.5 5.0 17.0 7.4 5.0
*
** ***
0.9
0.9
13.8 19.6
14.3 18.4
No. of subjects in each group. For W antigens there were only 46 subjects in JODR group and 116 in NDR group. P < .02 comparing JODR with C. P < ,011 comparing JODR with NDR and C.
There was an appreciably higher incidence of antigen B18 in non-diabetic recipients, which was significantly different from controls (P < .025), only before correction for the number of antigens; the relative risk for B18 in this group was 2.75.
Discussion Although the role of the genetic factor in the pathogenesis of diabetes is universally recognized, there is little agreement about the mode of genetic inheritance. Indeed, practi-
235
cally every genetic mechanism has been proposed (Rimoin 1971). Recently, a great deal of evidence has been marshalled in favor of genetic heterogeneity, i. e. several distinct disorders resulting from different gene mutations at several loci, and/or from different mutant alleles at the same locus, each of which includes carbohydrate intolerance (Rirnoin 1971), but are perhaps distinct from each other in important pathogenic and clinical aspects. Recent evidence has suggested that viral infections (Steinke & Taylor 1974) and autoimmunity (Lancet 1974) may have a pathogenic role in some cases of diabetes Reports of associations of HLA specificities B8 and BW15 with juvenile-onset, insulin-dependent diabetes (Singal & Blajchman 1973, Nerup et al. 1974, Cudworth & Woodrow 1975, Nelson et al. 1975), and a genetic linkage of HLA locus B with immune response genes (Blumenthal et al. 1974), has strengthened the autoimmune hypothesis of diabetes. Our finding of an association between HLA antigens A1 and B8, but not BW15, and diabetes with severe microangiopathy, adds a new dimension to genetic heterogeneity of diabetes. Particularly relevant to this association is the finding that among diabetic identical twins with early onset diabetes (< 40 years of age like most of our patients), only the concordant pairs showed a higher frequency of antigen B8 (Nelson et al. 1975). Clinical evidence indicated that the disease in concordant pairs was more prone to be complicated by proliferative retinopathy (Pyke & Tattersall 1973), than in the discordant pairs. The role of genetic versus metabolic determinants in the pathogenesis of diabetic microangiopathy is controversial. Siperstein et al. (1968) showed that 50% of the prediabetics (normal offspring of conjugal diabetic parents), and 98% of overtly diabetic patients had abnormally thickened
236
BARBOSA ET Al.
skeletal muscle capillary basement membrane, which suggests a major role of genetics in the pathogenesis of microangiopathy. However, others have not confirmed the capillary abnormality in prediabetics, and showed a correlation of the lesion with the duration of overt diabetes (Williamson et al. 197 I), suggesting a primary pathogenic role for the metabolic abnormality. T h e relationship of skeletal muscle basement membrane thickness with diabetic glomerulosclerosis has not been studied, but positive correlation with retinopathy has been reported (Yodaiken et al. 1975). Although similar renal vascular lesions such as hernochromatosis (Becker & Miller 1960) have been described in secondary diabetes, their incidence has usually been lower than in primary diabetes mellitus, as though there were genetic factors of considerable pathogenic importance in the latter, but not in the former. T h e association of HLA antigens A1 and B8, probably reflecting a high frequency o f haplotype Al-B8, with diabetes complicated by severe microangiopathy, supports the concept that juvenile onset diabetes (with microangiopathy) is one of the HLA-BSassociated autoimmune disorders. That antigen, as well as BW15, found in association with juvenile onset diabetes, seems to have useful prognostic significance. T h e study of HLA-I1 specificities in diabetes may further strengthen this concept. A high frequency of DW3 in juvenile onset diabetes has been claimed (Thomsen et al. 1975). T h e trend for a higher incidence of H1.A specificities A1 and B8 among related potential donors to kidney recipients may be due to either histocompatible donor selection, their relation to the diabetics, or the inclusion of subclinical diabetics in this group. There were no detectable differences for any of the antigens tested between donors in Group I (all tests for diabetes
normal), and Groups 11 to IV (at least one abnormal test), and there was a high concordance rate in donor-recipient pairs for antigen B8. T h e exclusion o f offspring, nieces and nephews, donors of diabetic recipients, did not change the results. Therefore, the increased incidence of that specificity among donors to diabetics is most likely due to histocompatible donor selection.
Acknowledgments
We are grateful to Ms. Jane Thompson for data compilation. Research was supported in part by: Bush Foundation, St. Paul, Mn., and U.S.P.H. Grants HL-06314, lROlHD08145, NIAID 72-54 Contract, and General Clinical Research Centers Program (RR-400), T h e Division o f Research Resources, N I H .
Rejerences Amos, D.H., Bashir, W., Boyle, W . , Macqueen,
M . E . & Tilikainen, A. (1970) A simple microcytotoxicity test. Transplantation 7, 220-223. Becker, D. & Miller, M. (1960) Presence of diaberic glomerulosclerosis in patients with hemochromatosis. New Engl. /. Med. 263, 367-374. Blumenthal, M.N.,Amos, D.B., Noreen, H . , Mendell, N . R . & Yunis, E.J. (1974) Genetic mapping of Ir locus in man: Linkage to second locus of HI.-A. Science 184,- 1301-1303. Cudworth, A.G. & Woodrow, J.C. (1975) HL-A system and diabetes mellitus. Diabetes 24, 345-349. Editorial (1974) Autoimmune diabetes mellitus. Lancet ii, 1.549-1550. Fajans. S.S. & Conn, J.W. (1954) Theapproach to the prediction of diabetes mellitus by modification of the glucose tolerance test with cortisone. Diabetes 3, 296-304. Kjellstrand, C.M., Simmons, R.L., Goetz, F.C., Buselmeier, T.J., Shideman. J.R., Hartitsch, B.V. & Najarian, J.S. (1973) Renal transplantation in patients with insulin dependent diabetes. Lancet ii, 4-8. Nelson, P.G., Pyke, D.A., Cudworth, A.G., Woodrow, T . C . & Batchelor, A. (1975) Histocompatibility antigens in diabetic identical twins. Lancet ii, 193-194.
HLA AND DIABETIC MICROANGIOPATHY
Nerup, J., Platz, P., Andersen, O.O., Christy, M., Lyngsoe, J., Poulsen, J. E., Ryder, L.P., Nielsen, L.S., Thomsen, M. & Svejgaard, A. (1974) HL-A antigens and diabetes mellitus. Lancet ii, 864-866. Pyke, D.A. & Tattersall, R.B. (1973) Diabetic retinopathy in identical twins. Diabetes 22, 6 13-6 18. Rimoin, D.L. (1971) Inheritance in diabetes mellitus. Med. Clin. N . Amer. 5 5 , 807-819. Singal, D.P. & Blajchman, M.A. (1973)Histocompatibility (HL-A) antigens, lymphocytotoxic antibodies and tissue antibodies in patients with diabetes mellitus. Diabetes 22, 428-432. Siperstein, M.D., Unger, R.H. & Madison, L.L. (1968) Studies of muscle capillary basement membrane in normal subjects, diabetics and pre-diabetics. J . clin. Invest. 47, 1973-1999. Snegoski, C.M. & Freier, E.F. (1973) Glucose determination by enzymatic method. Amer. J . Med. Technol. 39, 140-144. Steinke, J . &Taylor, K.W. (1974) Viruses and the etiology of diabetes. Diabetes 23, 631-633.
237
Thomsen, M., Platz, P., Andersen, O., Christy, M., Lyngs@e, J., Nerup, J., Rasmussen, K., Ryder L., Nielsen, L. & Svejgaard, A. (1975) MLC typing in juvenile diabetes mellitus and idiopathic Addison's disease. Transplanf. Rev. 22, 126-147. Williamson, J.R., Volger, N.J. & Kilo, C. (1971) Microvascular disease in diabetes. Med. Clin. N . Amer. 55, 847-860. Yodaiken, R.E., Menefee, M., Seftels H.C., Kew, M.C. & McClaren, M.J. (1975) Capillaries of South African diabetics. IV. Relation to retinopathy. Diabetes 24, 286-290.
Address: J. Barbosa, M.D. Dept. of Medicine University of Minnesota Medical School Minneapolis Minnesota 55455, U.S.A.
