Pharmacogenetic and clinical risk factors for bevacizumab-related gastrointestinal hemorrhage in prostate cancer patients treated on CALGB 90401 (Alliance)

The objective of this study was to discover clinical and pharmacogenetic factors associated with bevacizumab-related gastrointestinal hemorrhage in Cancer and Leukemia Group B (Alliance) 90401. Patients with metastatic castration-resistant prostate cancer received docetaxel and prednisone ± bevacizumab. Patients were genotyped using Illumina HumanHap610-Quad and assessed using cause-specific risk for association between single nucleotide polymorphisms (SNPs) and gastrointestinal hemorrhage. In 1008 patients, grade 2 or higher gastrointestinal hemorrhage occurred in 9.5% and 3.8% of bevacizumab (n = 503) and placebo (n = 505) treated patients, respectively. Bevacizumab (P < 0.001) and age (P = 0.002) were associated with gastrointestinal hemorrhage. In 616 genetically estimated Europeans (n = 314 bevacizumab and n = 302 placebo treated patients), grade 2 or higher gastrointestinal hemorrhage occurred in 9.6% and 2.0% of patients, respectively. One SNP (rs1478947; HR 6.26; 95% CI 3.19-12.28; P = 9.40 × 10-8) surpassed Bonferroni-corrected significance. Grade 2 or higher gastrointestinal hemorrhage rate was 33.3% and 6.2% in bevacizumab-treated patients with the AA/AG and GG genotypes, versus 2.9% and 1.9% in the placebo arm, respectively. Prospective validation of these findings and functional analyses are needed to better understand the genetic contribution to treatment-related gastrointestinal hemorrhage.

CYP2C19 loss-of-function alleles are not associated with higher prevalence of gastrointestinal bleeds in those who have been prescribed antidepressants: Analysis in a British-South Asian cohort

AIMS

CYP2C19 is a hepatic enzyme involved in the metabolism of antidepressants associated with increased gastrointestinal bleed (GIB) risk. The aim of our study was to explore a possible association between loss-of-function CYP2C19 genotypes and GIB in South Asian ancestry participants prescribed antidepressants.

METHODS

Genes & Health participants with a record in Barts Health NHS Trust (N 22 753) were studied using a cross-sectional approach. CYP2C19 diplotypes were assessed and metabolizer type inferred from consortia guidance. Fisher's exact test was used to compare the prevalence of GIB in different metabolizer categories. Multivariable regression was used to test for association between antidepressant prescriptions and GIB, and between CYP2C19 metabolizer state and GIB in the subcohort prescribed antidepressants.

RESULTS

Antidepressants were frequently prescribed (47%, N = 10 612). A total of 864 participants (4%) had a GIB; 534 (62%) had been prescribed a CYP2C19 metabolized antidepressant. There was an independent association between antidepressant prescriptions and GIB events (odds ratio 1.8, confidence interval 1.5-2.0, P < 0.0001). There was no relationship between CYP2C19 inferred poor (P 0.56) or intermediate (P 0.53) metabolizer status and GIB in those prescribed an antidepressant in unadjusted analysis. A multivariable logistic regression model did not show an independent association between poor (P 0.54) or intermediate (P 0.62) CYP2C19 metabolizers and GIB in the subcohort prescribed antidepressants.

CONCLUSIONS

CYP2C19 dependent antidepressants are associated with increased GIB prevalence. GIB appeared independent from CYP2C19 metabolizer genotype in individuals who had been prescribed antidepressants. Precision dosing based on CYP2C19 genetic information alone is unlikely to reduce GIB prevalence.

VNTR Polymorphism in Intron 4 of the eNOS Gene and the Risk of Gastrointestinal Bleeding: A Case-control Study

BACKGROUND AND AIMS

Considering the lack of knowledge regarding the influence of the variable number of repeats of 27 pb in intron 4 (4b/4a VNTR - rs61722009) of the endothelial nitric oxide synthase (eNOS) on the drug response, we assessed the influence of this polymorphism for the risk of upper gastrointestinal bleeding (UGIB).

METHODS

A case-control study, including 200 cases and 706 controls, was conducted in a Brazilian hospital complex. Cases were participants with UGIB diagnosis. Controls were participants admitted to surgical procedures not related to gastrointestinal problems. The 4b/4a VNTR was determined through polymerase chain reaction followed by fragment analysis. Conditional logistic regression models were designed. The additive interaction between the presence of the 4b/4a VNTR variant and the use of low-dose aspirin (LDA) and nonsteroidal anti-inflammatory drugs (NSAIDs) was calculated by fitting the Cox regression model through the parameters of Synergism index (S) and Relative Excess Risk Due To Interaction (RERI).

RESULTS

The presence of the 4b/4a VNTR variant did not increase the risk of UGIB: carriers of the 4a/4a genotype (OR=0.37, 95%CI: 0.09-1.45) and of the variant allele "4a" (OR=0.91, 95%CI: 0.55-1.51). The risk of UGIB in LDA users carriers of the wild genotype (OR=4.96, 95%CI: 2.04- 2.06) and the variant allele "4a" (OR=3.49, 95%CI: 1.18-10.38) is similar, as well as for NSAID users carriers of the wild genotype (OR=5.73, 95%CI: 2.61-12.60) and variant allele "4a" (OR=5.51, 95%CI: 1.42-15.82). No additive interaction was identified between the presence of the genetic variant and the use of LDA [RERI: -1.44 (95%CI: -6.02-3.14; S: 0.63 (95%CI: -1.97-1.15)] and NSAIDs [RERI: -0.13 (95%CI: -6.79-6.53; S: 0.97 (95%CI: -0.23-4.19)] on the UGIB risk.

CONCLUSION

Our data suggests that there is no increase in the magnitude of UGIB risk in LDA and NSAIDs users' carrying the variant allele "4a".

CD36 maintains the gastric mucosa and associates with gastric disease

The gastric epithelium is often exposed to injurious elements and failure of appropriate healing predisposes to ulcers, hemorrhage, and ultimately cancer. We examined the gastric function of CD36, a protein linked to disease and homeostasis. We used the tamoxifen model of gastric injury in mice null for Cd36 (Cd36-/-), with Cd36 deletion in parietal cells (PC-Cd36-/-) or in endothelial cells (EC-Cd36-/-). CD36 expresses on corpus ECs, on PC basolateral membranes, and in gastrin and ghrelin cells. Stomachs of Cd36-/- mice have altered gland organization and secretion, more fibronectin, and inflammation. Tissue respiration and mitochondrial efficiency are reduced. Phospholipids increased and triglycerides decreased. Mucosal repair after injury is impaired in Cd36-/- and EC-Cd36-/-, not in PC-Cd36-/- mice, and is due to defect of progenitor differentiation to PCs, not of progenitor proliferation or mature PC dysfunction. Relevance to humans is explored in the Vanderbilt BioVu using PrediXcan that links genetically-determined gene expression to clinical phenotypes, which associates low CD36 mRNA with gastritis, gastric ulcer, and gastro-intestinal hemorrhage. A CD36 variant predicted to disrupt an enhancer site associates (p < 10-17) to death from gastro-intestinal hemorrhage in the UK Biobank. The findings support role of CD36 in gastric tissue repair, and its deletion associated with chronic diseases that can predispose to malignancy.

Genetic polymorphisms associated with upper gastrointestinal bleeding: a systematic review

Non-variceal upper gastrointestinal bleeding (non-variceal UGIB) is a frequent and severe adverse drug reaction. Idiosyncratic responses due to genetic susceptibility to non-variceal UGIB has been suggested. A systematic review was conducted to assess the association between genetic polymorphisms and non-variceal UGIB. Twenty-one publications and 7134 participants were included. Thirteen studies evaluated genetic polymorphism in patients exposed to non-steroidal anti-inflammatory drugs, low-dose aspirin, and warfarin. Eight studies present at least one methodological problem. Only six studies clearly defined that the outcome evaluated was non-variceal UGIB. Genetic polymorphisms involved in platelet activation and aggregation, angiogenesis, inflammatory process, and drug metabolism were associated with risk of non-variceal UGIB (NOS3, COX-1; COX-2; PLA2G7; GP1BA; GRS; IL1RN; F13A1; CDKN2B-AS1; DPP6; TBXA2R; TNF-alpha; VKORC1; CYP2C9; and AGT). Further well-designed studies are needed (e.g., clear restriction to non-variceal UGIB; proper selection of participants; and adjustment of confounding factors) to provide strong evidence for pharmacogenetic and personalized medicine.

Mutations in the ENG, ACVRL1, and SMAD4 genes and clinical manifestations of hereditary haemorrhagic telangiectasia: experience from the Center for Osler's Disease, Uppsala University Hospital

AIM

The aim of this retrospective single-centre study was to evaluate whether mutations in the ENG, ACVRL1, and SMAD4 genes were associated with different phenotypes in hereditary haemorrhagic telangiectasia (HHT).

METHODS

The case records of 21 HHT patients with verified mutations in ENG, ACVRL1, or SMAD4 genes were reviewed. The numbers of HHT diagnostic criteria fulfilled for the three genotypes were compared, as was the prevalence of complications such as iron deficiency anaemia, gastrointestinal haemorrhage, stroke, and cerebral abscess.

RESULTS

Our results indicate that mutations in the ENG (HHT1), ACVRL1 (HHT2), and SMAD4 genes result in different HHT phenotypes. Epistaxis debuts earlier and may be more severe in HHT1 than in HHT2. The prevalence of pulmonary arteriovenous malformations (AVM) is higher in HHT type 1, whereas hepatic AVMs are more common in HHT2. One patient with mutations in both ENG and ACVRL1 genes was identified, as were two SMAD4-mutated patients suffering from the overlapping juvenile polyposis-HHT syndrome. Nearly one in five patients in our HHT population has been diagnosed with stroke or cerebral abscess, indicating a high prevalence of cerebral complications.

CONCLUSION

Our results showing that ENG and ACVRL1 gene mutations result in different HHT phenotypes confirm the results from other HHT centres worldwide. Cerebral complications of HHT are common, underscoring the importance of regular screening for pulmonary AVMs and early intervention against such AVMs. We have identified an HHT patient with simultaneous mutations in the ENG and ACVRL1 genes. Surprisingly, this patient has had a mild course of the disease.

Rack1 maintains intestinal homeostasis by protecting the integrity of the epithelial barrier

Previously, we generated mouse models of Rack1 deficiency to identify key functions for Rack1 in regulating growth of intestinal epithelia: suppressing crypt cell proliferation and regeneration, promoting differentiation and apoptosis, and repressing development of neoplasia. However, other than low body weight, we did not detect an overt phenotype in mice constitutively deleted of Rack1 in intestinal epithelia ( vil-Cre: Rack1fl/fl mice), presumably because Rack1 was deleted in <10% of the total surface area of the epithelia. To assess the effect of Rack1 loss throughout the entire intestinal epithelia, we generated another mouse model of Rack1 deficiency, vil-Cre-ERT2: Rack1fl/fl. Within 5-10 days of the initial tamoxifen treatment, the mice lost over 20% of their body weight, developed severe diarrhea that for some was bloody, became critically ill, and died, if not euthanized. Necropsies revealed mildly distended, fluid-, gas-, and sometimes blood-filled loops of small and large bowel, inguinal lymphadenopathy, and thrombocytosis. Rack1 was deleted in nearly 100% of the epithelia in both the small intestine and colon when assessed by immunofluorescent or immunoblot analyses. Rack1 expression in other tissues and organs was not different than in control mice, indicating tissue specificity of the recombination. Histopathology revealed a patchy, erosive, hemorrhagic, inflammatory enterocolitis with denuded, sloughed off surface epithelium, and crypt hyperplasia. These results suggest a protective function for Rack1 in maintaining the integrity of intestinal epithelia and for survival. NEW & NOTEWORTHY Our findings reveal a novel function for Rack1 in maintaining intestinal homeostasis by protecting the epithelial barrier. Rack1 loss results in a patchy, erosive, hemorrhagic, inflammatory enterocolitis, which resembles that of inflammatory bowel diseases (IBD) in humans. Understanding mechanisms that protect barrier function in normal intestine and how loss of that protection contributes to the pathogenesis of IBD could lead to improved therapies for these and other erosive diseases of the gastrointestinal tract.

[HORMONALLY-GENETICALLY DEPENDENT THERAPY, USING VITAMIN K IN PATIENTS, SUFFERING THE ULCER HEMORRHAGE]

Pathophysiological mechanisms of the vitamin K impact, including those in the gut with ulcerative affection, are studied still insufficiently. Investigations of pharmacogenomics of the vitamin K gives a new approach to therapy in patients, suffering gastro-intestinal hemorrhage. Possibilities of titration of the vitamin K3 (menadione) doses, depending on level of estrogenemia and genetic constitution, concerning genes-candidates ESR1 (rs2234693) and VKORC1 (rs9923231), were studied. There were examined 36 patients, who were treated for the ulcer hemorrhage. The blood serum concentration of estradiol was investigated in accordance to method of solid phase enzyme immunoassay, the genotyping procedure was performed in accordance to indices of polymerase chain reaction with analysis of the restrictional fragments length. The initial daily dose of menadione have constituted 20 mg. After a genotype determination made (first-second day after admittance to hospital) in patients with normoestrogenemia in genotypes CC/GG, CC/GA, CT/GG, CT/GA a vitaminotherapy was prolonged in daily dose of 20 mg, and in a conditionally-pathological variant of genotype the dose of vitamin K was enhanced up to 30 mg. Determination of hormones and the patients' genetic constitution makes possible to apply a personified approach for the vitamin K3 application in the ulcerative hemorrhage.

Expression of Angiogenic Factors in Patients With Sporadic Small Bowel Angiodysplasia

GOALS

To identify putative angiogenic factors associated with sporadic small bowel angiodysplasia (SBA).

BACKGROUND

SBAs account for 50% of obscure gastrointestinal bleeding and due to delays in diagnosis and ineffective treatments, are associated with high levels of morbidity and mortality. Treatment development is impeded by a limited knowledge of the pathophysiology behind SBA formation.

STUDY

We identified patients with definite sporadic SBA, and fecal immunochemical-negative controls were recruited from our institution's colorectal cancer screening program. Serum levels of VEGF, endoglin, Angiopoietin-2 (Ang-2), PDGF, Angiopoietin-1 (Ang-1), and TNF-α were measured using commercially available enzyme-linked immunosorbent assay kits. On the basis of serum results, we measured gene expression of target angiogenic factors in small bowel biopsy samples from angiodysplasias and unaffected tissue by quantitative PCR assessment.

RESULTS

Serum samples were analyzed from 40 SBA patients and 40 controls. Median serum levels of Ang-2 were significantly higher in patients than controls with levels of Ang-1 and TNF-α significantly lower. There were no differences in serum levels of VEGF, endoglin, or PDGF. Gene expression levels of Ang-1, Ang-2, and their receptor Tie2 were all significantly higher in biopsies from areas of angiodysplasia compared with normal small bowel.

CONCLUSIONS

This study, the first to explore the role of angiogenic factors in SBA, has identified a positive association between SBA and the Angiopoietin pathway, with increased serum and mucosal expression of Ang-2, which could potentially be used as a serum biomarker and future therapeutic target to improve outcome in affected patients.

Endoscopic finding of spontaneous hemorrhage correlates with tumor necrosis factor alpha expression in colonic mucosa of patients with ulcerative colitis

BACKGROUND

Ulcerative colitis (UC) is an intractable colonic disease, and it shows several endoscopic findings. Recently, it was reported that the expression level of mucosal tumor necrosis factor alpha (TNF-α) was useful for predicting patient response to infliximab. However, no data regarding the value of endoscopic findings to predict treatment efficacy or cytokine expression level exist.

OBJECTIVE

We investigated the expression of leukocyte adhesion-related molecules and cytokines in colonic mucosa and compared it to endoscopic findings.

METHODS

One hundred and fifty-nine patients were enrolled. Tissue samples were obtained by colonic biopsy from patients with UC. Colitis activity was determined by Matts' criteria. The degree of mRNA expression of TNF-α, interferon gamma (IFN-γ), interleukin (IL)-8, IL-17A, and mucosal vascular addressin adhesion molecule-1 (MAdCAM-1) in mucosal samples was determined by real-time quantitative polymerase chain reaction. These expression levels were compared with the degree of Matts' grade and individual endoscopic findings.

RESULTS

The expression of TNF-α, IFN-γ, IL-8, IL-17A, and MAdCAM-1 mRNA significantly increased as Matts' endoscopic grade elevated. Actively inflamed mucosa with spontaneous hemorrhage revealed a significantly increased expression level of TNF-α mRNA than that without spontaneous hemorrhage. No other individual endoscopic parameter was significantly correlated with the expression level of TNF-α mRNA.

CONCLUSIONS

Inflamed mucosa with spontaneous hemorrhage may suggest increased expression of TNF-α mRNA levels in colonic mucosa of UC patients, which could predict a lower response to infliximab treatment and more aggressive induction regime or change to other therapy should be taken into account.

[28-year-old patient with iron deficiency anemia]

We report the case of a 28-years-old woman with Turner's syndrome and iron deficiency anaemia. The faecal occult blood test was intermittently positive whereas earlier upper and lower endoscopy revealed no source of bleeding. Capsule endoscopy showed multiple vascular malformations on the jejunum and ileum. Our case report emphasizes the importance of capsule endoscopy in the localising occult bleedings in the small bowel. We discuss the different diagnostic modalities and possible treatments.

The relationship between CYP2C9 gene polymorphisms and upper gastrointestinal bleeding in patients who used warfarin

AIM

Oral anticoagulants are the most common used substance for treatment and prophylaxis of warfarin venous and arterial thromboembolic disorders in the world. Therapeutic index of warfarin is narrow. CYP2C9 is a hepatic microsomal enzyme and has a primary role in metabolism of warfarin and genetic variations of CYP2C9 may cause a serious effect on the response to warfarin in patients. The aim of this study was to determine the efficiency of CYP2C9 gene polymorphisms on drug metabolism in patients who had upper gastrointestinal system bleeding while using warfarin.

METHODS

There was a total of 67 patients in this study, 37 of whom had upper gastrointestinal system bleeding when INR was above 3 while using warfarin (group 1), 30 of whom had no bleeding and INR was stable under 3 (group 2).

RESULTS

There was no difference in terms of warfarin dose used among the groups (p>0.05). Mutant genotype, INR and aspirin usage were found significantly different in the group with bleeding (p less 0.05). When analyzed in terms of drug interaction, there was no difference between the two groups (p>0.05). Logistic regression analysis was made in order to determine the risk factors that may cause bleeding. Aspirin usage (p= 0.016) and genetic polymorphism (p= 0.024) were related to the increased risk of bleeding.

CONCLUSION

CYP2C9*2 and CYP2C9*3 polymorphisms were related to the increase of excessive anticoagulation and bleeding risk in the patients who used warfarin.

Differences in acute toxicity syndromes of 2,3,7,8-tetrachlorodibenzo-p-dioxin and 1,2,3,4,7,8-hexachlorodibenzo-p-dioxin in rats

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is the most potent congener of polychlorinated dibenzo-p-dioxins. The potency of 1,2,3,4,7,8-hexachlorodibenzo-p-dioxin (HxCDD) is only 10% of that of TCDD for typical aryl hydrocarbon receptor (AHR)-mediated effects. Acute lethality, macroscopic effects, and liver toxicity of TCDD and HxCDD were compared in male rats of the strain Han/Wistar (Kuopio; H/W), and of the lines A and B. The latter two rat lines originate from crossbreeding of H/W and Long-Evans (Turku/AB) rats. H/W and line A rats are highly resistant to acute toxicity of TCDD due to an altered AHR, while line B rats are moderately resistant due to H/W-type alleles of another, yet unidentified gene contributing to TCDD resistance ("gene B"). The rats received 200-10,000 microg/kg of either TCDD or HxCDD intragastrically and were monitored for 46 days. In all rats, the highest dose of HxCDD (10,000 microg/kg) reduced body weight more effectively than an identical dose of TCDD. Only HxCDD (10,000 microg/kg) caused gastrointestinal hemorrhage, pale (fatty) livers and death by day 15 in H/W and line A rats. In line B rats, HxCDD caused pronounced hepatic fatty degeneration, whereas TCDD induced hepatic accumulation of biliverdin and its derivatives. Both congeners induced sinusoidal distension in liver. In H/W and line A rats, the estimated LD(50) values were >10,000 microg/kg and 2000-10,000 microg/kg for TCDD and HxCDD, respectively; for line B rats they were 480 microg/kg and 1000-2000 microg/kg, respectively. Thus, HxCDD was more potent than TCDD in inducing acute mortality in H/W and line A rats, contrary to what is predicted by toxic equivalency factor (TEF) values. In line B, the expected rank order of potencies prevailed. These findings suggest that in addition to the canonical AHR-mediated toxic pathways, HxCDD possesses an AHR-independent mechanism of toxicity, whose main manifestations are rapid body weight loss, mortality, fatty liver and gastrointestinal hemorrhage.

A genetically determined dose-volume histogram predicts for rectal bleeding among patients treated with prostate brachytherapy

PURPOSE

To examine whether possession of genetic alterations in the ATM (ataxia telangiectasia) gene is associated with rectal bleeding in a dose-dependent and volume-dependent manner.

METHODS AND MATERIALS

One hundred eight prostate cancer patients who underwent brachytherapy using either an (125)I implant, a (103)Pd implant, or the combination of external beam radiotherapy with a (103)Pd implant and had a minimum of 1 year follow-up were screened for DNA sequence variations in the 62 coding exons of the ATM gene using denaturing high-performance liquid chromatography. Rectal dose was reported as the volume (in cubic centimeters) of rectum receiving the brachytherapy prescription dose. The two-sided Fisher exact test was used to compare differences in proportions.

RESULTS

A significant correlation between the presence of any ATM sequence alteration and Grade 1 to 2 proctitis was obtained when the radiation dose to rectal tissue was quantified. Rectal bleeding occurred in 4 of 13 patients (31%) with a variant versus 1 of 23 (4%) without a genetic alteration for patients who had <0.7 cm(3) of rectal tissue receiving the implant prescription dose (p = 0.05). Of patients in whom 0.7-1.4 cm(3) of the rectum received the implant prescription, 4 of 11 (36%) with an ATM alteration exhibited Grade 1 to 2 proctitis, whereas 1 of 21 (5%) without a variant (p = 0.04) developed this radiation-induced late effect.

CONCLUSIONS

The possession of genetic variants in the ATM gene is associated with the development of radiation-induced proctitis after prostate cancer radiotherapy for patients who receive the full prescription dose to either a low or a moderate volume of rectal tissue.

Homozygous 23-bp insertion of endothelial protein c receptor gene in a child with fatal sepsis

Endothelial protein C receptor (EPCR) is primarily localized on the endothelial cells of large blood vessels and is very low or absent in the microvascular endothelium of most tissues. EPCR augments the thrombin/thrombomodulin-dependent activation of protein C by 5- to 20-fold. EPCR appears to be physiologically significant in the control of blood coagulation and inflammation and in the host response to gram-negative sepsis. Here, the authors report an 8-month-old boy, who had chronic liver disease due to undetermined cause. He had Staphylococcus aureus and Candida albicans sepsis and died due to gastrointestinal, lung, and peritoneal bleeding during follow-up. Serum soluble EPCR level of the patient was high (225 ng/mL) during sepsis. A homozygous 23-bp insertion of EPCR gene was demonstrated. This case indicates the importance the EPCR gene plaus in pediatric sepsis. Homozygous 23-bp insertion of the EPCR gene may be associated with a tendency to sepsis and poor outcome.

Clinical symptoms according to genotype amongst patients with hereditary haemorrhagic telangiectasia

BACKGROUND

Hereditary haemorrhagic telangiectasia (HHT) is a dominantly inherited disease, characterized by a wide variety of clinical manifestations, including epistaxis, gastrointestinal (GI) bleeding, pulmonary arteriovenous malformations (PAVMs) and neurological symptoms. HHT is a genetically heterogeneous disorder involving at least two loci; HHT 1 mapping to chromosome 9 q 34.1 (ENG) and HHT 2 mapping to chromosome 12 q 31 (ALK-1).

OBJECTIVE

To evaluate and describe the diversity of clinical manifestations in a Danish population of HHT patients with known HHT 1 or HHT 2 subtype.

DESIGN

Prospective clinical examination with genetic evaluation and follow-up.

SETTING

Investigation centre was Odense University Hospital. All HHT patients in the County of Fyn were included.

METHODS

HHT family members were invited to a clinical examination including registration of HHT manifestations, screening for PAVM and neurological evaluation. Blood tests were performed for analysis of disease-causing mutation, and clinical manifestations in the HHT subtypes were compared. The survival of the patients was studied in the follow-up period.

RESULTS

Included in the study were 73 HHT patients representing 18 families. In 14 of the families we identified a disease-causing mutation. Thirty-nine patients (from 10 families) had HHT1 and 16 HHT patients from four families had HHT2.

CONCLUSION

Amongst patients with HHT1 genotype the prevalence of PAVM was higher than amongst HHT patients with HHT2 genotype. HHT1 patients had experienced more severe GI bleeding than HHT2 patients. There was no significant difference in severity of epistaxis or age at debut. Finally the mortality over a 90-month observation period was not significantly increased.

Genetic predisposition to acute gastrointestinal bleeding after NSAIDs use

Impaired drug metabolism is a major cause of adverse drug reactions, and it is often caused by mutations at genes coding for drug-metabolising enzymes. Two amino-acid polymorphisms of cytochrome P4502C9 (CYP2C9), an enzyme involved in the metabolism of several nonsteroidal anti-inflammatory drugs (NSAIDs), were studied in 94 individuals with acute bleeding after NSAIDs use and 124 individuals receiving NSAIDs with no adverse effects. The frequency of CYP2C9 variant alleles was increased in overall bleeding patients, with a significant trend to higher risk with increasing number of variant alleles (P=0.02). The odds ratio for bleeding patients receiving CYP2C9 substrates (n=33) was 2.5 for heterozygous and 3.7 for homozygous carriers of mutations (P<0.015), suggesting that the inherited impairment of CYP2C9 activity increases the risk for severe adverse drug reactions after NSAIDs use.

T-cell prolymphocytic leukemia with hemorrhagic gastrointestinal involvement and a new chromosomal abnormality

We report a case of T-cell prolymphocytic leukemia in a 56-year-old woman who exhibited hemorrhaging with gastric involvement as the first manifestation. This patient's condition was diagnosed as T-cell prolymphocytic leukemia based on the findings of lymphocytosis, abnormal immunophenotype, hepatosplenomegaly, lymphadenopathy, and cutaneous involvement. Endoscopic examination of the upper gastrointestinal tract revealed hemorrhage from a gastric lesion with histological involvement. Cytogenetic analysis revealed chromosomal abnormalities, 46,XX,der(1), add(1)(p36), that have not previously been described in T-cell prolymphocytic leukemia. In spite of a transient response to chemotherapy, the patient died 15 months after onset of the disease.

Major bleeding caused by warfarin in a genetically susceptible patient

A 90-year-old woman was hospitalized for gastrointestinal bleeding. Although she had been receiving only warfarin 5 mg/day, her international normalized ratio (INR) was 66. Warfarin was discontinued, and her INR fell to 3.7 after transfusion of fresh-frozen plasma. However, it rose again spontaneously to 7.5. Eleven days after the last dose of warfarin had been administered, it was still detectable in the patient's plasma, indicating that impaired warfarin clearance may have caused an enhanced anticoagulation effect. Genetic analysis of the cytochrome P450 (CYP) isoenzyme 2C9, which mediates the major deactivating pathway of S-warfarin, revealed that the patient was a compound heterozygote carrying two variant alleles: CYP2C9*2 and CYP2C9*3. The patient's enhanced sensitivity to warfarin 5 mg/day can be ascribed to decreased clearance of S-warfarin secondary to genetic alteration of the gene encoding CYP2C9, resulting in a life-threatening complication.

HLA-DRB1*01 association with Henoch-Schönlein purpura in patients from northwest Spain

OBJECTIVE

To examine the HLA-DRB1 phenotypes of patients with Henoch-Schönlein purpura (HSP) and determine if associations exist with disease susceptibility, clinical heterogeneity, or severe systemic complications.

METHODS

A retrospective study was performed on an unselected population of patients from Northwest Spain with HSP classified according to proposed criteria. Patients were included in this study if they had at least one year of followup. Fifty Caucasian patients (25 women), 11 of them older than 20 years, were studied. Patients and ethnically matched controls were HLA-DRB1 genotyped from DNA using molecular based methods.

RESULTS

During the course of the disease, renal manifestations, especially hematuria, and severe gastrointestinal (GI) manifestations (bowel angina or GI bleeding) were observed in more than 60% of the patients. Twenty percent of patients had persistent renal involvement (renal sequelae). Patients with HSP had a significantly higher frequency of the HLA-DRB1*01 phenotype compared to matched controls. The HLA-DRB1*07 phenotype was also significantly reduced compared with controls. Patients with severe GI manifestations or with persistent renal involvement did not exhibit any specific HLA-DRB1 association other than the underlying association with HLA-DRB1*01.

CONCLUSION

HSP in a population from Northwest Spain is significantly associated with HLA-DRB1*01.

Gastrointestinal and hepatic manifestations of hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) or Osler-Rendu-Weber (ORW) disease is an autosomal-dominant disorder that frequently presents with gastrointestinal bleeding which may be a diagnostic and therapeutic challenge. Hepatic involvement in this disease is increasingly recognized and poses another therapeutic challenge. With advances in genetic screening and diagnostic procedures, and the increasing awareness of the condition by physicians and patients, this disease is being diagnosed more often. This article reviews the available literature on gastrointestinal and hepatic manifestations of HHT, and the various diagnostic and therapeutic modalities available for its management.

T-cell alpha beta + and gamma delta + deficient mice display abnormal but distinct phenotypes toward a natural, widespread infection of the intestinal epithelium

Vertebrate immune systems contain T cells bearing either alpha beta or gamma delta T-cell antigen receptors (TCRs). alpha beta T cells perform all well-characterized T-cell effector functions, while the biological functions of gamma delta + cells remain unclear. Of particular interest is the role of gamma delta + cells during epithelial infections, since gamma delta + cells are commonly abundant within epithelia. Eimeria spp. are intracellular protozoa that infect epithelia of most vertebrates, causing coccidiosis. This study shows that in response to Eimeria vermiformis, mice lacking alpha beta T cells display defects in protective immunity, while mice lacking gamma delta + cells display exaggerated intestinal damage, apparently due to a failure to regulate the consequences of the alpha beta T cell response. An immuno-downregulatory role during infection, and during autoimmune disease, may be a general one for gamma delta + cells.

von Willebrand's disease with gastrointestinal telangiectasia

A 30-year old woman presented with recurrent and massive bleeding from gastrointestinal tract. Her coagulation profile revealed von Willebrand's disease and her endoscopic examination showed extensive telangiectasia localized to the gastrointestinal tract. The association of Von Willebrand's Disease and telangiectasia is extremely rare and hence the report.

Massive bleeding into the upper gastro-intestinal tract in hereditary chronic calcifying pancreatitis in the child

This report deals with a young girl affected with chronic hereditary calcifying pancreatitis, which gave rise to acute life-threatening arterial bleeding into the upper gastro-intestinal tract. A pancreatic pseudocyst forming in the chronically affected pancreas spontaneously perforated into the stomach, thereby eroding a gastric wall artery. We think it is conceivable that in the future this type of complication in children with pancreatitis and pseudocyst formation might occur more frequently.

Neonatal bleeding in transgenic mice expressing urokinase-type plasminogen activator

Spontaneous intestinal and intra-abdominal bleeding was observed in a high percentage of newborn transgenic mice carrying the murine urokinase-type plasminogen activator (uPA) gene linked to the albumin enhancer/promoter. These hemorrhagic events were directly related to transgene expression in the liver and the development of high plasma uPA levels. Two lines were established from surviving founder mice that displayed multigenerational transmission of the bleeding phenotype. Fatal hemorrhaging developed between 3 and 84 hr after birth in about half of the transgenic offspring of these lines; transgenic pups that did not bleed nevertheless passed the phenotype to their young. The phenotypic variability could not be explained by differences in transgene expression. All transgenic neonates were severely hypofibrinogenemic and displayed loss of clotting function that extended beyond the risk period for bleeding. These mice provide a means of studying the pathophysiology of plasminogen hyperactivation and evaluating therapeutic protocols designed to prevent bleeding.

Digestive tract and renal small vessel hyalinosis, idiopathic nonarteriosclerotic intracerebral calcifications, retinal ischemic syndrome, and phenotypic abnormalities. A new familial syndrome

A new familial syndrome that affected 3 of 7 siblings is described. All 3 patients were young women with a very peculiar phenotype, poikilodermia and hair greying, and idiopathic nonarteriosclerotic cerebral calcifications. Pathological studies demonstrated a marked and progressive hyalinosis involving capillaries and often arterioles and small veins of the digestive tract, kidneys, and calcified areas of the brain. Using electron microscopy, we found that the hyalin substance in the intestinal capillaries consisted of several concentric layers of basal membrane-like deposits within a finely granular fluffy material. Huge deposits of this material were present in the subepithelial and mesangial spaces of the kidneys. Endothelial cells and, in the kidneys, mesangial cells were markedly abnormal, and a true mesangiolysis pattern was present in 2 patients. The clinical and biologic expression of these vascular changes was variable. Diarrhea, rectal bleeding, malabsorption, and protein-losing enteropathy were the main and lethal clinical problems in the proband. Hypertension appeared in the early stage of a second pregnancy in 1 sister, and mild proteinuria was found in all 3 affected patients. Peripheral retinal ischemic syndrome and chorioretinal scars were found in the ocular fundi of both affected sisters of the proband. A subarachnoid hemorrhage, due to a right sylvian aneurism, also occurred in both sisters and was lethal in 1 sister. None of the known causes of distal vessel hyalinosis could be ascertained.

Dyskeratosis congenita: two examples of this multisystem disorder

Two brothers with the X-linked disorder, dyskeratosis congenita, are described. They showed the dermatologic triad of reticular hyperpigmentation, dystrophic nails, and leukoplakia oris as well as the other major feature of this disorder, aplastic anemia. Less common features observed included prenatal and postnatal growth retardation, mental retardation, elevated immunoglobulin levels, and gastrointestinal hemorrhage from mucosal ulceration. Previously unreported findings were intracranial calcifications and nutmeg-like cirrhotic changes of the liver. These brothers demonstrated that skeletal changes and bony fragility may predate anemia or steroid therapy. Although a DNA repair defect is postulated as a possible primary defect, cytogenetic studies revealed no evidence of increased chromosomal breakage.

Acquired von Willebrand's syndrome and Ehlers-Danlos syndrome presenting with gastro-intestinal bleeding

The clinical and laboratory findings in a patient with severe gastro-intestinal bleeding and the Ehlers-Danlos syndrome are described. Coagulation studies and a lack of history of previous haemorrhage were consistent with a diagnosis of acquired von Willebrand's syndrome. His response to treatment with blood transfusion, Factor VIII, cimetidine, tranexamic acid and cyclophosphamide is described. Family studies revealed other members with Ehlers-Danlos syndrome but normal coagulation.

[Congenital gastrointestinal diseases with manifestations in adulthood]

A genetic background is discussed in many disorders of the gastrointestinal tract with a disposition in addition to environmental factors. The pathophysiology of most hereditary diseases is unknown although the mode of inheritance is established. Biochemical analysis may show molecular defects or inborn lack of enzymes, cytogenetic studies may reveal chromosomal abnormalities. The knowledge of genetic factors in gastrointestinal disorders may contribute to the early detection of persons afflicted but not yet symptomatic, in some rare syndromes genetic counseling may become mandatory. Finally, there are many congenital malformations which may not cause symptoms for many years so that doubts may arise whether they are developmental anomalies or acquired conditions.