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ABSTRACT: HLA class I molecules are frequently lost in a large variety of human carcinomas, possibly because of T-cell immune selection of major histocompatibility complex class I deficient tumor variants. We report that this phenomenon is also a frequent event in bladder carcinomas. Of a total of 72 bladder carcinomas, 72% of the tumors had at least one alteration in HLA class I expression. These altered HLA class I phenotypes were classified as total HLA class I loss (25%; phenotype I); HLA-A or/and HLA-B locus-specific loss (12%; phenotype III); and HLA class I allelic loss (35%; phenotype II or IV). Comparison of histopathological parameters with HLA class I expression showed a statistically significant relationship with the degree of differentiation and tumor recurrence.
Tissue Antigens 11/2003; 62(4):324-7. · 2.59 Impact Factor
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ABSTRACT: HLA class I molecules are frequently lost in a large variety of human carcinomas, possibly because of T-cell immune selection of major histocompatibility complex class I deficient tumor variants. We report that this phenomenon is also a frequent event in bladder carcinomas. Of a total of 72 bladder carcinomas, 72% of the tumors had at least one alteration in HLA class I expression. These altered HLA class I phenotypes were classified as total HLA class I loss (25%; phenotype I); HLA-A or/and HLA-B locus-specific loss (12%; phenotype III); and HLA class I allelic loss (35%; phenotype II or IV). Comparison of histopathological parameters with HLA class I expression showed a statistically significant relationship with the degree of differentiation and tumor recurrence.
Tissue Antigens 09/2003; 62(4):324 - 327. · 2.59 Impact Factor
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ABSTRACT: We have studied the allele distribution of DRB1, DQB1 and DPB1 loci in 80 unrelated Gypsies living in different eastern areas of the Andalusian province of Granada (southern Spain). The frequency distribution of HLA class II alleles and the genetic distance of Andalusian Gypsies from several Caucasian populations indicate a marked similarity - but not total - of the former with the Gypsy population previously studied in Madrid (central Spain), which suggests that both groups migrated together out of India. In terms of genetic distance, both Gypsy groups are more like the Czech Gypsies and the Northern Indian groups than their neighbouring Caucasian non-Gypsy populations. In summary our data support the hypothesis of a common anthropological origin of all three European Gypsy groups, which probably split up after their arrival in Europe.
Tissue Antigens 03/2001; 57(2):138-43. · 2.59 Impact Factor
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ABSTRACT: The exact frequency of HLA class I losses in human tumors is unknown. We have previously shown that primary breast and colorectal carcinomas frequently lose HLA class I molecules (88% and 73%, respectively). Now we report that this phenomenon is also a frequent event in laryngeal carcinomas. Of a total of 76 laryngeal carcinomas analyzed, 66% of the tumors showed an alteration in HLA class I phenotype. These altered HLA phenotypes were classified as total HLA loss (10.52%) (phenotype I); HLA-A locus-specific loss (13.15%) (phenotype IIIa); HLA-B locus-specific loss (10.52%) (phenotype IIIb); HLA allelic loss (27.63%) (phenotype IV); and HLA-A and B locus loss (3.9%). Comparison of histopathological parameters with HLA expression showed that poorly differentiated tumors had the lowest levels of HLA class I expression (p < 0.05).
Human Immunology 05/2000; 61(5):499-506. · 2.84 Impact Factor
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ABSTRACT: We studied 105 tumor samples obtained from patients diagnosed as having breast carcinomas for HLA class I and II (DR) antigen expression, using a panel of mAbs defining HLA-monomorphic, locus-specific and allele-specific determinants. Peripheral blood lymphocytes from patients were also typed for HLA alleles. The results indicated total HLA class I losses in 55 patients (52.3%), HLA-A locus losses in four patients (3.8%), HLA-B locus losses in eight patients (7.6%), and A, B, locus losses in 10 patients (9.5%). The remaining 28 patients whose tissues reacted positively with monomorphic- and locus-specific mAbs were tested for HLA allelic losses using several anti-HLA mAbs defining A2, A3, A9, B8, B12, etc. Of these 28 patients, 16 (57%) showed one or more losses of HLA reactivity. These results indicated that in 88.5% of patients we detected a particular HLA-altered tumor phenotype. The downregulation of HLA class I antigens in breast carcinomas may thus be more frequent than previously reported, and patients without HLA class I downregulation may be the exception rather than the rule. It cannot be ruled out that HLA alterations are present in some of the 12 patients with an apparently normal HLA phenotype, as some HLA alleles could not be studied because of the lack of appropriate mAbs. These HLA alterations could represent an important step associated with tumor invasion, conferring to the tumor cells the ability to escape from T-lymphocyte recognition.
Human Immunology 11/1996; 50(2):127-34. · 2.84 Impact Factor
