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Biomedical subjects

M Martinetti

Publications and source records attributed to M Martinetti.

At least 73 records · Page 4Linked to original sources
PubMed1992

Autoimmunity in vitiligo: relationship with HLA, Gm and Km polymorphisms.

Eighty-six patients affected by vitiligo were investigated for Gm, and Km polymorphisms, HLA markers and the presence of organ and non organ-specific autoantibodies. Vitiligo patients had an increased frequency of autoantibodies (71%), in particular anti-parietal cells (26.6%), antithyroglobulin (24.4%) and antithyroid microsomal antibodies (43%). One patient was also affected by Hashimoto's thyroiditis, 4 by Graves' disease and two others by nontoxic, multinodular goiter. No correlation was found between chronologic age and sex and the presence of autoantibodies, while an increased frequency of organ-specific autoantibodies was found with longer duration of vitiligo. HLA-A3 and Gm (3; 23; 5, 10, 11, 13, 14) phenotype frequencies were significantly increased in patients without autoantibodies (P less than 0.05). Patients negative for these two phenotypes were significantly more prone to develop autoantibodies than those positive (P = 0.0032). C4AQO allele showed a significantly decreased frequency in the whole group of patients when compared to the controls (P less than 0.05).

Adolescent↗
PubMed1992

[HLA polymorphism in the susceptibility or resistance to dilated cardiomyopathy].

Much of the surrounding studies on the association between HLA and diseases reflects a new insight into the key role of HLA molecules in the generation and regulation of the immune response. HLA molecules, on the surface of antigen presenting cells, bind foreign peptides. This HLA-antigen complex is then recognized by T lymphocytes and triggers the alloresponse against the peptide. Since many diseases associated with peculiar HLA antigens are thought to be autoimmune, the idea that certain Major Histocompatibility Complex (MHC) molecules could form complexes with self-peptides in anomalous ways, leading to an autoimmune reaction, is particularly attractive. Recent advances in molecular technology, x-ray crystallography and DNA studies have allowed the determination of the three-dimensional structure of some HLA class I and II molecules and also the amino acid sequences involved in binding of antigen fragments. This new information has prompted a search for differences, at the amino acid level, between HLA alleles previously shown to be positively or negatively associated with a pathology. Our own experience on the immunogenetic aspect of dilated cardiomyopathy (DCM) allowed us to assess some predisposing (HLA-DR4, DR5, C4A4) and protective (HLA-DR3) factors for DCM. Clinical heterogeneity also seems to imply a peculiar genetic background. The actual research is addressed to the study of the antigen binding site sequences and to the consideration of other new loci such as those entrapped within the HLA class III subregion (HSP70) and those lying within the class II region (PSF).

Cardiomyopathy, Dilated↗
PubMed1991

Age of onset in vitiligo: relationship with HLA supratypes.

HLA class I (A, B, C), class II (DR, DQ) histoglobulins and HLA class III (C4A, C4B and Bf) complement factors were analysed in 87 patients with vitiligo and in controls. Two HLA supratypes seem to mark different age of onset of vitiligo: HLA-BfS, C4A3, C4B1, DR5 (W11), DQW3 is characteristic of the pediatric form; while HLA-BfS, C4A3, C4B1, DR7, DQW2 marks the adult form of disease. The importance of defining HLA supratype, not single alleles, is discussed.

Adolescent↗
PubMed1991

Hypersomnia in dystrophia myotonica: a neurophysiological and immunogenetic study.

Ten patients with dystrophia myotonica (8 adults and 2 prepubertal children), from three unrelated families, were investigated for diurnal sleepiness, using a sleep questionnaire and multiple sleep latency test (MSLT). Immunogenetic study was also carried out to assess the involvement of HLA region genes in modulating susceptibility to excessive diurnal sleepiness (EDS). EDS was reported by 5 patients and confirmed in each case by MSLT. In the whole patients group, mean daytime sleep latency was significantly shorter than in healthy controls matched for age and sex. At clinical or neurophysiological evaluation, EDS did not show the features associated with the narcoleptic type. In only one case hypersomnolence could be explained by underlying sleep-disordered breathing. HLA patterns were different from those frequently observed in the narcoleptic or non-narcoleptic types of hypersomnia. In patients with EDS, the frequency of the DQW1 and particularly of the DRW6-DQW1 haplotype appeared to be over-represented.

Adult↗
PubMed1991

Sarcoidosis and major histocompatibility complex genes with special emphasis on BF F subtypes.

Frequencies for HLA class I and II histoglobulins and C4A, C4B, BF complement proteins were performed for 59 sarcoidosis patients. The DR5 allele was present in 55.9% of patients as compared to 31.5% of controls. We noticed that its increase was more relevant in males and in those with a poor prognosis. BF F allele was significantly over-represented in patients (29.09% vs. 19.15% of control), especially in women. Special emphasis was given to BF F subtyping, to define an association between a particular BF F subtype and patient's sex or disease outcome.

Alleles↗
PubMed1991

[Cost of the surgical treatment of inguinal hernias].

The hospital stay of 100 patients admitted to hospital in 1988 for surgical repair of inguinal and crural hernias was analysed. Fifty-three per cent of patients were over the age of 60 years and more than one half of them has a medical history. There was no mortality and only a single serious complication. The mean hospital stay was 7.6 days, influenced by the age of the patients. The complementary investigations only constituted a small proportion of the cost of the hospital stay. The authors conclude on the necessity for further reduce the length of hospital stay (principal cost factor) and even propose day admission, although this alternative can only be proposed to a minority of patients.

Adult↗
PubMed1990

Excess of HLA parental sharing in families with Turner patients.

In utero selection processes are probably related to mother-father compatibility as has been reported in abortion-prone couples and in Down syndrome studies. In order to analyse this phenomenon, we investigated families with chromosomal imbalance (Turner syndrome). We chose this model because previous data indicated a high frequency of HLA-A31 and B38 in Turner patients and in their mothers. We report high HLA antigen sharing in Turner families and great histocompatibility between mother and affected daughter, not related to abortion histories. The proportion of HLA-A homozygous cases among Turner children was higher than expected. The level of lymphocytotoxic antibodies against fetus in mothers of Turner patients was comparable to that of mothers of families with normal fertility and probably favoured these pregnancies.

Abortion, Habitual↗
PubMed1990

The effect of parental and maternal-fetal histocompatibility at MHC on sex ratio in offspring.

The secondary sex ratio (male births of total births) variation was investigated as a function of MHC antigens. Previous studies have indicated that at conception male zygotes are more frequent than female ones and abortions of male fetuses prevail. The present investigation addresses the question whether the histocompatibility relationships either between parents or between mother and offsprings may favor or hinder the outcome of pregnancy: particular combinations may cause distortions in the sex ratio. The results of the analysis of a sample of fertile families, demonstrate that, in first parities, female births are favored when parents share antigens at both HLA-A and -B loci (S.R. = 0.389), and mothers and fetuses share antigens at the HLA-B locus (S.R. = 0.222). The lack of antigens shared by parents at the three loci HLA-A, -B and -DR increases first male births (S.R. = 0.696). In the case of fetal maternal histocompatibility at DR locus only a slight, non-significant, increase in male first births (S.R. = 0.667) was observed. The effect of histocompatibility at HLA-B locus alone requires further investigation in order to assess the possible selective effect against male histocompatible embryos.

Embryo, Mammalian↗
PubMed1990

Familial elevation of serum angiotensin converting enzyme activity.

A clustering of high levels of serum angiotensin converting enzyme (S-ACE) was found in an Italian family. The elevation affected five subjects, two of whom were completely healthy and free from known causes of S-ACE increase. The values of S-ACE in hyperACEmic subjects exceeded the values found in normal relatives severalfold. HyperACEmia seemed to be inherited as an autosomal dominant trait. Immunogenetic studies were performed, but we did not find a genetic marker for this condition. The S-ACE activity was inhibited in vitro by edetic acid (EDTA) and SQ 14,225 (captopril). The S-ACE activity was also determined after 1:8 dilution and dialysis against saline of sera. From these experiments we deduced that Lieberman's intrinsic ACE inhibitor was lacking in the hyperACEmic sera. In the presence of remarkable S-ACE increase, a congenital elevation of S-ACE should be considered and it would be useful to perform a familial investigation.

Female↗
PubMed1990

[Pyknodysostosis. An unusual form of osteopetrosis].

The case reported here illustrates a rare variety of hereditary osteodysplasia, the pyknodysostosis. The patient, a 34-years-old man, had an history of prior fractures. He took medical advice for a mandibular osteitis consecutive to a tooth extraction. The clinical examination detected a dwarfism accompanied by cranial deformities and abbreviated terminal phalanges of the fingers. The histological study was performed on the mandibular sequestrum and on the adjacent bone. Besides of chronic osteitis, it exhibited an intense osteo-condensation with changes in collagen frame by polarized lumen. As to the 2 molars implanted in the sequestrum, they were ankylosed because of the loss of periodontal ligament. About this case, the differential diagnosis with osteopetrosis and cleidocranial dysostosis and the pathogenesis of the disease are discussed.

Adult↗
PubMed1989

The morphologic spectrum of dilated cardiomyopathy and its relation to immune-response genes.

Endomyocardial biopsies from 174 patients with dilated cardiomyopathy (DC) were examined. Eight patients with histologically proven myocarditis were excluded from the study. A peculiar pattern of oversized and bizarre nuclei was observed in only some of the remaining patients. Two groups were identified: those with and without this feature (groups A and B, respectively). Myocyte width, nuclear diameter and nuclear/sarcoplasmic ratio were significantly higher in group A. The mean respective values were 36 +/- 5 mu, 14 +/- 3 mu and 0.41 +/- 0.08 for group A versus 20 +/- 8 mu, 7 +/- 2 mu and 0.37 +/- 0.08 for group B. Interstitial fibrosis was similarly present in groups A and B. Endocardial thickness was significantly increased in all patients, with group A showing the highest mean value. The morphologic features showed no correlation with the clinical condition of the patients at time of presentation. HLA typing was performed in 50 consecutive patients, 38 from group A and 12 from group B. DR4 and DR5 antigens were significantly more frequent in DC patients than in a normal population control (400 blood donors), while DR3 was less frequent. Group A was more strongly associated with the DR5 antigen than group B (55.3 vs 25.0%, respectively). It was less strongly associated with the DR4 antigen compared with group B (21.5 vs 41.7%, respectively). No difference was observed between the 2 groups concerning negative association with the DR3 antigen. Endomyocardial biopsies from DC patients reveal marked morphologic changes from patient to patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Immunoglobulin allotypes in familial malignant melanoma.

There is some evidence that genes at loci on the lower end of chromosome 14, encoding for the immunoglobulin heavy chains allotypes (Gm), may influence susceptibility to human tumors. We examined the Gm and Km (IgK light chain) allotype distribution in a sample of 41 patients with familial malignant melanoma and in 79 healthy relatives. An increased frequency of the haplotype carrying the Gm (2) allotype, namely Gm (1, 2, 17;..;21), seemed to be peculiar to patients, since it was almost twice as frequent in them than in the healthy population and four times as frequent with respect to the healthy relatives. Our findings are in keeping with previous suggestions that in Caucasian melanoma patients genes of the immunoglobulin heavy chain constant region, or Gm-linked genes, may enhance susceptibility to malignant melanoma.

Female↗
PubMed1989

Familial steatocystoma multiplex: HLA, Gm, Km genotyping and chromosomal analysis in two unrelated families.

Steatocystoma Multiplex (S.M.) is an inherited condition characterized by the appearance of cysts during the first or second decade of life. Familial cases have occasionally been reported. We studied 13 patients affected by S.M. from two unrelated families, focusing our attention on HLA, Gm and Km genotypes and on chromosomal analyses. Although we failed to correlate the syndrome with a particular HLA, Gm or Km haplotype, we report some peculiarities and differences between these two families and the healthy Italian population.

Epidermal Cyst↗
PubMed1989

Recurrent extended HLA haplotypes in children with selective IgA deficiency.

HLA supratypes as well as serum IgG, IgA and IgM levels were determined in 44 children and adolescents with severe IgA deficiency (serum IgA less than 5 mg/dl) and in first degree relatives. Frequencies of the HLA alleles B14, DR1, DQW1, C4A2 and C4B2 were significantly higher in the IgA-deficient patients than in the controls. The most recurrent haplotype among patients was B14, DR1 (p less than 10(-4) preferentially associated with A33, A28 or A blank. The supratype B14, Bfs, C4A2, C4B2, DR1, DQW1 was present in a 14-fold higher frequency than in the controls, and strongly suggests the presence of a gene in the HLA region involved in the deficiency of IgA. The fact that this supratype was not always associated with IgA deficiency in the parents and that not all IgA-deficient subjects had this supratype is discussed. Severe IgA deficiency was found in four mothers (two of the four mother-child pairs shared the B14, DR1 haplotype); three other relatives (one father and two brothers) had partial IgA deficiency and did not have the B14, DR1, DQW1 haplotype.

Adolescent↗
PubMed1988

Italian extended HLA haplotypes in congenital adrenal hyperplasia.

In order to complete the data on human 21-Hydroxylase deficiency, we present a study on HLA markers in 35 Italian families (14 from Northern, eight from Central and 13 from Southern Italy) with one affected child. Three children from the issue of first cousin marriages were homozygous for the whole HLA haplotype. Extended haplotypes shared by unrelated patients were not found, and a total absence of the HLA Bw47 allele among the haplotypes carrying the disease as well as normal haplotypes was observed. The absence of A1 Cw7 B8 BfS C4AQ0 C4B1 DR3 extended haplotype was instead confirmed. Allele frequencies in the different clinical forms were analyzed: BfSO7 allele frequency was significantly increased on haplotypes of the salt-wasting form (p less than 0.01). We noticed two duplications (C4B1-2) of C4B genes, on haplotypes involved in the disease. Allele distribution in the regions studied showed that Bw22 (w55), Cw3 and DR2 were characteristic of Northern patients, while B15 was found in patients from Central Italy.

Adrenal Hyperplasia, Congenital↗
PubMed1988

C4A7: a new variant of human complement C4.

A rare variant of complement C4 was found in 2 related individuals. It has the most anodic mobility found to date, no hemolytic activity detected by the overlay technique and a Bgl II RFLP pattern very similar to that of the C4A6 type.

Alleles↗