Osteocyte regulation of phosphate homeostasis and bone mineralization underlies the pathophysiology of the heritable disorders of rickets and osteomalacia

Although recent studies have established that osteocytes function as secretory cells that regulate phosphate metabolism, the biomolecular mechanism(s) underlying these effects remain incompletely defined. However, investigations focusing on the pathogenesis of X-linked hypophosphatemia (XLH), autosomal dominant hypophosphatemic rickets (ADHR), and autosomal recessive hypophosphatemic rickets (ARHR), heritable disorders characterized by abnormal renal phosphate wasting and bone mineralization, have clearly implicated FGF23 as a central factor in osteocytes underlying renal phosphate wasting, documented new molecular pathways regulating FGF23 production, and revealed complementary abnormalities in osteocytes that regulate bone mineralization. The seminal observations leading to these discoveries were the following: 1) mutations in FGF23 cause ADHR by limiting cleavage of the bioactive intact molecule, at a subtilisin-like protein convertase (SPC) site, resulting in increased circulating FGF23 levels and hypophosphatemia; 2) mutations in DMP1 cause ARHR, not only by increasing serum FGF23, albeit by enhanced production and not limited cleavage, but also by limiting production of the active DMP1 component, the C-terminal fragment, resulting in dysregulated production of DKK1 and β-catenin, which contributes to impaired bone mineralization; and 3) mutations in PHEX cause XLH both by altering FGF23 proteolysis and production and causing dysregulated production of DKK1 and β-catenin, similar to abnormalities in ADHR and ARHR, but secondary to different central pathophysiological events. These discoveries indicate that ADHR, XLH, and ARHR represent three related heritable hypophosphatemic diseases that arise from mutations in, or dysregulation of, a single common gene product, FGF23 and, in ARHR and XLH, complimentary DMP1 and PHEX directed events that contribute to abnormal bone mineralization.This article is part of a Special Issue entitled "The Osteocyte".     

Cross sectional survey of Varicella-Zoster virus and measles seropositivity in people living with HIV in a Parisian suburb and a review of current immunization guidelines

According to evidence-based guidelines, vaccines against measles and varicella are generally recommended to susceptible HIV-positive patients, as long as they are not severely immunocompromised. However, routine screening to determine serologic status is not recommended. We conducted a seroprevalence study of anti-measles and anti-Varicella-Zoster virus (VZV) antibodies in adults living with HIV (PLWHA) consulting at Avicenne University Hospital in a Parisian suburb. Sera were collected in years 2018–2020 and tested by commercial immunoassays in 268 patients. Most of the patients were born in Sub-Saharan Africa (55 %) and only 23 % in Europe. Measles and varicella seropositivity were present respectively in 91.4 % and 96.2 % of patients. One patient in ten was seronegative to at least one of tested diseases. In the univariate analysis, only younger age (p = 0.027) was associated with a higher risk of measles seronegativity, while shorter time since arrival in France (p < 0.001) and shorter time since HIV discovery (p = 0.007) were associated with a higher risk of VZV seronegativity. In multivariate analysis no association was found. This study highlights the absence of specific risk factors for VZV and measles seronegativity in PLWHA and supports the importance of routine screening, in order to increase immunization rates and reduce risk of complications.     

Using the Barthel Index and modified Rankin Scale as Outcome Measures for Stroke Rehabilitation Trials; A Comparison of Minimum Sample Size Requirements

ObjectivesUnderpowered trials risk inaccurate results. Recruitment to stroke rehabilitation randomised controlled trials (RCTs) is often a challenge. Statistical simulations offer an important opportunity to explore the adequacy of sample sizes in the context of specific outcome measures. We aimed to examine and compare the adequacy of stroke rehabilitation RCT sample sizes using the Barthel Index (BI) or modified Rankin Scale (mRS) as primary outcomes.MethodsWe conducted computer simulations using typical experimental event rates (EER) and control event rates (CER) based on individual participant data (IPD) from stroke rehabilitation RCTs. Event rates are the proportion of participants who experienced clinically relevant improvements in the RCT experimental and control groups. We examined minimum sample size requirements and estimated the number of participants required to achieve a number needed to treat within clinically acceptable boundaries for the BI and mRS.ResultsWe secured 2350 IPD (18 RCTs). For a 90% chance of statistical accuracy on the BI a rehabilitation RCT would require 273 participants per randomised group. Accurate interpretation of effect sizes would require 1000s of participants per group. Simulations for the mRS were not possible as a clinically relevant improvement was not detected when using this outcome measure.ConclusionsStroke rehabilitation RCTs with large sample sizes are required for accurate interpretation of effect sizes based on the BI. The mRS lacked sensitivity to detect change and thus may be unsuitable as a primary outcome in stroke rehabilitation trials.     

Effects of the modified excision combined with bidirectional photodynamic therapy on refractory hidradenitis suppurativa: a retrospective study

Lasers in Medical Science - To describe the clinical features of refractory hidradenitis suppurativa (HS) patients (Hurley stageII and stage III) and evaluate the efficacy of combined treatment of...     

Cerebral arteriostenosis associated with elevated serum-immunoglobulin E level in young adults without risk factors for ischemic stroke: A possible manifestation of cerebral vasculitis?

We report a series of young adults with symptomatic cerebral arteriostenosis characterized by elevated serum immunoglobulin (Ig) E levels. All patients had no definite risk factors for cerebral vascular diseases. The clinical data of 26 young adults (age 18–50 years) with ischemic stroke, characterized only by increased serum IgE levels and without risk factors for cerebral vascular disease, were retrospectively reviewed. Arteriostenosis was surveyed and followed-up by digital subtraction angiography (DSA), and the stenosis rate was estimated using the warfarin–aspirin symptomatic intracranial disease technique. All patients were treated with corticosteroids according to the common strategy for vasculitis. There was no recurrent stroke during follow-up. The mean degree of stenosis before and after treatment was 69.3 ± 29.8% and 47.9 ± 45.1%, respectively. The difference of stenosis rates between initial and follow-up DSA evaluation was significant using a paired samples test (21.31 ± 26.88, 95% confidence interval [CI] 13.58–29.03, t = 5.55, p < 0.001). Kaplan–Meier survival analysis revealed that the 13-month cumulative improved lesion rate was 40.3 ± 8.7%. This remained the same at 18 months. The mean time to lesion improvement was 12.58 ± 0.96 months (95% CI 10.70–14.46) and median time was 13 ± 3.88 months (95% CI 5.39–20.61). To our knowledge, cerebral arteriostenosis with only elevated IgE serum levels has not been reported. Our data showed that corticosteroid treatment can achieve clinical and artery improvement. This suggests that the cerebral arteriostenosis seen in our study might be caused by some specific type of vessel inflammation.     

Immune checkpoint inhibitors combined with chemotherapy/bevacizumab therapy for patients with advanced lung cancer and heavily treated with EGFR mutation: a retrospective analysis

BackgroundEGFR-mutated lung cancer poorly responded to anti-programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) monotherapy. Whether patients with EGFR-mutated lung cancer can benefit from anti-PD-1/PD-L1 therapy combined with other drugs remains controversial. We retrospectively evaluated the safety and efficacy of the PD-1 inhibitor combined with other drugs (chemotherapy and/or bevacizumab) in patients with EGFR-mutated lung cancer, who have progressed on EGFR–TKI treatment to determine the activity of the anti-PD-1/PD-L1 therapy combined with chemotherapy or/and bevacizumab therapy in heavily treated patients with EGFR-mutated lung cancer.MethodsWe identified 56 patients with EGFR-mutated lung cancer treated with PD-1/PD-L1 inhibitors alone or combined with the chemotherapy/bevacizumab therapy. The objective response rates were assessed using RECIST v1.1. Adverse events (AEs) were graded in accordance with the National Cancer Institute Common Terminology Criteria for Adverse Events v4.0. The study was conducted in accordance with the Declaration of Helsinki (as revised in 2013). The study was approved by the Academic Ethics Committee of Jiangsu Cancer Hospital. (NO. 2019 160), and individual consent for this retrospective analysis was waived.ResultsObjective responses were observed in 6 of 56 (10.7%) patients, and the disease control rate was 53.6% (30/56). The median progression-free survival (PFS) was 3.33 months with 95% CI of 1.58–5.08 months. No patient achieved a complete response. All six patients that achieved PR were treated with the PD-1 inhibitor combined with chemotherapy or bevacizumab therapy. Three of the six patients who achieved PR were treated with radiotherapy combined with PD-1 inhibitor-based therapy. Patients treated with the PD-1 inhibitor-based therapy as second-line therapy showed relatively longer PFS and higher objective response rates than those treated with PD-1 inhibitor-based therapy as third- or late-line therapy (PFS: 5.50 vs. 3.27 months, P=0.301; objective response rates: 25.0% vs. 6.82%, P=0.071). No additional AE profile was observed.ConclusionsThe PD-1 inhibitor combined with the chemotherapy/bevacizumab therapy showed acceptable toxicity profile and moderate efficacy on heavily treated advanced EGFR-mutated lung cancer after the exhaustion of target therapy.     

Quality gaps in public pancreas imaging datasets: Implications & challenges for AI applications

ObjectiveQuality gaps in medical imaging datasets lead to profound errors in experiments. Our objective was to characterize such quality gaps in public pancreas imaging datasets (PPIDs), to evaluate their impact on previously published studies, and to provide post-hoc labels and segmentations as a value-add for these PPIDs.MethodsWe scored the available PPIDs on the medical imaging data readiness (MIDaR) scale, and evaluated for associated metadata, image quality, acquisition phase, etiology of pancreas lesion, sources of confounders, and biases. Studies utilizing these PPIDs were evaluated for awareness of and any impact of quality gaps on their results. Volumetric pancreatic adenocarcinoma (PDA) segmentations were performed for non-annotated CTs by a junior radiologist (R1) and reviewed by a senior radiologist (R3).ResultsWe found three PPIDs with 560 CTs and six MRIs. NIH dataset of normal pancreas CTs (PCT) (n = 80 CTs) had optimal image quality and met MIDaR A criteria but parts of pancreas have been excluded in the provided segmentations. TCIA-PDA (n = 60 CTs; 6 MRIs) and MSD(n = 420 CTs) datasets categorized to MIDaR B due to incomplete annotations, limited metadata, and insufficient documentation. Substantial proportion of CTs from TCIA-PDA and MSD datasets were found unsuitable for AI due to biliary stents [TCIA-PDA:10 (17%); MSD:112 (27%)] or other factors (non-portal venous phase, suboptimal image quality, non-PDA etiology, or post-treatment status) [TCIA-PDA:5 (8.5%); MSD:156 (37.1%)]. These quality gaps were not accounted for in any of the 25 studies that have used these PPIDs (NIH-PCT:20; MSD:1; both: 4). PDA segmentations were done by R1 in 91 eligible CTs (TCIA-PDA:42; MSD:49). Of these, corrections were made by R3 in 16 CTs (18%) (TCIA-PDA:4; MSD:12) [mean (standard deviation) Dice: 0.72(0.21) and 0.63(0.23) respectively].ConclusionSubstantial quality gaps, sources of bias, and high proportion of CTs unsuitable for AI characterize the available limited PPIDs. Published studies on these PPIDs do not account for these quality gaps. We complement these PPIDs through post-hoc labels and segmentations for public release on the TCIA portal. Collaborative efforts leading to large, well-curated PPIDs supported by adequate documentation are critically needed to translate the promise of AI to clinical practice.