Identification of four novel delta-globin gene mutations in Greek Cypriots using polymerase chain reaction and automated fluorescence-based DNA sequence analysis.

The molecular basis of most beta-thalassemia syndromes has been defined, while the spectrum of mutations causing delta-thalassemia is not well characterized. In an attempt to identify such mutations, the region encompassing the delta-globin gene from three Greek Cypriot families suspected of having delta-thalassemia was amplified by polymerase chain reaction (PCR), and DNA sequence determined using an automated fluorescence-based sequencer. Four novel mutations were identified: a G----T change at codon 27 that results in an alanine to serine change; a C----T change at codon 116 converting arginine to cysteine; a T----C change at codon 141 converting leucine to proline; and an AG----GG change at the consensus 3'-acceptor site in IVS-2. While the latter is clearly a thalassemic mutation, the low hemoglobin A2 in the first three may be due to either decreased production or instability of the altered delta-globin chain. All four mutations may be detected by PCR amplification of genomic DNA followed by restriction enzyme digestion. Two mutations abolish restriction sites while two create new cleavage sites. Screening for molecular defects that cause delta-thalassemia or unstable delta-globin by PCR amplification and restriction enzyme digestion will lead to correct diagnosis of beta/delta-thalassemia compound heterozygotes and improved genetic counseling.     

Multicenter study of the molecular basis of thalassemia intermedia in different ethnic populations

We studied 325 thalassemia intermedia patients from Iran, India, Pakistan, Thailand, Mauritius and Cyprus to examine factors which influence the phenotype. The beta-thalassemia (thal) mutations were determined for 219 beta-thal/beta-thal and 106 beta-thal/Hb E [beta26(B8)Glu-->Lys, GAG-->AAG] thalassemia intermedia patients. Thirty-one different mutations were identified, and their combination gave rise to more than 44 different genotypes, of which 14 (31.8%) had the beta(0)/beta(0), 21 (47.7%) the beta(0)/beta(+) and nine (20.5%) the beta(+)/beta(+) types. Thus, the beta(+)-thal mutations were present in 68.2% of patients. alpha-Thalassemia mutations were present in frequencies higher than in the general population of all ethnic groups studied, as 45% of the patients carried alpha-thal mutations. Correlation of alpha-thal mutations with beta-globin mutations showed that the alpha-thal mutations were mainly co-inherited with the beta(+)-thal mutations. The XmnI (G)gamma polymorphic site at -158 (C-->T) was positive (T) in nine (8.8%) of 102 patients of the beta(+)/beta(+) genotype, and the percentage of both XmnI (G)gamma polymorphism [+/-] (T/C) and [+/+] (T/T) genotypes increased to 42.9 and 87.3, respectively, in the beta(0)/beta(+) and beta(0)/beta(0) patients. This polymorphism was found in the majority of beta(+)-thal/Hb E compound heterozygote patients (88.6%), and beta(0)-thal/Hb E patients (84.8%), suggesting that it could be linked to the Hb E chromosome. Therefore, the XmnI (G)gamma polymorphism at -158 (C-->T) was associated with beta(0)-thal mutations as well as the Hb E chromosome. The present study demonstrates that in cases of thalassemia intermedia with beta(+) mutations, the common ameliorating factor is the presence of alpha-thal mutations, while in cases with beta(0) mutations, the common ameliorating factor is the presence of the XmnI (G)gamma polymorphism at -158 (C-->T).     

Survival of liver transplant recipients with hemochromatosis in the United States

BACKGROUND AND AIMS: Earlier studies have suggested that patients with hemochromatosis have poor post-transplantation survival. We aimed to compare patients with hemochromatosis to those with other causes of liver disease with regard to post-transplantation survival. METHODS: We compared the post-transplant survival of patients with and without hemochromatosis using data provided by the United Network for Organ Sharing on 50,306 adult, cadaveric liver transplantations performed in the United States between January 1, 1990, and July 18, 2006. RESULTS: During 1990-1996, the post-transplantation survival of patients with hemochromatosis (n = 177) at 1 year (79.1%), 3 years (71.8%), and 5 years (64.6%) was lower than the average 1-year (86.4%), 3-year (79.5%), and 5-year (73.8%) survival of all other transplant recipients (hazard ratio for death, 1.38; 95% confidence interval [CI], 1.12-1.71). In contrast, during 1997-2006, patients with hemochromatosis (n = 217) had excellent 1-year (86.1%), 3-year (80.8%), and 5-year (77.3%) post-transplantation survival, which was not different from the 1-year (88.4%), 3-year (80.3%), and 5-year (74.0%) post-transplantation survival of all other transplant recipients (hazard ratio for death, 0.89; 95% CI, 0.65-1.22). Adjustment for donor and recipient characteristics did not substantially change these results. Compared with recipients without hemochromatosis, those with hemochromatosis were more likely to die of cardiovascular diseases and less likely to die as a result of graft failure. CONCLUSIONS: The post-transplantation survival of patients with hemochromatosis, which was previously reported to be poor, has been excellent in the United States during the past 10 years.     

Comparison of the electrophysiological properties of the sheep isolated costal and diaphragmatic parietal pleura

1. Pleural permeability may contribute to pleural fluid turnover. The transmesothelial resistance (R(TM)), is an established surrogate of mesothelial permeability. The aim of the present study was to compare the electrophysiological properties of costal and diaphragmatic parietal pleura. 2. Specimens of the parietal pleura were isolated from 12 adult sheep from the chest wall and the diaphragm. Electrophysiological measurements were conducted with the Ussing system. Specimens of the parietal pleura of both types (diaphragmatic and costal) were compared histologically and total protein content measurements were also made. 3. The R(TM) of the diaphragmatic parietal pleura was significantly higher than that of the costal parietal pleura throughout the experiment. The diaphragmatic parietal pleura contains more cuboidal cells than the costal parietal pleura and its protein content was higher, however this difference was not statistically significant. 4. The costal parietal pleura consists of a more 'leaky' mesothelium than the diaphragmatic pleura. The morphological differences between the two types of parietal pleura may underline the electrophysiological findings.     

Prevalence,characteristics and outcomes of older patients with hereditary versus wild-type transthyretin amyloid cardiomyopathy

Aims

Transthyretin amyloid cardiomyopathy (ATTR-CM) is often assumed to be associated with wild-type TTR genotype (ATTRwt) in elderly patients (aged ≥70), some of whom are not offered genetic testing. We sought to estimate the prevalence, clinical characteristics and prognostic implications of transthyretin (TTR) variants among elderly patients diagnosed with ATTR-CM.

Methods and results

Data from consecutive patients over 70 years of age diagnosed with ATTR-CM at the UK National Amyloidosis Centre between January 2010 and August 2022 were retrospectively evaluated. All patients underwent clinical evaluation, biochemical tests, echocardiography and TTR genotyping. The study outcome was all-cause mortality. The study population consisted of 2029 patients with ATTR-CM (median age 79 years at diagnosis, 13.5% females, 80.4% Caucasian). Variant ATTR-CM (ATTRv-CM) was diagnosed in 20.7% (n = 421) of the study population of whom 327 (77.7%) carried V122I, 47 (11.2%) T60A, 16 (3.8%) V30M and 31 (7.3%) other pathogenic TTR variants. During a median (range) follow-up of 29 (12–48) months, ATTRv-CM was associated with increased all-cause mortality compared to ATTRwt-CM, with the poorest survival observed in V122I-associated ATTRv-CM (p < 0.001). Univariable and multivariable logistic regression analyses in those with ATTR-CM showed younger age at diagnosis (odds ratio [OR] 0.85 per year, p < 0.001), female sex (OR 2.73, p < 0.001), Afro-Caribbean ethnicity (OR 65.5, p < 0.001), atrial fibrillation (OR 0.65, p = 0.015), ischaemic heart disease (OR 0.54, p = 0.007), peripheral polyneuropathy (OR 5.70, p < 0.001) and orthostatic hypotension (OR 6.29, p < 0.001) to be independently associated with ATTRv-CM.

Conclusion

Up to 20.7% of elderly patients with ATTR-CM have a pathogenic TTR variant. These findings support routine sequencing of the TTR gene in all patients with ATTR-CM regardless of age.     

Optimizing therapy in primary biliary cholangitis: Alkaline phosphatase at six months identifies one-year non-responders and predicts survival

Background and Aims

Patients with primary biliary cholangitis (PBC) and insufficient response to ursodeoxycholic acid (UDCA), currently assessed after 1 year, are candidates for second-line therapy. The aims of this study are to assess biochemical response pattern and determine the utility of alkaline phosphatase (ALP) at six months as a predictor of insufficient response.

Methods

UDCA-treated patients in the GLOBAL PBC database with available liver biochemistries at one year were included. POISE criteria were used to assess response to treatment, defined as ALP <1.67 × upper limit of normal (ULN) and normal total bilirubin at one year. Various thresholds of ALP at six months were evaluated to predict insufficient response based on negative predictive value (NPV) and that with nearest to 90% NPV was selected.

Results

For the study, 1362 patients were included, 1232 (90.5%) female, mean age of 54 years. The POISE criteria were met by 56.4% (n = 768) of patients at one year. The median ALP (IQR) of those who met POISE criteria compared to those who did not was 1.05 × ULN (0.82–1.33) vs. 2.37 × ULN (1.72–3.69) at six months (p < .001). Of 235 patients with serum ALP >1.9 × ULN at six months, 89% did not achieve POISE criteria (NPV) after one year of UDCA. Of those with insufficient response by POISE criteria at one year, 210 (67%) had an ALP >1.9 × ULN at six months and thus would have been identified early.

Conclusions

We can identify patients for second-line therapy at six months using an ALP threshold of 1.9 × ULN, given that approximately 90% of these patients are non-responders according to POISE criteria.