HLA genetic polymorphisms and prognosis of patients with COVID-19

Objective

Different genetic polymorphisms of human leukocyte antigen (HLA) have been associated with the risk and prognosis of autoimmune and infectious diseases. The objectives of this study were to determine whether there is an association between HLA genetic polymorphisms and the susceptibility to and mortality of coronavirus disease 2019 (COVID-19) patients.

Design

Observational and prospective study.

Setting

Eight Intensive Care Units (ICU) from 6 hospitals of Canary Islands (Spain).

Patients

COVID-19 patients admitted in ICU and healthy subjects.

Interventions

Determination of HLA genetic polymorphisms.

Main variable of interest

Mortality at 30 days.

Results

A total of 3886 healthy controls and 72 COVID-19 patients (10 non-survivors and 62 survivor patients at 30 days) were included. We found a trend to a higher rate of the alleles HLA-A*32 (p = 0.004) in healthy controls than in COVID-19 patients, and of the alleles HLA-B*39 (p = 0.02) and HLA-C*16 (p = 0.02) in COVID-19 patients than in healthy controls; however, all these p-values were not significant after correction for multiple comparisons. Logistic regression analysis showed that the presence of certain alleles was associated with higher mortality, such as the allele HLA-A*11 after controlling for SOFA (OR = 7.693; 95% CI = 1.063-55.650; p = 0.04) or APACHE-II (OR = 11.858; 95% CI = 1.524-92.273; p = 0.02), the allele HLA-C*01 after controlling for SOFA (OR = 11.182; 95% CI = 1.053-118.700; p = 0.04) or APACHE-II (OR = 17.604; 95% CI = 1.629-190.211; p = 0.02), and the allele HLA-DQB1*04 after controlling for SOFA (OR = 9.963; 95% CI = 1.235-80.358; p = 0.03).

Conclusions

The new finding from our preliminary study of small sample size was that HLA genetic polymorphisms could be associated with COVID-19 mortality; however, studies with a larger sample size before definitive conclusions can be drawn.

HLA genetic polymorphisms and prognosis of patients with COVID-19

Objective

Different genetic polymorphisms of human leukocyte antigen (HLA) have been associated with the risk and prognosis of autoimmune and infectious diseases. The objectives of this study were to determine whether there is an association between HLA genetic polymorphisms and the susceptibility to and mortality of coronavirus disease 2019 (COVID-19) patients.

Design

Observational and prospective study.

Setting

Eight Intensive Care Units (ICU) from 6 hospitals of Canary Islands (Spain).

Patients

COVID-19 patients admitted in ICU and healthy subjects.

Interventions

Determination of HLA genetic polymorphisms.

Main variable of interest

Mortality at 30 days.

Results

A total of 3886 healthy controls and 72 COVID-19 patients (10 non-survivors and 62 survivor patients at 30 days) were included. We found a trend to a higher rate of the alleles HLA-A*32 (p = 0.004) in healthy controls than in COVID-19 patients, and of the alleles HLA-B*39 (p = 0.02) and HLA-C*16 (p = 0.02) in COVID-19 patients than in healthy controls; however, all these p-values were not significant after correction for multiple comparisons. Logistic regression analysis showed that the presence of certain alleles was associated with higher mortality, such as the allele HLA-A*11 after controlling for SOFA (OR = 7.693; 95% CI = 1.063–55.650; p = 0.04) or APACHE-II (OR = 11.858; 95% CI = 1.524–92.273; p = 0.02), the allele HLA-C*01 after controlling for SOFA (OR = 11.182; 95% CI = 1.053–118.700; p = 0.04) or APACHE-II (OR = 17.604; 95% CI = 1.629–190.211; p = 0.02), and the allele HLA-DQB1*04 after controlling for SOFA (OR = 9.963; 95% CI = 1.235–80.358; p = 0.03).

Conclusions

The new finding from our preliminary study of small sample size was that HLA genetic polymorphisms could be associated with COVID-19 mortality; however, studies with a larger sample size before definitive conclusions can be drawn.

Further description of early clinically silent lupus nephritis

Thirty silent lupus nephritis (SLN) patients were compared to 16 individuals bearing overt lupus nephritis (OLN). Results included: years of systemic lupus erythematosus (SLE) diagnosis were significantly earlier (4.6 ± 2.8 years) in SLN than in OLN (7.18 ± 3.61) ( P < 0.05). Neurological compromise, hypertension, normocitic anemia and lymphopenia were significantly prevalent in OLN than in SLN ( P < 0.05). Beside normal urinary sediment and renal function tests, the SLN group showed a moderate increase of both activity (AI) and chronicity (CI) renal pathology index when compared to highly increased AI and CI in OLN ( P < 0.05). Seventy percent of SLN patients were ISN/RPS Classes I (6.6%) and II (63.3%) while 81% of OLN cases were Classes III, IV (37.5%) and V. IgG, IgA, IgM, λchain, C3 and fibrinogen immune deposits were found in 90% or over in both SLN and OLN individuals while in 60% or over, both groups also showed K chain, C1q and C4 deposits. While prevalence of ANA, anti-dsDNA and anti-C1q antibodies were similar in both groups, anti-histone, anti-RNP, CIC and CH50 serum levels were significantly different in OLN versus SLN ( P < 0.05). We strongly suggest that indeed SLN is the earliest stage in the natural history of lupus nephritis.

Definition and insertion of the GSPC in the political context of Mexico

Mexico as a megadiverse country houses between 6 and 8% of the world's flora. However, the Mexican flora is facing challenges, including the presence of at least 981 threatened plant species and 618 exotic plant species, habitat loss, pollution, overexploitation of natural resources and the adverse effects of climate change, which are compromising its conservation and sustainable use. Mexico has been actively involved in the development and update of the Global Strategy for Plant Conservation (GSPC) adopted by the Convention on Biological Diversity (CBD). As a party to CBD, Mexico has established a Coordinating Committee for the Mexican Strategy for Plant Conservation (MSPC), which has adapted the GSPC to fit national needs and drafted a number of projects, indicators, means of verification and actors to ensure that the MSPC, as a public policy tool, really drives conservation and sustainable use actions among all sectors and lasts beyond the current administration. An agenda is being developed with activities that include the following: approaching Congress, identifying the relevance of the MSPC in the National Development Plan and the Mexican Biodiversity Strategy, making use of current environmental policies and an aggressive awareness programme. The MSPC includes simultaneous programmes of technical and political work.

[Pro-hepcidin, its relation with indicators of iron metabolism and of inflammation in patients hemodialyzed treated or not with recombinant erythropoietin]

Hepcidin, an antimicrobial peptide which synthesis is regulated by iron status and inflammation, plays an important role in iron homeostasis in hemodialysed (HD) patients. It is measured by measuring serum prohepcidin.

OBJECTIVE

To determine serum prohepcidin levels and their relationship with serum ferritin, C reactive protein (CRP), and albumin in HD patients treated or not with recombinant erythropoietin (EPO) that attended the Health Centre of the Carabobo State in Venezuela.

METHODOLOGY

This is a descriptive, correlational, and field investigation with a sample comprised by 71 HD patients of whom 57 were treated with EPO. Serum prohepcidin, ferritin, haemoglobin, hematocrit, CRP, and albumin were determined. Anaemia (haemoglobin < 10 g/dL) and iron deficiency (ferritin < 100 ng/mL) were defined according to the criteria recommended by the K/DOQUI group. Reference values: Albumin 3.5-4.8 g/dL, and for acute inflammatory conditions (CRP > 10 mg/L.).

RESULTS

The mean value for prohepcidin was 397.5 ng/mL. A high percentage of anaemia was observed (87.3%) and 22.5% of the patients had low levels of serum ferritin. There were no statistically significant differences for ferritin, albumin, CRP, or prohepcidin, between patients with and without EPO therapy. Only the CRP value was significantly correlated (rho = 0.276; p = 0.020) with prohepcidin.

CONCLUSION

HD patients present high levels of prohepcidin, and this may be due to the common ongoing inflammatory process in these patients and not to the iron status measured through serum ferritin levels.

A Randomized Trial Comparing Two Corticosteroid Regimens Combined With Mycophenolate Mofetil and Cyclosporine for Prevention of Acute Renal Allograft Rejection

INTRODUCTION

The launching of mycophenolate mofetil (MMF) has reduced the incidence of acute rejection episodes. We sought to evaluate the efficacy of decreasing the steroid dose.

MATERIALS AND METHODS

This was a quasiexperimental, randomized, prospective trial. We enrolled 150 patients who received de novo renal transplantations from living or cadaveric donors, fulfilling the screening criteria. Patients were randomized to one of the following two arms: (A) MMF at a 2 g/d dose, cyclosporine (CsA) at a dose necessary to achieve target levels, and corticosteroids at the usual doses; (B) MMF at a 2 g/d dose, CsA at a dose necessary to achieve target levels, and corticosteroids at doses 50% lower than those of group A.

RESULTS

Group A included 72 (48%) and group B, 78 patients (52%). There were no differences among the variables: leukopenia occurred in 11 patients in group A, and five patients in group B. Complications occurred in 67.4% (56) of group A, but only 32.6% (27) were related to infections. One case of urinary infection occurred in group B, while six occurred in group A. There was one case of acute rejection in group A, and none in group B. One graft loss occurred in group A. There were no differences in the remaining variables under study.

DISCUSSION

The results showed an increased complication rate related to receiving usual steroid doses. There was no increase in acute rejection episodes among patients receiving 50% of the usual steroid dose.

Role of apolipoprotein E epsilon 4 allele on chronic allograft nephropathy after renal transplantation

Lipid abnormalities may contribute to chronic allograft nephropathy (CAN). Apolipoprotein E (ApoE) gene polymorphism regulates lipoprotein metabolism, but little is known about an association between CAN and this polymorphism. The ApoE gene (E3/E4) polymorphism was typed by PCR assay (99 E3/E3, 28 E3/E4, 1 E4/E4) on 128 consecutive renal transplant patients with functioning grafts for more than 3 years (6.7 +/- 2.8 years). Twenty-eight patients with histological CAN were compared with 100 patients who had no clinical evidence of chronic rejection (no proteinuria and sCr < 2.5 mg%). As expected, univariate analysis revealed that patients with CAN experienced a greater acute rejection rate (78% vs 21%; P=.001), a higher serum creatinine (3.6 +/- 1.7 vs 1.4 +/- 0.5 mg%; P=.0001), and an older organ donor (43 +/- 20 vs 29 +/- 13 years; P=.0001). The lipid profiles (total cholesterol and triglycerides levels) were similar in both groups with 60% in each group receiving anti-lipemic drugs. Interestingly, the ApoE epsilon 4 allele was overrepresented in the group with CAN (39% vs 17%, P=.019). Logistic regression analysis showed that the epsilon 4 allele was an independent predictor of CAN (OR: 3.4; CI 95%: 1.07 to 11; P=.040) as were donor age and acute rejection episodes. In conclusion, an interaction between risk factors and genetic factors may determine CAN in this population. This finding may help to target prophylactic interventions in these recipients.

Influence of Angiotensin-Converting Enzyme Polymorphism Gene, IGF-1, and Other Factors in the Response Rate of Hematocrit to Enalapril Treatment in Patients With Posttransplant Erythrocytosis

A significant relationship between hematocrit values and serum parameters such as the insulin like growth factor (IGF-1) and calcium was observed in patients with posttransplant erythrocytosis (PTE). Since angiotensin-converting enzyme inhibitors (ACEI) decrease hematocrit (Ht) levels in these patients, ACE genotype should play an important role. We designed this study to investigate whether ACE genotype or baseline concentrations of IGF-1, IGF-blood binding protein 3 (BP3), growth hormone (GH), or Ca influenced the response of Ht to ACEI treatment. Twenty-one kidney graft recipients with PTE were treated with enalapril (2.5 to 5 mg/d) for 1 year. IGF-1, BP3, GH, Ca, and Ht were determined before as well as 15, 30, 90, 180, and 365 days after enalapril treatment. ACE polymorphism was also determined. Enalapril treatment significantly decreased Ht levels. Only IGF-1 baseline levels showed a positive correlation to the decreased Ht (P < .025). ACE genotype as determined in 18 patients, showed no correlation with the response to enalapril. Patients with ACE genotype II showed a tendency to an earlier display of PTE. We conclude that low doses of enalapril decrease Ht levels in PTE patients; that PTE begins earlier in patients with II ACE genotype; and that only IGF-1 baseline levels influence the Ht decrease after treatment. These observations suggest that ACEI decrease the Ht via an inhibitory effect on IGF-1, which has a stimulary effect on erythropoiesis.

Modeling the growth plates in the pediatric knee: implications for anterior cruciate ligament reconstruction

The authors develop 3-D models of the pediatric knee from magnetic resonance imaging (MRI) image files, with the goal of minimizing injury to the pediatric growth plate during surgery. Computerized tomography (CT) scans have better resolution and contrast between bone and soft tissue than MRI scans; however, surgeons rely upon MRI scans to plan knee-joint surgeries such as anterior cruciate ligament (ACL) reconstruction. Surgeons can use the virtual models to plan and verify surgical procedures such as hole drilling and ligament attachments, and to determine volume removed from a growth plate due to different drill-hole placements with various drill sizes.

Tumour spectrum of non-polyposis colorectal cancer (Lynch syndrome) on the island of Tenerife and influence of insularity on the clinical manifestations

Colorectal cancer is a complex disease from a genetic point of view because both genetic and environmental factors interact in its development. Only familial adenomatous polyposis (FAP) follows mendelian genetics, in that mutations of the APC gene lead to development of the tumours. Lynch syndrome is the most frequent form of hereditary colorectal cancer and appears to be associated with other types of extracolonic cancers. The genetic basis has been established as a defect in DNA mismatch repair genes, and there is genetic heterogeneity due to the involvement of several genes in this system. Germinal mutations in these genes predispose to appearance of the syndrome. The aim of this study is to describe the tumoral spectrum of 10 families, comprising a total of 488 individuals, from the island of Tenerife (Canary Islands) and to assess whether the geographical isolation of this population has changed any features of the tumoral spectrum of the syndrome in comparison with studies that cover larger geographical areas with more genetic exchange. From our results we can conclude that the genetic drift and consanguinity in this population with a demographic history of isolation did not significantly alter the tumoral spectrum of the syndrome. Our data confirm that families affected by Lynch syndrome are a high-risk population and should be closely monitored, since their careful supervision has been shown to be useful in preventing cancer. We also emphasize the importance of developing a complete family history that permits these families to be identified together with a mutational screening of DNA mismatch repair genes (mainly MLH1 and MSH2 genes) with the aim of a possible identification of members of a family that should be carefully monitored (the carriers of germline mutations in these genes), whereas the remaining members, originally, are no more at risk than the general population.

Genotipo y expresión fenotípica de la hemocromatosis hereditaria en España

INTRODUCTION

The prevalence of C282Y homozygosity in patients with hereditary hemochromatosis (HH) has been reported to be markedly lower in the Mediterranean Basin than in northern Europe. In Spain, the available data are contradictory and limited to small series in specific regions. The objective of this study is to determine the prevalence of the 2 main HFE gene mutations in a large series of unrelated Spanish patients with HH from different geographical origins.

PATIENTS AND METHOD

The criteria for HH diagnosis were: repeat serum transferrin saturation index (> 45% plus C282Y homozygosity and/or hepatic iron index (> 1.9 of dry liver weight in non-cirrhotic patients or (> 4.1 in patients with liver cirrhosis. Cases in related individuals were excluded. Demographic data, clinical expression, iron parameters and HFE gene mutations (C282Y and H63D) were assessed in 222 patients.

RESULTS

A total of 83.3% of patients were C282Y homozygous and 5% were compound heterozygous (C282Y/H63D). No significant differences in phenotypic expression or in the frequency of C282Y homozygosity were observed between patients born in the North and South of Spain.

CONCLUSION

The genotypic and phenotypic expression of HH in Spain is very similar to that reported in Northern Europe. Thus, the genetic heterogeneity described in some Southern European regions cannot be considered a common feature to all countries of the Mediterranean Basin.

[Bone metabolism alterations after kidney transplantation]

Early after renal transplantation (RT) a rapid decrease in bone mineral density at the lumbar spine, femoral neck, and femoral shaft has been documented. In addition, an appreciable proportion of patients still remain losing bone late after RT. As a consequence, RT patients are at a high risk of bone fractures as compared to general population. Most fractures involve appendicular skeleton, particularly the feet and ankles, and the diabetic patient is at increased risk of fractures. Thus, early institution of preventive measures and treatment of established osteoporosis are central. The major cause of post-transplantation bone loss is corticosteroid treatment, and this should be used at the lower dose compatible with graft survival. Preexisting hyperparathyroidism also affects the early cancellous bone loss at the spine, and post-transplantation bone loss reflects variable individual susceptibility, resembling the polygenic determination of bone mineral density in general. Clinical trials have demonstrated that bisphosphonates or vitamin D plus calcium supplementation, prevent post-transplantation bone loss during the first 6-12 months. However, their role in preventing bone fractures has not been proven. Finally, recommendations for management, prevention and treatment, are summarized.

Severe cutaneous vasculitis following intravenous infusion of gammaglobulin in a patient with type II mixed cryoglobulinemia

Intravenous infusion of gammaglobulins (IVIG) is one of the treatments of choice in patients with type II mixed cryoglobulinemia (MC). We describe the case of a patient with MC who suffered an adverse generalised reaction with severe cutaneous vasculitis accompanied by a sudden increase in cryocrit levels shortly after being treated with IVIG. When the same gammaglobulin preparation was added in vitro to a sample of the patient's serum, a strong increment in cryoglobulin precipitation and depletion of the monoclonal IgM peak resulted. We suggest that this simple method of studying the displacement of the precipitation reaction could help to predict the outcome of treatment and must be performed before starting IVIG in patients with MC.

[Helicobacter pylori and immunogenetic factors of the host: relevance of the HLADQA1 *0102 and *0301 alleles in peptic ulcer]

AIM

To investigate the potential contribution of the *0102 and *0301 alleles of the HLADQA1 gene in Helicobacter pylori infection and peptic ulcer disease in a Spanish Caucasian population.

PATIENTS AND METHODS

We studied 163 patients with peptic ulcer (117 duodenal ulcers and 46 gastric ulcers; 111 with recent upper gastrointestinal hemorrhage) and 90 controls. The *0102 and *0301 alleles of the HLADQA1 gene were typed by polymerase chain reaction using genomic DNA. H. pylori infection were determined by breath test and/or serology. The cytotoxins CagA and VacA were investigated using serology (Western-blot) in 98 patients and 48 controls with H. pylori infection.

RESULTS

H. pylori infection was found in 94.6% of patients with duodenal ulcer, in 84.4% of those with gastric ulcer and in 67.4% of controls (p < 0.001). The distribution of the *0102 allele of the HLADQA1 gene was similar in patients (31.9%) and in controls (36.7%). The *0301 was more frequent in patients with gastric ulcer (32.6%) than in those with duodenal ulcer (16.2%) (p < 0.05) but no differences were found on comparison with the control group (24.4%). No differences were found when the groups were analyzed according to H. pylori infection, CagA- and VacA-positive strains, consumption of non-steroidal antiinflammatory drugs or previous history of ulcer or hemorrhage.

CONCLUSION

The *0102 and *0301 alleles of the HLADQA1 gene did not alter susceptibility to H. pylori infection or the evolution of peptic ulcer disease in a Caucasian population in Spain.

Autoantibody activity of the immunoglobulin secreted by a follicular B-cell lymphoma

In patients with B-cell lymphoma, only in rare cases a secreted paraprotein is found, and in very few of them an associated autoantibody activity has been demonstrated. Here we report the case of a patient with a low-grade B-cell lymphoma with a serum biclonal paraprotein (G,M)lambda and severe erythroblastopenia. Indirect immunofluorescence studies of total serum revealed cytoplasmic (Hep-2 cells) and extracellular matrix (rat tissue sections) staining, suggestive of a new specificity. After gel filtration of serum samples, only the IgM-containing fraction showed the same pattern of staining. Tumor-derived hybridomas expressed an unmutated V3-11 gene identical to that found in tumor samples and secreted an IgM immunoglobulin endowed with the same reactivity, which confirms the tumoral origin of the tissue-reactive protein. The results suggest a link between the autoimmune condition in this patient and the novel specificity displayed by the tumor-derived immunoglobulin.

Infusion of lymphocytes obtained from a donor immunised with the paraprotein idiotype as a treatment in a relapsed myeloma

A 48-year-old patient with IgA k multiple myeloma received a BMT from his HLA-matched sibling. After transplantation, the disease relapsed. Melphalan therapy followed by reinfusion of haemopoietic blood stem cells collected from the patient led to the improvement of the clinical status, although mixed chimerism and an elevated serum IgA persisted. Successful donor immunisation against an immunogenic preparation of the recipient monoclonal protein was performed before the infusion of donor T lymphocytes (DLI) into the patient. Ten weeks after the lymphocyte infusions, no monoclonal band was evidenced and donor complete chimerism was detected. The patient did not develop GVHD. Once complete remission was achieved, the idiotype vaccine was administered to the patient. Nineteen months after DLI, the patient remains in remission. Bone Marrow Transplantation (2000).

The distribution of two different vitamin D receptor polymorphisms (BsmI and start codon) in primary hyperparathyroidism

INTRODUCTION

The bb genotype of the BsmI polymorphism of the vitamin D receptor (VDR) is more common in primary hyperparathyroidism (HPT) than in the general population in Swedish and German women. However, little is known about the association of HPT with the start codon polymorphism of the VDR (defined by FokI).

OBJECTIVE

To study the distribution of the VDR genotypes in a group of women with HPT compared with a control group. The bone mineral density (BMD) of different genotypes was also investigated.

METHODS

VDR alleles were typed by polymerase chain reaction (PCR) assay around the polymorphic BsmI or FokI restriction sites in 67 control women (48.5 +/- 10 years) and 53 women with HPT (61.4 +/- 11 years). They were all Caucasian and born in the Canary Islands. Lumbar and proximal femur BMDs were measured by dual X-ray absorptiometry (DXA) and quantitative computed tomography (QCT).

RESULTS

The 'bb' genotype was equally frequent in controls and HPT subjects (46.3 and 45.3%, respectively). There was a trend towards a lower prevalence of the FF genotype amongst women with HPT as compared with controls (41.5 vs. 57.1%; P = 0.09). BMD was lower in patients with HPT compared with controls in the lumbar spine and the proximal femur.

CONCLUSIONS

The association of the BsmI polymorphism of the VDR gene with HPT is not applicable to all geographical areas. In Canarian postmenopausal women suffering from HPT, VDR genotype distribution is similar to that found in controls. A possible association of HPT with the FokI polymorphism deserves further investigation.

The PlA2 polymorphism of the platelet glycoprotein IIIA gene as a risk factor for acute renal allograft rejection

Glycoprotein IIIa/IIb is a membrane receptor for fibrinogen and von Willebrand factor that plays an important role in platelet aggregation. The beta integrin chain of this receptor, GPIIIa, is polymorphic, and the allele known as PlA2 has been associated with coronary thrombosis. The GPIIIa genotype of a cohort of 119 consecutive renal allograft recipients (46.3 +/- 13 yr; 85 M/34 F; 24.4% diabetic patients) was determined by PCR-restriction fragment length polymorphism, and those patients were followed for at least 12 mo. From 119 patients with at least 1 yr of follow-up, those who suffered an acute rejection (n = 52) showed a lower proportion of HLA-DR beta1 identity with the donor (7.7% versus 23.9%; P = 0.03), a higher proportion of cytomegalovirus-positive (CMV+) donors/CMV- recipients (21% versus 7.5%; P = 0.05), and the PlA2 allele was more frequent (48.1% versus 26.9%; P = 0.02) compared with patients free of acute rejection (n = 67). No other variable was associated with acute rejection in the univariate analysis. The impact of the three above-mentioned significant variables on acute rejection was analyzed by stepwise logistic regression. The presence of the PlA2 allele yielded an odds ratio of 2.75 (95% confidence interval, 1.01 to 7.93) and an HLA-DR beta1 identity of 0.2 (95% confidence interval, 0.06 to 0.99) for suffering an acute rejection episode. In addition, the serum creatinine at discharge was higher in PlA2-positive versus PlA2-negative patients (2.2 +/- 1.6 versus 1.5 +/- 0.6 mg/dl, respectively; P = 0.01), and the prevalence of proteinuria >1.5 g/d 1 yr after transplantation was significantly higher among patients showing the PlA2 allele (16% versus 3%; P = 0.02). Finally, in the entire cohort of patients, the 2-yr graft survival was significantly lower in PlA2-positive (n = 43) compared with PlA2-negative (n = 76) patients (85.7% versus 97.2%; P = 0.015). No differences were found in patient survival (95.2% versus 98.7%, respectively). Proportional hazards regression analysis (Cox regression model) confirmed that serum creatinine level at discharge is the best predictor of allograft survival, followed by CMV status, delayed graft function, and the glycoprotein IIIa/IIb genotype. The PlA2 polymorphism is an independent risk factor for acute renal graft rejection, affecting short-term graft survival. Future studies aimed at preventing the hemostatic imbalance favoring platelet aggregation associated with this polymorphism may be important in preventing acute rejection and its impact on chronic rejection.

An association between viral genes and human oncogenic alterations: the adenovirus E1A induces the Ewing tumor fusion transcript EWS-FLI1

Malignant transformation of human cells requires the accumulation of multiple genetic alterations, such as the activation of oncogenes and loss of function of tumor suppressor genes or those related to genomic instability. Among the genetic alterations most frequently found in human tumors are chromosomal translocations that may result in the expression of chimeric products with transforming capability or are able to change the expression of oncogenes. We show here that the adenovirus early region 1A (E1A) gene can induce a specific human fusion transcript (EWS-FLI1) that is characteristic of Ewing tumors. This fusion transcript was detected by RT-PCR in normal human fibroblasts and keratinocytes after expression of the adenovirus E1A gene, as well as in human cell lines immortalized by adenoviruses. Cloning and sequencing of the RT-PCR product showed fusion points between EWS and FLI1 cDNA identical to those detected in Ewing tumors. In addition, we detected a chimeric protein by western blot analysis and immunoprecipitation and a t(11,22) by fluorescent in situ hybridization. This association between a single viral gene and a specific human fusion transcript indicates a direct link between viral genes and chromosome translocations, one of the hallmarks of many human tumors.

Vitamin D receptor gene polymorphisms, bone mass, bone loss and prevalence of vertebral fracture: differences in postmenopausal women and men

Bone mineral density (BMD), the major determinant of fracture risk, is under strong genetic control. Although polymorphisms of the vitamin D receptor (VDR) gene have been suggested to account for some of the genetic variation in bone mass, the influence of VDR genotypes on osteoporosis remains controversial. Previous published studies have focused mainly on women, but the pattern of response in men has not been determined. Using the BsmI restriction enzyme, we studied the influence of the different VDR genotypes on bone mass, bone loss and the prevalence of vertebral fractures in a population-based sample of both sexes (n = 326). BMD was measured at the lumbar spine and femoral neck, with a 4-year interval, using dual-energy X-ray absorptiometry. Vertebral fractures were assessed by two lateral radiographs at the beginning and end of the study. The prevalence of the three possible VDR genotypes was similar to those in other Caucasian populations and no differences were found between men and women. Women with the favorable bb genotype showed significantly higher BMD values at the lumbar spine and femoral neck, and a positive rate of BMD change at the femoral neck compared with women with the BB and Bb genotypes. Moreover, women with the bb genotype showed a trend toward a lower prevalence and incidence of vertebral fractures (p = 0.07). We have not found any differences between VDR genotypes in men. In conclusion, VDR gene polymorphisms are related to bone mass and bone loss in women; also a trend in the prevalence of vertebral fractures was observed in postmenopausal women but not in men.

[Genetic polymorphism of vitamin D receptor and osteoporosis]

BACKGROUND

Genetic factors condition an important part of bone mass. The role of vitamin D receptor polymorphism (VDR) as genetic marker of osteoporosis is a matter of discussion. We have studied the possible influence of VDR on bone remodelling, calciotropic hormones, on the presence of osteoporosis and osteoporotic bone fractures. PATIENTS, CONTROL POPULATION AND METHODS: A case-control study. We have studied a total of 127 postmenopausal Canarian women from Canary Islands, Spain; 66 healthy controls and 61 with the diagnosis of osteoporosis, which was made by clinical, radiological and densitometric criteria. 17 osteoporotic women have had a fracture: Colles, hip or vertebral (spinal deformity index) fracture. VDR were determined by PCR directed to demonstrate the presence (b) or absence (B) of a restriction target for Bsml in intron 7. We analyzed some biochemical markers of bone remodelling: serum levels of alkaline phosphatase, tartrate resistant acid phosphatase and urine ratios of calcium/creatinine and hydroxyproline/creatinine. We also determined calciotropic hormones: parathyroid hormone and calcitonin. Bone mass was measured by DEXA and TC.

RESULTS

There were no significant differences in either biochemical bone remodelling markers or in bone mass between the three genotypes: bb, Bb and BB, either in controls or in osteoporotic women with the exception of alkaline phosphatase which had a significative increase compared to control in women with unfavorable alleles distribution (bB and BB). Distribution of genotypes was similar between controls and osteoporotic women, with or without fractures.

CONCLUSIONS

In Canarian women, VDR genotype is not associated with changes in biochemical markers of bone remodelling or in bone mass or with the presence of osteoporosis or osteoporotic fractures.

Prediction of left ventricular mass changes after renal transplantation by polymorphism of the angiotensin-converting-enzyme gene

Cardiac complications are the main cause of death in renal transplant patients and left ventricular hypertrophy (LVH) may play a determinant role. An association between the insertion-deletion polymorphism of the angiotensin-converting enzyme (ACE) gene and LVH has been reported in adults. However, little is known about the genetic influence on left ventricular mass changes after renal transplantation, where unique environmental factors, such as cyclosporine A (CsA) and prednisone treatment concur. In fact, CsA treatment has recently been associated with the development of LVH. We prospectively determined the changes on cardiac structure and function, assessed by echocardiographic criteria, in 38 consecutive nondiabetic adults who received a cadaveric renal allograft. They were treated with cyclosporine and prednisone and maintained a good renal function during the follow-up. Echocardiographic studies (M-mode, 2-B and color flow Doppler) were performed without previous knowledge of the genetic typing, at the time of transplantation, and 6 and 12 months later. ACE alleles were typed using a PCR-based assay developed to ascertain the presence of an insertion (I)-deletion (D) polymorphism in intron 16 of the ACE gene. Patients with the so-called "unfavorable" DD genotype (N = 16) were compared with the ID or II genotypes (N = 22). The baseline left ventricular mass index was similar in patients with or without the unfavorable DD genotype (X +/- SE; 166.6 +/- 10.4 vs. 181.3 +/- 9 g/m2, respectively) and a similar proportion fulfilled the criteria of LVH (88% vs. 82%, respectively). The mean percent increase of the left ventricular mass index 12 months after renal transplantation was significantly higher in patients with the DD genotype compared to those with other genotypes (21.3 +/- 7.9 vs. -0.08 +/- 4.9%, respectively; P < 0.05). As a result, 94% of DD patients showed LVH at the end of the follow-up, while 68% of the ID or II patients had LVH (P < 0.05). In addition, the left ventricular ejection fraction significantly increased only in ID or II patients 12 months after transplantation with respect to baseline (ID/II patients, 70.4 +/- 1.5 vs. 63.7 +/- 1.8%; P < 0.05; DD patients, 68.3 +/- 2.1 vs. 63.3 +/- 2.9%). The deleterious effect of the DD genotype was independent of blood pressure, biochemical parameters, weight gain, and cumulative steroids dosages or cyclosporine levels. In conclusion, genetic factors determine the changes on cardiac structure and function after renal transplantation. The presence of the DD genotype of the ACE gene is a marker associated with an elevated risk of LVH in this population.

Constitutive NOS isoforms account for gastric mucosal NO overproduction in uremic rats

To study whether renal failure enhances gastric mucosal nitric oxide (NO) formation in the rat, we measured 1) in vivo NO concentration and 2) NO synthase (NOS) activity, content, and mRNA expression in gastric mucosal homogenates of uremic and sham-operated anesthetized rats. Gastric mucosal NO release was measured by an electrochemical technique. NOS content was analyzed by Western immunoblots, using specific monoclonal antibodies. Constitutive (Ca2+ dependent; cNOS) and inducible (Ca2+ independent; iNOS) NOS activities were assayed by following the conversion of L-[U-14C]arginine to [U-14C]citrulline. mRNA expression for the constitutive neuronal (ncNOS), endothelial (ecNOS), and iNOS isoforms was determined by reverse transcription-polymerase chain reaction. Under basal conditions, gastric mucosal NO concentration was significantly greater in uremic compared with control rats. This was accompanied by significantly greater gastric mucosal cNOS activity in uremic rats than in control rats, whereas no differences were observed in iNOS activity between both groups of animals. Moreover, total enzyme content and the levels of gastric mucosal mRNA expression for ncNOS, ecNOS, and iNOS showed no significant differences between uremic and sham-operated rats. These data confirm that, in uremic rats, enhanced Ca2+-dependent NOS activity is responsible for gastric mucosal NO overproduction and suggest that the main regulatory mechanism is not transcriptional but translational and/or posttranslational in nature.

[Safety in the switching traditional cyclosporin to microemulsion cyclosporin in stable renal transplant patients: cooperative study]

In an open clinical trial we assessed the tolerance and safety of the 1:1 conversion of traditional cyclosporine A (CyA) to a new cyclosporine formulation based on a microemulsion technology (CyN) in 18 patients with stable renal allografts. 56% patients were female. Median patient age was 40.9 +/- 3.2 years (range 18 to 65). Renal transplantation was performed in 24.1 +/- 4.6 months (range 6 to 67 months), prior to the beginning of the study, and 67% of the transplants were from cadaveric donor. The most frequent underlying renal disease was glomerulonephritis (44.4%). None of the patients entering the study were withdrawn prematurely. After 2 weeks of observation for graft function stability, the study was divided in two phases: I: during 4 weeks the patients received CyA traditional at fixed doses (Mean dose administered 3.056 +/- 0.25 mg/Kg/d) and II: during the consecutive 6 weeks with conversion to CyN, with doses adjustment as required (Mean dose 2.887 +/- 0.21 mg/Kg/d). Clinical events, adverse reactions and laboratory parameters were evaluated. Levels of 100-200 ng/ml measured by monoclonal specific fluorescence polarization immunoassay were considered appropriate. There were no significant changes in physical examination and laboratory parameters between phases. The incidence of adverse reactions reported in phase I was only gingival hypertrophy (5%) which persisted in phase II, qualified as probably related to the cyclosporine, and in phase II tremor in 17%, qualified as definitively related. Both drugs were well tolerated and there was no report of acute rejection during the study. We conclude that the tolerance and safety of the 1:1 conversion of CyA to CyN were confirmed by our results, and considering the improved pharmacokinetic properties of the second, the microemulsion presentation will be used preferentially as immunosuppressive drug in the treatment of stable kidney transplant patients.