Immunologic prognostic factors of renal allograft survival.

INTRODUCTION: Successful outcome of renal transplantation depends on various factors, of which immunologic is one of the most important. Accumulated experience of a single center, with the same surgical and immunological team contributes significantly to safe conclusions. Purpose of this study was the evaluation of potential factors, in particular immunologic, that influence renal allograft survival. PATIENTS AND METHODS: During the period 1991-2013, 20,784 surgical operations have been performed in our Department of Surgery - Transplant Unit, of which 575 were renal transplantations. We examined donor and recipient demographic factors, immunologic characteristics along with patient and graft survival. RESULTS: Renal allograft was retrieved from living-related donor in 103 cases and in 472 from cadaveric donor. Donor age was 46.7 ± 18.5 years old and 49.9% (287) were male. Recipient age was 48 ± 12.3 years old and 402 were male. HLA histocompatibility was carefully matched resulting in 85.5% renal transplants with 2-4 HLA mismatches and 93.8% renal transplants with at least one HLA-DR. Renal graft survival the first, fifth and tenth year was 89%, 76%, and 67% and patient survival was respectively 95%, 89% and 83%. Statistical analysis revealed that only donor age influenced renal graft survival (P < .05). HLA mismatches were not correlated with graft survival (log rank P = .495), but identification of panel reactive antibodies (PRA) class I and class II post transplantation had a statistically significant impact on long term renal graft survival (log rank P < .001 and P = .021, accordingly). CONCLUSIONS: Analysis of potential prognostic factor showed that only donor age was correlated with allograft survival. Development of PRA following renal transplantation influenced long term graft survival. Good HLA matching with at least one HLA DR resulted in excellent graft and patient survival.

HLA alleles as predisposal factors for postmenopausal osteoporosis in a Greek population.

It is well established that genetic factors play an important role in the pathogenesis of osteoporosis, a common condition characterized by reduced bone mass and increased fracture risk. The major histocompatibility complex in humans, known as human leukocyte antigen (HLA) region, is the most polymorphic human genetic system and it is known as a cluster of genetic markers, associated with several diseases. In order to evaluate the contribution of HLA alleles in bone mass loss, polymorphisms in the HLA class I (-A, -B and -Cw) and class II (-DR and -DQ) antigens were studied in 126 postmenopausal women of Greek origin. It was found that HLA-B7 (P= 0.069), -DR15 (P= 0.019) and -DQ6 (P= 0.026) were associated with a lower bone mineral density measured at the forearm. This study shows a significant association between HLA alleles and bone mass loss in the population studied.

Human leukocyte antigens as genetic markers in Greek patients with sporadic pancreatic cancer.

PURPOSE: In this study we investigated the relationship between specific HLA antigens and sporadic pancreatic cancer in Greek population. METHODS: The allele frequencies of serologically and molecular defined class I and II HLA antigens were studied in 60 unrelated patients with pancreatic cancer histologically confirmed. The results obtained for HLA frequencies were compared with those of 105 healthy control subjects (control group). RESULTS: Increased frequencies of HLA-A30 (16.7 vs. 3.8%; P < 0.01; OR = 5.05), A31 (9.5 vs. 1.9%; P < 0.05; OR = 5.72), B18 (31.7 vs. 14.3%; P < 0.05; OR = 2.78) and Cw7 (53.3 vs. 21.9%; P < 0.01; OR = 4.07) were observed in patients with pancreatic cancer in comparison to the control subjects. CONCLUSIONS: This study demonstrates the association between specific HLA antigens and pancreatic cancer development in whites and suggests a genetic susceptibility factor for the disease.

Association of vitamin D receptor gene polymorphisms with bone mineral density in postmenopausal women of Hellenic origin.

OBJECTIVES: There are numerous indications that genetic factors play an important role in the pathogenesis of osteoporosis, a common condition characterized by reduced bone mass and increased fracture risk. The vitamin D receptor (VDR) gene has been suggested as a possible candidate gene for the regulation of bone mass but the relationship between VDR polymorphisms and bone mineral density (BMD) is controversial and has not been confirmed by all workers in different ethnic groups studied. METHODS: In order to evaluate the contribution of the VDR alleles in bone mass loss, the BsmI, ApaI and TaqI polymorphisms in the VDR gene were studied in 126 postmenopausal women. RESULTS: It was found that the bb, aa and TT genotypes and the bAT and baT haplotypes were associated with a lower BMD measured at the forearm. CONCLUSIONS: Our analysis reveals a significant association between VDR gene alleles and bone mass in the population studied.

HLA phenotypes as promoters of cardiovascular remodelling in subjects with arterial hypertension.

The objective of this study was to investigate the association between human leukocyte antigens (HLA) phenotypes and cardiovascular remodelling, as expressed by left ventricular mass (LVM) and carotid intima-media thickness (IMT), in hypertensives. We examined 153 subjects with arterial hypertension and 61 normotensive controls living in the greater Athens area. The population was classified into three groups and specifically group I (normotensives), group II with Grade 1 hypertension and group III with Grade 2 or 3 hypertension. HLA class I and class II antigens were studied by microlymphocytotoxic technique. Carotid IMT and LVM were determined by ultrasonography. The prevalence of HLA DQ7 in the hypertensive cohort was 27.4% that was significantly smaller than the 52.5% among the controls (P = 0.002). The HLA DR11 was found in 24.0% of the hypertensives and in 52.5% of the controls (P < 0.001). Group III hypertensives with HLA DR11 exhibited significantly higher LVM/h in comparison to the hypertensives without this HLA (199.0 +/- 28.8 vs 171.2+44.1g/m, P = 0.009). This association was not present in groups I and II. Similarly, group III hypertensives with HLA DQ7 were characterized by higher IMT in comparison to those without this HLA (0.94 +/- 0.19 vs 0.83 +/- 0.23 mm, P = 0.048). HLA DR17 was associated with higher IMT in both groups II and III (1.00 +/- 0.19 vs 0.82 +/- 0.19 mm, P = 0.046 and 1.01 +/- 0.23 vs 0.84 +/- 0.22 mm, P = 0.049, respectively) but not in group I. In conclusion, certain HLA phenotypes may be related to the levels of arterial blood pressure. Moreover, it seems that these HLA phenotypes may identify subjects with arterial hypertension that are more prone to develop cardiovascular hypertrophy.

Atherosclerosis of carotid arteries and the ace insertion/deletion polymorphism in subjects with diabetes mellitus type 2.

BACKGROUND: The aim of the present study was to investigate the association of the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism with the ultrasonographically evaluated severity and characteristics of carotid artery atherosclerosis in subjects with diabetes mellitus type 2. METHODS: We assessed 184 subjects with diabetes mellitus type 2, 75 males and 109 females, mean age 61.4+/-7.7 years. All subjects were receiving oral antidiabetic drugs for glycemic control and were free of cardiovascular events. The ACE genotype was analyzed by the polymerase chain reaction (PCR) technique. The ultrasonographic examination of the carotid arteries was performed in both B-mode imaging and Doppler ultrasound. The common carotid artery intima-media thickness was assessed 15-20 mm proximal to the dilatation of the carotid bulb. The atheromatous lesions were classified according to their echogenic characteristics as predominantly echolucent, mixed and predominantly echogenic with under 30, 30-70 and over 70% of the total plaque area echogenicity, respectively. RESULTS: From the total cohort 29 (15.8%) subjects had the II, 86 (46.7%) the ID and 69 (37.5%) the DD ACE genotypes. The mean carotid artery diameter stenosis was 37+/-17%, 43+/-19% and 40+/-20% (p=NS) and the intima media thickness was 0.94+/-0.24 mm, 0.97+/-0.20 mm and 0.98+/-0.20 mm (p=NS) in the II, ID and DD subgroups, respectively. When the echogenicity was analyzed according to the ACE I/D polymorphism, 12 subjects (41.4%), 13 (44.8%) and 4 (13.8%) with II genotype had predominantly echogenic, mixed and predominantly echolucent lesions, respectively. The ID genotype diabetics were found to have predominantly echogenic plaques in 41 cases (47.7%), mixed in 30 (34.9%) and predominantly echolucent in 15 cases (17.4%). From the 69 DD subjects 19 (27.5%) had predominantly echogenic plaques, 26 (37.7%) had mixed and 24 (34.8%) had predominantly echolucent lesions. Predominantly echolucent plaques were more frequently encountered among diabetics with the DD genotype (p<0.05), even after correction for demographic characteristics, the main risk factors of atherosclerosis and blood glucose control. CONCLUSIONS: The ACE genotype seems to be associated with the echogenicity of carotid artery atheromatosis but not with the common carotid artery intima media thickness or the degree of internal carotid artery stenosis in subjects with type 2 diabetes mellitus. The DD genotype may be implicated in the increased cardiovascular risk that characterizes echolucent plaques.

Association of the HLA antigens with early atheromatosis in subjects with type 2 diabetes mellitus.

BACKGROUND: Inflammation plays an important role in the pathogenesis of atherosclerosis. The major histocompatibility complex, as expressed by the human leukocyte antigens (HLA) is considered to regulate the immune response. The aim of this study was to investigate the association of the HLA antigens with vascular remodeling estimated by the carotid intima-media thickness (IMT) in subjects with type 2 diabetes mellitus (DM). METHODS: We evaluated 197 patients with type 2 DM, 80 males and 117 females, mean age 61.8+/-7.8 years, with no history of cardiovascular events. The presence of other major cardiovascular risk factors was recorded. The currently identified HLA class I (-A, -B, -Cw) and class II (DR, -DQ) antigens were studied by a classical 2 step microlymphocytotoxic technique in peripheral blood T and B lymphocytes. Measurements of the IMT were performed in the right and left common carotid arteries, 15-20 mm proximal to the dilatation of the carotid bulb in an end-diastolic "frozen" and magnified B-mode ultrasonographic image. Glycosylated hemoglobin A1c (HbA1c) and C-reactive protein (CRP) were also measured. The results are presented as mean +/-1 standard deviation. RESULTS: Regarding the HLA phenotypes in the final analysis we tested a total of 24 HLA antigens that exhibited a frequency of at least 5% in our diabetic population. Only HLA A3 was found to be significantly associated with the carotid IMT. Forty-nine (24.9%) diabetics were HLA A3 positive (group A), while 148 (75.1%) were HLA A3 negative (group B) and had mean IMT of 0.89+/-0.16 mm and 0.98+/-0.21 mm, respectively (p<0.01). Also the two groups differed significantly in respect to CRP, with group A exhibiting lower serum levels (1.1+/-0.4 mg/dl vs 2.6+/-0.7 mg/dl for group A and B, respectively, p<0.05). However, no differences were observed between the two groups as far as blood glucose control, arterial hypertension and dyslipidaemia were concerned. CONCLUSIONS: Human leukocyte antigen A3 is associated with less vascular damage, as expressed by carotid wall thickness, in subjects with type 2 DM. These subjects may be characterized by a milder inflammatory response, as shown by the lower serum levels of CRP.

Association of specific HLA phenotypes with left ventricular mass and carotid intima-media thickness in hypertensives.

The aim of this study was to investigate the hypothesis that the expression of certain HLA antigens may constitute a risk marker for cardiovascular hypertrophy in subjects with arterial hypertension. We examined 158 subjects with newly diagnosed arterial hypertension. HLA class I (-A, -B, -Cw) and class II (-DR, -DQ) antigens were studied by two-step microlymphocytotoxic technique in peripheral T and B lymphocytes. Carotid intima-media thickness (IMT) was determined noninvasively by ultrasonography. The left ventricular mass was calculated according to the formula of Devereux and was normalized by the individual's height (LVM/h). The individuals with DR13 and DR17 were characterized by higher values of IMT compared to those without these HLA (0.096+/-0.018 cm v 0.085+/-0.021 cm, P = .011, 0.100+/-0.019 cm v 0.084+/-0.021 cm, P = .012, respectively). The presence of HLA DQ7 was characterized by markedly higher values of IMT that just failed to reach statistical significance (0.091+/-0.019 cm v 0.084+/-0.022 cm, P = .045). Furthermore, subjects with HLA DQ7 and DR11 exhibited higher values of LVM/h in comparison to those without these HLA (191.3+/-36.2 g/m v 166.9+/-41.0 g/m, P = .029 and 194.6+/-34.3 g/m v 166.6+/-40.9 g/m, P = .034, respectively). Hypertensive subjects with HLA B51 tended to have lower LVM/h (166.6+/-39.0 g/m with v 176.0+/-41.7 g/m without HLA B51, P = .045). In conclusion, it can be postulated that certain HLA phenotypes exhibit an association with increased carotid IMT and left ventricular mass in hypertensive subjects. The determination of these antigens may help to identify subjects at high risk for cardiovascular events.

TCRgammadelta + T lymphocytes in unexplained recurrent spontaneous abortions.

PROBLEM: It is generally accepted that the immune system and cellular immunity in particular are involved in the mechanisms affecting the outcome of gestation. In order to evaluate a putative role of lymphocytes in the immunological mechanisms of unexplained recurrent spontaneous abortions (URSA), we studied peripheral blood lymphocyte subpopulations in 244 women with URSA and 44 controls. METHOD OF STUDY: Direct immunofluorescence in whole blood with the appropriate combinations of monoclonal antibodies and flow cytometry was used. RESULTS: The study showed: a) a statistically significant increase of the mean CD4/CD8 ratio (2.12+/-0.84 vs 1.85+/-0.63, P = 0,039); b) a statistically significant decrease of the mean value of the percentage of CD5+ CD19+ lymphocytes (0.4+/-0.6 vs 1.4+/-0.78, P < 0.0001); and c) a statistically significant increase of the percentage of T lymphocytes expressing TCRgammadelta (4.68+/-3.19 vs 2.61+/-1.14, P < 0.0001). It should be noted that a statistically significant high number of women with URSA (72/195, 36.9%) showed an increased percentage of TCRgammadelta T cells (> or = 5%, where 5 equals the mean value + 2 standard deviations (SD) of the mean value of controls), whereas such a high percentage was not found in any control subject. CONCLUSIONS: It seems that women who experienced URSA comprise a heterogeneous population, as far as immunological parameters are concerned. At least in a subgroup of them, TCRgammadelta + T cells could be considered to play a role in the immune pathogenesis of fetal loss.

Thyroid autoimmunity in patients with recurrent spontaneous miscarriages.

Recurrent spontaneous miscarriage (RSM) is a multifactorial problem. Auto- and alloimmune parameters have been implicated. Antithyroid antibodies (ATA) were tested in a group of women with RSM. The presence of antipaternal antibodies (APCA) was evaluated as an index of alloimmune contribution. Thirty euthyroid women with RSM (three or more consecutive miscarriages) aged 25-37 years were compared with 15 matched controls. Thyroid peroxidase (TPO) and thyroglobulin antibodies were tested with a chemiluminescence immunoassay and APCA were tested with a cross-match reaction. Results were compared using the chi-squared test. There was a higher frequency of ATA in women with RSM compared to controls (37% versus 13%, p < 0.05). Twenty of the women (67%) with RSM were tested negative for APCA, indicating an alloimmune contribution to their infertility. In this subgroup of women, the frequency of ATA continued to be higher than controls (40% versus 13%, p < 0.05). In conclusion, women with RSM, independent of APCA status, have a higher frequency of ATA. This may represent an additional marker for impaired regulation of the maternal immune system.

Distribution of different HLA antigens in Greek hypertensives according to the angiotensin-converting enzyme genotype.

The angiotensin-converting enzyme (ACE) insertion/deletion polymorphism is an independent risk factor for cardiovascular disease. It has also been suggested that some HLA genes may contribute to the genetic susceptibility to essential hypertension. So far, an association between ACE polymorphism and HLA antigens in arterial hypertension has not been reported. We have studied 94 subjects with newly diagnosed essential hypertension, 49 men and 45 women (mean age, 52.3 +/- 11.3 years), as well as 104 randomly selected, age- and gender-matched normotensive individuals (54 men and 50 women, mean age 48.7 +/- 10.8 years). Both cohorts originated from the Greek population and lived in the greater Athens area. The ACE genotype was analyzed by polymerase chain reaction. HLA class I and II antigens were studied by serologic and molecular techniques. The prevalence of the ACE genotypes did not differ significantly between hypertensives and normal individuals. The casual blood pressure levels and the average ambulatory blood pressure levels were similar among the three ACE genotypes. Hypertensives with the ACE-DD genotype were characterized by an increased prevalence of the HLA-A2 antigen (50% v 31.4%, P < .005) and DR6 (16.7% v 11.4%, P < .01) in comparison to the normotensive subjects with the ACE-DD genotype. HLA-A24 was found more frequently among the hypertensives with the ACE-ID genotype than in the normal controls with the same genotype (35.5% v 26.4%, P < .05). ACE-DD genotype is associated with a high prevalence of specific HLA antigens. The coexistence of the ACE-DD genotype with certain HLA phenotypes could reveal a distinct hypertensive population with increased risk for cardiovascular events.

Human leukocyte antigens as genetic markers in colorectal carcinoma.

PURPOSE: Similar to findings obtained for most carcinomas, the pathogenesis of colorectal cancer is considered to be multifactorial. There is strong evidence for an inherited, genetic predisposition to disease in patients with familial adenomatous polyposis and hereditary nonpolyposis colorectal cancer. There is still debate, however, about the contribution of genetic factors to the pathogenesis of sporadic colorectal cancer. The present study was undertaken to search for human leukocyte antigen associations in a group of patients with colorectal cancer and to correlate the findings with both the histology of the disease and family history. SUBJECTS AND METHODS: The allele frequencies of serologically defined human leukocyte antigen class I and II antigens were studied in 101 patients with a recent, histologically confirmed diagnosis of colorectal cancer. All individuals in this study were unrelated to each other. After surgical treatment, all patients were grouped according to the stage (Dukes Stages A, B, C, and D), differentiation (Grades 1, 2, and 3), and the site of the tumor. Patients were also classified with regard to family history for colorectal cancer. The results obtained for human leukocyte antigen frequencies were compared with those of 105 healthy control subjects (control group). RESULTS: An increased frequency of human leukocyte antigen-B18 (27.72 vs. 14.28 percent; P < 0.025; odds ratio = 2.3) and of human leukocyte antigen-DQ5 (43.56 vs. 22.5 percent; P < 0.01; odds ratio = 2.65) was observed for patients with colorectal cancer vs. control subjects, respectively. In addition, human leukocyte antigen-B18 was present with increased frequency (30.76 percent; P < 0.05; odds ratio = 2.66; and 26.67 percent; P < 0.05; odds ratio = 2.18) among patients with rectal and colon carcinoma, respectively. A higher frequency of human leukocyte antigen-DQ5 (45.33 percent; P < 0.01; odds ratio = 2.84) was observed among patients with colon carcinoma. Remarkably, human leukocyte antigen-DQ5 (50 vs. 22.5 percent; P < 0.05; odds ratio = 3.43) and human leukocyte antigen-A1 (41.66 vs. 12.38 percent; P < 0.01; odds ratio = 5.05) were found to be strongly associated with a family history of colorectal cancer. CONCLUSION: The observation of specific human leukocyte antigen associations with particular subsets of colorectal cancer strongly suggests that genetic susceptibility for the development of colorectal cancer exists. Although the multifactorial pathogenesis of colorectal cancer must be considered, human leukocyte antigens may have useful predictive and diagnostic value.

HLA-TNF haplotype heterogeneity in Greek SLE patients.

OBJECTIVE: To examine TNF microsatellite allele frequencies in SLE patients in the Greek population, where disease susceptibility is less associated with HLA-DR3 haplotypes. METHODS: A cohort of 46 Greek SLE patients were investigated. Allele frequencies for the TNF microsatellite markers a, b, c and d were determined using a fluorescence based DNA fragment sizing technique. HLA class II typing was performed using a molecular based technique. RESULTS: Associations between SLE and DRB1*1501, *1601 and *0701 were observed and DRB1*0301 was only marginally increased in patients. Linkage disequilibrium was found between DRB1*1501 and TNF a11 and also for DR3 and TNF a2, b3, d2. Stratification of patients suggested that DRB*1501 and TNF a11 frequencies were higher in SLE patients with renal disease and TNF a2 and b 3 frequencies in those without, although these differences did not reach statistical significance. CONCLUSIONS: SLE in this Greek population appears to be associated with a number of HLA-DRB1 alleles. The development of renal complications in these patients may be related to the TNF polymorphism encoded on these HLA haplotypes.

HLA antigens in microscopic polyarteritis (MP) with renal involvement.

Serological HLA-A, B, C, DR and DQ typing was performed in 23 patients with microscopic polyarteritis and renal involvement and in 405 healthy individuals, all of Greek origin. An increased frequency of HLA-A26 (26% vs. 11.3%, x2 = 4.423, p < 0.05) and HLA-A11 (26% vs. 9.6%, x2 = 6.825, P < 0.02), and a decreased frequency of HLA-DR3 (4.3% vs. 24.1%, x2 = 5.935, p < 0.025) were found. Five out of six patients, who did not respond to treatment possessed HLA-DR5. These observations suggest that HLA gene products may influence the clinical expression, as well as the outcome of this disease.

Increased frequency of HLA B17 antigen in girls with Turner syndrome and their fathers.

HLA-A, -B and -DR antigen distribution was studied in 49 girls with Turner Syndrome (TS), in 43 of their parents, as well as in 433 controls. No increased frequency of DR3, DR4 was found in our group. However, an increased frequency of HLA B17 antigen was disclosed (18.3% in TS versus 6.4% in the controls, p < 0.001 and pc < 0.01). Furthermore, the HLA B17 antigen was of paternal origin in 77.7% of the cases. The interpretation of the present findings is quite difficult. Most likely, the findings are related to the chromosomal abnormality rather than to autoimmunity. It is quite possible that genes within the region of class I genes create unfavorable circumstances leading to the loss of the sex chromosome or, alternatively, genes in this region confer protection and prevent miscarriage of the affected fetus.