Validating the Fracture Risk Assessment Tool Score in a US Population-Based Study of Patients With Rheumatoid Arthritis.

OBJECTIVE: The World Health Organization fracture risk assessment tool (FRAX) algorithm for risk prediction of major osteoporotic and hip fractures accounts for several risk factors, including rheumatoid arthritis (RA), since individuals with RA have an excess burden of fractures. FRAX has not been validated in population-based RA cohorts in the US. We aimed to determine the accuracy of FRAX predictions for individuals with RA in the US. METHODS: This retrospective population-based cohort study included residents of Olmsted County, Minnesota, who were followed until death, migration, or last medical record review. Each patient with RA (1987 American College of Rheumatology criteria met in 1980-2007, age 40-89 years) was matched 1:1 on age and sex to an individual without RA from the same underlying population. Ten-year predictions for major osteoporotic and hip fractures were estimated using the FRAX tool. Fractures were ascertained through follow-up, truncated at 10 years. Standardized incidence ratios (SIRs) and 95% CI were calculated to compare observed and predicted fractures. RESULTS: The study included 662 patients with RA and 658 non-RA comparators (66.8% vs 66.9% female and a mean age of 60.6 vs 60.5 years, respectively). Among patients with RA, 76 major osteoporotic fractures and 21 hip fractures were observed during follow-up (median follow-up: 9.0 years) compared to 67.0 predicted major osteoporotic fractures (SIR 1.13, 95% CI 0.91-1.42) and 23.3 predicted hip fractures (SIR 0.90, 95% CI 0.59-1.38). The observed and predicted major osteoporotic and hip fracture risks were similar for patients with RA and non-RA comparators. CONCLUSION: The FRAX tool is an accurate method for estimating major osteoporotic and hip fracture risk in patients with RA.

Tracer metabolomics reveals the role of aldose reductase in glycosylation.

Abnormal polyol metabolism is predominantly associated with diabetes, where excess glucose is converted to sorbitol by aldose reductase (AR). Recently, abnormal polyol metabolism has been implicated in phosphomannomutase 2 congenital disorder of glycosylation (PMM2-CDG) and an AR inhibitor, epalrestat, proposed as a potential therapy. Considering that the PMM2 enzyme is not directly involved in polyol metabolism, the increased polyol production and epalrestat's therapeutic mechanism in PMM2-CDG remained elusive. PMM2-CDG, caused by PMM2 deficiency, presents with depleted GDP-mannose and abnormal glycosylation. Here, we show that, apart from glycosylation abnormalities, PMM2 deficiency affects intracellular glucose flux, resulting in polyol increase. Targeting AR with epalrestat decreases polyols and increases GDP-mannose both in patient-derived fibroblasts and in pmm2 mutant zebrafish. Using tracer studies, we demonstrate that AR inhibition diverts glucose flux away from polyol production toward the synthesis of sugar nucleotides, and ultimately glycosylation. Finally, PMM2-CDG individuals treated with epalrestat show a clinical and biochemical improvement.

N-glycoproteomics reveals distinct glycosylation alterations in NGLY1-deficient patient-derived dermal fibroblasts.

Congenital disorders of glycosylation are genetic disorders that occur due to defects in protein and lipid glycosylation pathways. A deficiency of N-glycanase 1, encoded by the NGLY1 gene, results in a congenital disorder of deglycosylation. The NGLY1 enzyme is mainly involved in cleaving N-glycans from misfolded, retro-translocated glycoproteins in the cytosol from the endoplasmic reticulum before their proteasomal degradation or activation. Despite the essential role of NGLY1 in deglycosylation pathways, the exact consequences of NGLY1 deficiency on global cellular protein glycosylation have not yet been investigated. We undertook a multiplexed tandem mass tags-labeling-based quantitative glycoproteomics and proteomics analysis of fibroblasts from NGLY1-deficient individuals carrying different biallelic pathogenic variants in NGLY1. This quantitative mass spectrometric analysis detected 8041 proteins and defined a proteomic signature of differential expression across affected individuals and controls. Proteins that showed significant differential expression included phospholipid phosphatase 3, stromal cell-derived factor 1, collagen alpha-1 (IV) chain, hyaluronan and proteoglycan link protein 1, and thrombospondin-1. We further detected a total of 3255 N-glycopeptides derived from 550 glycosylation sites of 407 glycoproteins by multiplexed N-glycoproteomics. Several extracellular matrix glycoproteins and adhesion molecules showed altered abundance of N-glycopeptides. Overall, we observed distinct alterations in specific glycoproteins, but our data revealed no global accumulation of glycopeptides in the patient-derived fibroblasts, despite the genetic defect in NGLY1. Our findings highlight new molecular and system-level insights for understanding NGLY1-CDDG.

Acetazolamide treatment in late onset CDG type 1 due to biallelic pathogenic DHDDS variants.

Pathogenic variants in DHDDS have been associated with either autosomal recessive retinitis pigmentosa or DHDDS-CDG. Heterozygous variants in DHDDS have been described in patients with a progressive neurodegenerative disease. Here we report on an individual presenting with a multisystem CDG phenotype who was diagnosed with known homozygous pathogenic DHDDS variants, previously associated with isolated retinitis pigmentosa. An adult Ashkenazi Jewish female developed multiple symptoms of late onset type 1 CDG including seizures, ataxia, protein losing enteropathy, tremor, and titubation in association with elevated mono-oligo/di-oligo transferrin ratio in blood, and classic retinitis pigmentosa. She was diagnosed by whole exome sequencing with the common Ashkenazi Jewish, homozygous p.K42E variants in DHDDS. She was started on Acetazolamide and responded well to the treatment which improved her titubation, tremor, and generalized edema. Reviewing the literature, families with DHDDS variants and multisystem presentation were different from our patient's presentation in terms of clinical manifestations, severity, genetic defect, and mode of inheritance. In previously reported patients with neurologic symptoms including seizures, movement abnormalities, and global development delay, the phenotype was caused by heterozygous pathogenic variants in DHDDS. The infant who was reported with a multisystem phenotype and fatal type 1 CDG had compound heterozygosity for a nonsense and a splice site variant in DHDDS, resulting in DHDDS-CDG. The discovery of the novel phenotype associated with the common p.K42E pathogenic variant in DHDDS expands the spectrum of CDG and further enhances our understanding on the role of DHDDS in glycosylation beyond the retina.

Syndromic obesity with neurodevelopmental delay: Opportunities for targeted interventions.

Obesity is a growing public health problem in many developed countries, although similar trends are increasingly being described in some developing nations. The genetic underpinnings of obesity continue to arouse increasing research interests, investigations, and discussions. The recent advances in next generation sequencing technologies have shed some more light on the diverse monogenic and polygenic causes of obesity. Syndromic obesity due to chromosomal or monogenic defects has attendant co-morbidities, which may include neurodevelopmental delays, dysmorphism as well as organ-specific developmental anomalies. An improved understanding of the nature of neurodevelopmental challenges in syndromic obesity may pave the way for personalized dietary and physical activity management approaches. This review article describes the clinical and molecular genetic aspects of obesity-related syndromes and the associated neurodevelopmental disabilities. The potential opportunities for individualized nutrigenomic managements of syndromic obesity are also highlighted.

Secondary Prophylaxis of Gastric Variceal Bleeding: A Systematic Review and Network Meta-Analysis.

There is no clear consensus regarding the optimal approach for secondary prophylaxis of gastric variceal bleeding (GVB) in patients with cirrhosis. We conducted a systematic review and network meta-analysis (NMA) to compare the efficacy of available treatments. A comprehensive search of several databases from each database's inception to March 23, 2021, was conducted to identify relevant randomized controlled trials (RCTs). Outcomes of interest were rebleeding and mortality. Results were expressed as relative risk (RR) and 95% confidence interval (CI). We followed the Grading of Recommendations Assessment, Development, and Evaluation approach to rate the certainty of evidence. We included 9 RCTs with 647 patients who had histories of GVB and follow-ups >6 weeks. A total of 9 interventions were included in the NMA. Balloon-occluded retrograde transvenous obliteration (BRTO) was associated with a lower risk of rebleeding when compared with ß-blockers (RR, 0.04; 95% CI, 0.01-0.26; low certainty), and endoscopic injection sclerotherapy (EIS)-cyanoacrylate (CYA) (RR, 0.18; 95% CI, 0.04-0.77; low certainty). ß-blockers were associated with a higher risk of rebleeding compared with most interventions and with increased mortality compared with EIS-CYA (RR, 4.12, 95% CI, 1.50-11.36; low certainty), and EIS-CYA + nonselective ß-blockers (RR, 5.61; 95% CI, 1.91-16.43; low certainty). Analysis based on indirect comparisons suggests that BRTO may be the best intervention in preventing rebleeding, whereas ß-blocker monotherapy is likely the worst in preventing rebleeding and mortality. Head-to-head RCTs are needed to validate these results.

Mannose treatment improves immune deficiency in mannose phosphate isomerase-congenital disorder of glycosylation: case report and review of literature.

Mannose phosphate isomerase-congenital disorder of glycosylation (MPI-CDG) is a CDG presenting with a clinically recognizable presentation, including early hypoglycemia, coagulation defects, and gastrointestinal and hepatic symptoms. We report on a female patient with biallelic pathogenic mutations in the MPI gene who presented with recurrent respiratory infections and abnormal IgM levels, but none of the classic symptoms associated with MPI-CDG. Oral mannose therapy led to a fast improvement in serum IgM levels and transferrin glycosylation in our patient. The patient did not experience severe infections after the initiation of treatment. We also reviewed the immune phenotype in patients so far reported with MPI-CDG.

Using a type of sugar called mannose to strengthen the immune system of a person living with a rare disease called MPI-congenital disorder of glycosylation Mannose phosphate isomerase­congenital disorder of glycosylation (MPI-CDG for short) is a rare, inherited disease that mainly affects the liver and digestive system. People with MPI-CDG typically develop signs and symptoms of the condition during childhood. Common symptoms of MPI-CDG include low blood sugar, blood clotting problems, poor growth, low weight, swelling of the lower legs or hands, digestive problems, and liver problems. Early diagnosis is crucial for people with MPI-CDG, as it is a potentially life-threatening, but treatable disease. Given that there are a small number of people with MPI-CDG, especially those with symptoms related to their immune system, it is important to highlight specific cases to raise awareness. This article summarizes a specific case study of a female child with MPI-CDG. This individual did not experience the usual signs and symptoms of the disease. However, she had multiple infections affecting her respiratory tract, and had abnormal levels of antibodies in her blood. The patient was treated with mannose, a type of sugar that is related to fructose and glucose. After 12 months of treatment, levels of antibodies stabilized. Furthermore, she did not experience any more severe infections after starting treatment with mannose. Tests designed to measure levels of glycosylation, called glycosylation transferrin testing, showed improvement in glycosylation to almost normal levels. In conclusion, this case report adds to the current knowledge about the disease and raises awareness that patients can present with immunological problems. It also shows that mannose treatment can be an effective treatment to improve the immune system and glycosylation in MPI-CDG.