Goldilocks, vitamin D and sarcoidosis

Osteoporotic bone fracture risk assessment in Latvian patients with newly diagnosed sarcoidosis

BACKGROUND AND AIM

Increased calcitriol synthesis in sarcoid granulomas with subsequent hypercalcaemia and hypercalciuria can affect bone metabolism in patients with sarcoidosis. Multiple factors can increase the fracture risk in patients with sarcoidosis. This study aimed to evaluate a 10-year osteoporotic and a 10-year hip fracture risk and to analyse factors affecting fracture risk for patients with newly diagnosed sarcoidosis compared to an age- and gender-matched control group from a real-world setting.

METHODS

The cross-sectional study included 171 patients with a histologically verified diagnosis of sarcoidosis who were hospitalised due to suspected sarcoidosis within two years and an age- and gender-matched control group of 178 hospitalised individuals. QFracture algorithm questions were asked during interviews.

RESULTS

A cohort of 349 subjects was analysed. The median age in the patient group was 40 years (IQR:20), and 60.2% were female. 21.6% of patients with sarcoidosis had at least one comorbidity that could potentially influence the osteoporotic fracture risk. Both the median 10-year osteoporotic fracture risk (0.9% (IQR:2) vs 1.3% (IQR:2.3), p=0.005; U=12394) and a 10-year hip fracture risk (0.1% (IQR:0.3) vs 0.2% (IQR:0.5), p=0.003; U=12368.5) was lower in patients with sarcoidosis compared to control group subjects. As compared to the control group, individuals with sarcoidosis exhibited a lower frequency of both osteoporotic (2.4% vs 11.2%, OR=0.189 (95% CI:0.063-0.566), p=0.003) and low-energy trauma fractures (2.9% vs 11.8%, OR=0.225 (95% CI:0.083-0.612), p=0.003) in personal medical history.

CONCLUSIONS

This was the first study to investigate osteoporotic fracture risk and related factors in Latvian patients with newly diagnosed sarcoidosis. Our data show a lower risk of a 10-year osteoporotic and a 10-year hip fracture risk in patients with sarcoidosis compared to age- and gender-matched control group subjects from a real-world setting.

The Power of Vitamin D: Is the Future in Precision Nutrition through Personalized Supplementation Plans?

In the last few decades, vitamin D has undeniably been one of the most studied nutrients. Despite our ability to produce vitamin D through sunlight exposure, its presence in several natural food sources and fortified foods, and its widespread availability as a dietary supplement, vitamin D deficiency is a serious public health problem, affecting nearly 50% of the global population. Low serum levels of vitamin D are being associated with increased susceptibility to numerous health conditions, including respiratory infections, mental health, autoimmune diseases, and different cancer types. Although the association between vitamin D status and health is well-established, the exact beneficial effects of vitamin D are still inconclusive and indefinite, especially when considering the prevention and treatment of different health conditions and the determination of an appropriate dosage to exert those beneficial effects in various population groups. Therefore, further research is needed. With constant improvements in our understanding of individual variations in vitamin D metabolism and requirements, in the future, precision nutrition and personalized supplementation plans could prove beneficial.

A Rare Case of Polymyositis and Systemic Sclerosis Overlap Syndrome: Diagnosis and Treatment

Diffuse scleroderma is a kind of scleroderma in which the immune system malfunctions, leading to excessive production of collagen in the skin and a variety of organ abnormalities. Based on previously recognized criteria, overlap syndrome is a disorder in which two or more medical illnesses are documented in a single patient. These syndromes are significantly more prevalent in illnesses with mixed connective tissue. In this case report, we present a patient with overlapping systemic sclerosis and polymyositis symptoms. The treatment and diagnosis of this extremely uncommon condition are discussed in further detail.

Renal sarcoidosis

Sarcoidosis is a systemic inflammatory disease of unknown etiology. The pathogenesis rests on an aberrant T cell response to unidentified antigens in individuals predisposed by genetic and environmental factors. Increased expression of polarized macrophages and disequilibrium between effector and regulator T cells contribute to the formation of noncaseating granulomas, that are frequently found in affected organs. The main kidney abnormalities in sarcoidosis are granulomatous interstitial nephritis (GIN) and hypercalcemia-related disorders. The clinical diagnosis is difficult. The outcome is variable, ranging from spontaneous remission to end-stage kidney disease (ESKD). Early diagnosis and prompt treatment with corticosteroids can improve the prognosis. Hypercalcemia may be responsible for acute kidney injury (AKI) caused by vasoconstriction of afferent arterioles. Complications of persistent hypercalcemia include nephrocalcinosis and renal stones. In patients with ESKD, dialysis and transplantation can offer results comparable to those observed in patients with other causes of kidney failure. Based on a review of the literature, we present an overview of the etiopathogenesis, the renal manifestations of sarcoidosis and their complications, management and prognosis.

Information Theory as an Experimental Tool for Integrating Disparate Biophysical Signaling Modules

There is a growing appreciation in the fields of cell biology and developmental biology that cells collectively process information in time and space. While many powerful molecular tools exist to observe biophysical dynamics, biologists must find ways to quantitatively understand these phenomena at the systems level. Here, we present a guide for the application of well-established information theory metrics to biological datasets and explain these metrics using examples from cell, developmental and regenerative biology. We introduce a novel computational tool named after its intended purpose, calcium imaging, (CAIM) for simple, rigorous application of these metrics to time series datasets. Finally, we use CAIM to study calcium and cytoskeletal actin information flow patterns between Xenopus laevis embryonic animal cap stem cells. The tools that we present here should enable biologists to apply information theory to develop a systems-level understanding of information processing across a diverse array of experimental systems.

Serum and urinary calcium level in Latvian patients with sarcoidosis

Objectives

Sarcoidosis is a multisystem granulomatous disease of unknown etiology that in 90% of cases affects the lungs. Calcium metabolism testing can be useful in diagnostics. The aim of the study was to assess the correlation between calcium metabolism and sarcoidosis form of manifestation/demographic indicators.

Material and methods

In a retrospective study medical records of all patients (n = 699) who had been hospitalized with suspected sarcoidosis in a specialized clinic of Riga Eastern Clinical University Hospital during the period from January 1^st, 2013 until December 31^st, 2014 were analyzed. Further analysis included only patients with histologically and/or clinically confirmed sarcoidosis (n = 281).

Results

Patients’ average age at the time of diagnosis was 39 ±13 years. Elevated serum calcium was observed in 9.9% of cases. A statistically significant correlation was found between serum calcium and age (p < 0.01). There was an association between serum calcium and gender (p < 0.05) – levels were higher in men (2.43 mmol/l) than in women (2.40 mmol/l). Elevated calcium in 24-hour urine was observed in 22.7% of patients. The mean value was 232.3 mg/24 h, levels were higher in men (258.7 mg/24 h) than in women (202.3 mg/24 h), and the association with gender was statistically significant (p < 0.01).

Conclusions

We can conclude that in Latvia sarcoidosis affects mostly young and middle-aged people. Both serum calcium and calcium in 24-hour urine are important parameters for sarcoidosis diagnostics. Hypercalcemia was found in 9.9% of patients, hypercalciuria in 22.7% of patients, and both were statistically significantly higher in men, regardless of age.

Malakoplakia as a cause of severe hypercalcemia through ectopic 25-hydroxyvitamin D3 1-alpha-hydroxylase expression: A case report

RATIONALE

Malakoplakia is a rare disease characterized by the presence of nongranulomatous macrophage infiltration. In most cases, it affects the urinary tract. Malakoplakia can cause acute kidney injury when it is localized in the kidneys.

PATIENT CONCERNS

Here, we report the case of a 65-year-old female patient with renal malakoplakia responsible for hypercalcemia. During her initial assessment, she was also diagnosed 25-OH vitamin D insufficiency, for which she was prescribed oral cholecalciferol. Three months later, she developed severe hypercalcemia with normal 25-OH vitamin D and parathyroid hormone levels and high 1,25-dihydroxyvitamin D levels.

DIAGNOSES

After a superimposed granulomatous disease was excluded, malakoplakia cells were suspected to be responsible for the abnormal 25-hydroxyvitamin D3 1-alpha-hydroxylase activity, which was confirmed by immunohistochemistry.

INTERVENTIONS

Cholecalciferol was stopped, the patient was rehydrated with intravenous physiological saline, and prednisone was initiated to decrease the enzyme activity.

OUTCOMES

Six months later, she displayed normal serum calcium, 25-OH vitamin D and 1,25-dihydroxyvitamin D levels.

LESSONS

This case illustrates that malakoplakia may exhibit ectopic 25-hydroxyvitamin D3 1-alpha-hydroxylase activity and cause severe hypercalcemia upon vitamin D supplementation. Therefore, such supplementation should not be given in malakoplakia patients without an actual deficiency and requires careful monitoring of serum calcium.

A functional proteomics approach to the comprehension of sarcoidosis

Pulmonary sarcoidosis (Sar) is an idiopathic disease histologically typified by non-caseating epitheliod cell sarcoid granulomas. A cohort of 37 Sar patients with chronic persistent pulmonary disease was described in this study. BAL protein profiles from 9 of these Sar patients were compared with those from 8 smoker (SC) and 10 no-smoker controls (NSC) by proteomic approach. Principal Component Analysis was performed to clusterize the samples in the corresponding conditions highlighting a differential pattern profiles primarily in Sar than SC. Spot identification reveals thirty-four unique proteins involved in lipid, mineral, and vitamin Dmetabolism, and immuneregulation of macrophage function. Enrichment analysis has been elaborated by MetaCore, revealing 14-3-3ε, α1-antitrypsin, GSTP1, and ApoA1 as "central hubs". Process Network as well as Pathway Maps underline proteins involved in immune response and inflammation induced by complement system, innate inflammatory response and IL-6signalling. Disease Biomarker Network highlights Tuberculosis and COPD as pathologies that share biomarkers with sarcoidosis. In conclusion, Sar protein expression profile seems more similar to that of NSC than SC, conversely to other ILDs. Moreover, Disease Biomarker Network revealed several common features between Sar and TB, exhorting to orientate the future proteomics investigations also in comparative BALF analysis of Sar and TB.

Endogenous gradients of resting potential instructively pattern embryonic neural tissue via Notch signaling and regulation of proliferation

Biophysical forces play important roles throughout embryogenesis, but the roles of spatial differences in cellular resting potentials during large-scale brain morphogenesis remain unknown. Here, we implicate endogenous bioelectricity as an instructive factor during brain patterning in Xenopus laevis. Early frog embryos exhibit a characteristic hyperpolarization of cells lining the neural tube; disruption of this spatial gradient of the transmembrane potential (Vmem) diminishes or eliminates the expression of early brain markers, and causes anatomical mispatterning of the brain, including absent or malformed regions. This effect is mediated by voltage-gated calcium signaling and gap-junctional communication. In addition to cell-autonomous effects, we show that hyperpolarization of transmembrane potential (Vmem) in ventral cells outside the brain induces upregulation of neural cell proliferation at long range. Misexpression of the constitutively active form of Notch, a suppressor of neural induction, impairs the normal hyperpolarization pattern and neural patterning; forced hyperpolarization by misexpression of specific ion channels rescues brain defects induced by activated Notch signaling. Strikingly, hyperpolarizing posterior or ventral cells induces the production of ectopic neural tissue considerably outside the neural field. The hyperpolarization signal also synergizes with canonical reprogramming factors (POU and HB4), directing undifferentiated cells toward neural fate in vivo. These data identify a new functional role for bioelectric signaling in brain patterning, reveal interactions between Vmem and key biochemical pathways (Notch and Ca(2+) signaling) as the molecular mechanism by which spatial differences of Vmem regulate organogenesis of the vertebrate brain, and suggest voltage modulation as a tractable strategy for intervention in certain classes of birth defects.