Current concepts regarding calcium metabolism and bone health in sarcoidosis

Kidney manifestations of sarcoidosis

Renal involvement is a clinically relevant organ manifestation of sarcoidosis, leading to increased morbidity and complications. Although the exact incidence remains unknown, renal disease is likely to occur in up to one third of all sarcoidosis patients. Every patient with newly diagnosed sarcoidosis should receive a renal work-up and screening for disrupted calcium metabolism. Amid various forms of glomerulonephritis, granulomatous interstitial nephritis is the most common one, but it rarely leads to renal impairment. Histologically, granulomas can be absent. Nephrocalcinosis and nephrolithiasis are frequent forms when hypercalcaemia or hypercalciuria occur. Drugs used for treatment of systemic sarcoidosis can also cause renal damage. Due to its high heterogeneity, renal sarcoidosis can be difficult to treat. Glucocorticoids and various immunosuppressive treatments have been proven to be effective based on case series, but clinical trials are lacking. A treatment guideline for renal sarcoidosis is urgently needed. In this review article, we present an overview of the different forms of renal sarcoidosis and the diagnostic steps to confirm renal involvement; in addition, we provide insights on the management and available treatments. A better understanding regarding the pathogenesis of sarcoidosis is the key for the development of more specific, targeted therapies.

Sarcoidosis with musculoskeletal manifestations: systematic review of non-pharmacological and pharmacological treatments

We aimed to summarise effects and use of non-pharmacological and pharmacological treatments for sarcoidosis with musculoskeletal manifestations. We systematically searched the Cochrane Library, Ovid MEDLINE, Embase, CINAHL, AMED, Scopus, clinical.trials.gov, PROSPERO and PEDro for systematic reviews from 2014 to 2022 and for primary studies from date of inception to March 29, 2022, and studies with patients diagnosed with sarcoidosis with musculoskeletal manifestations. Inclusion criteria required that studies reported effects of non-pharmacological and/or pharmacological treatments or number of patients receiving these treatments. Results were reported narratively and in forest plots. Eleven studies were included. No systematic reviews fulfilled our inclusion criteria. None of the included studies had a control group. We found that between 23 and 100% received corticosteroids, 0-100% received NSAIDs, 5-100% received hydroxychloroquine, 12-100% received methotrexate, 0-100% received TNF inhibitors, and 3-4% received azathioprine. Only ten patients in one study had used non-pharmacological treatments, including occupational therapy, chiropractic and acupuncture. There are no controlled studies on treatment effects for patients with sarcoidosis with musculoskeletal manifestations. We found 11 studies reporting use of pharmacological treatments and only one study reporting use of non-pharmacological treatments. Our study identified major research gaps for pharmacological and non-pharmacological treatment in musculoskeletal sarcoidosis and warrant randomised clinical trials for both.

State-of-the-Art Treatments for Sarcoidosis

Sarcoidosis is a heterogeneous disease with various treatment indications. Although it affects mainly the lungs, sarcoidosis can affect every organ, especially when the disease course is chronic and protracted. Regular patient follow-up is recommended for early recognition of active, ongoing organ-specific granulomatous inflammation to avoid progression to irreversible fibrosis. In this review, we elaborate on treatment indications and various anti-sarcoidosis regimens proven useful in clinical trials. We also review specialized treatment of specific disease manifestations, with a focus on cardiac sarcoidosis. We also report on treatment for special conditions such as fatigue and small fiber neuropathy. Treatment for sarcoidosis is an emerging landscape, with new data complementing the existing knowledge.

Musculoskeletal Manifestations of Sarcoidosis

Since its initial description in the late 19th century, sarcoidosis has been extensively studied. Although the general mechanism of immune activation is known, many details especially in the context of disease associations are still missing. One of such associations is the musculoskeletal complications that are widely variable in terms of presentation and response to treatment. Sarcoidosis can involve the joints leading to acute and, less commonly chronic, arthritis. While acute arthritis is mostly self-resolving in nature, chronic arthritis may lead to deformity and destruction of the joint. Sarcoidosis can also involve the muscles, leading to different pathologies primarily categorized according to the clinical presentation, despite the efforts to find a new classification based on imaging, histological, and clinical findings. The bones can be directly and indirectly affected. Different types of bone lesions have been described, although around half of these patients remain asymptomatic. Osteoporosis, increased risk of fractures, hypercalcemia, and hypercalciuria are examples of the indirect effect of sarcoidosis on the bones, possibly contributed to elevated levels of calcitriol. Nevertheless, sarcoidosis can be associated with small-vessel, medium-vessel, and large vessel vasculitis, although it is frequently difficult to differentiate between the co-existence of a pure vasculitis and sarcoidosis and sarcoid vasculitis.

How to Tackle the Diagnosis and Treatment in the Diverse Scenarios of Extrapulmonary Sarcoidosis

Extrapulmonary sarcoidosis occurs in 30–50% of cases of sarcoidosis, most often in association with pulmonary involvement, and virtually any organ can be involved. Its incidence depends according to the organs considered, clinical phenotype, and history of sarcoidosis, but also on epidemiological factors like age, sex, geographic ancestry, and socio-professional factors. The presentation, symptomatology, organ dysfunction, severity, and lethal risk vary from and to patient even at the level of the same organ. The presentation may be specific or not, and its occurrence is at variable times in the history of sarcoidosis from initial to delayed. There are schematically two types of presentation, one when pulmonary sarcoidosis is first discovered, the problem is then to detect extrapulmonary localizations and to assess their link with sarcoidosis, while the other presentation is when extrapulmonary manifestations are indicative of the disease with the need to promptly make the diagnosis of sarcoidosis. To improve diagnosis accuracy, extrapulmonary manifestations need to be known and a medical strategy is warranted to avoid both under- and over-diagnosis. An accurate estimation of impairment and risk linked to extrapulmonary sarcoidosis is essential to offer the best treatment. Most frequent extrapulmonary localizations are skin lesions, arthritis, uveitis, peripheral lymphadenopathy, and hepatic involvement. Potentially severe involvement may stem from the heart, nervous system, kidney, eye and larynx. There is a lack of randomized trials to support recommendations which are often derived from what is known for lung sarcoidosis and from the natural history of the disease at the level of the respective organ. The treatment needs to be holistic and personalized, taking into account not only extrapulmonary localizations but also lung involvement, parasarcoidosis syndrome if any, symptoms, quality of life, medical history, drugs contra-indications, and potential adverse events and patient preferences. The treatment is based on the use of anti-sarcoidosis drugs, on treatments related to organ dysfunction and supportive treatments. Multidisciplinary discussions and referral to sarcoidosis centers of excellence may be helpful for difficult diagnosis and treatment decisions.

A Comprehensive Review of Sarcoidosis Treatment for Pulmonologists

Due to frequent lung involvement, the pulmonologist is often the reference physician for management of sarcoidosis, a systemic granulomatous disease with a heterogeneous course. Treatment of sarcoidosis raises some issues. The first challenge is to select patients who are likely to benefit from treatment, as sarcoidosis may be self-limiting and remit spontaneously, in which case treatment can be postponed and possibly avoided without any significant impact on quality of life, organ damage or prognosis. Systemic glucocorticosteroids (GCs) are the drug of first choice for sarcoidosis. When GCs are started, there is a > 50% chance of long-term treatment. Prolonged use of prednisone at > 10 mg/day or equivalent is often associated with severe side effects. In these and refractory cases, steroid-sparing options are advised. Antimetabolites, such as methotrexate, are the second-choice therapy. Biologics, such as anti-TNF and especially infliximab, are third-choice drugs. The three treatments can be used concomitantly. Regardless of whether treatment is started, the clinician needs to organize regular follow-up to monitor remissions, flares, progression, complications, toxicity and relapses in order to promptly adjust the drugs used.

Toll-like receptors 2 expression in mediastinal lymph node of patients with sarcoidosis

Background

Toll-like receptors (TLRs) play a vital role as a first defense mechanism linking the innate with the adaptive immune system. Prior studies showed that TLR2 participated in immune responses of sarcoidosis. However, the role of TLR2 in the progression of mediastinal lymph nodes associated with sarcoidosis is still unknown. The current study aims to investigate the expression of Toll-like receptors 2 (TLR2) in mediastinal lymph nodes of patients with sarcoidosis.

Methods

Mediastinal lymph nodes biopsy specimens were collected from 10 patients with sarcoidosis and 11 normal controls. The expression of TLR2 in mediastinal lymph nodes was detected by immunohistochemistry.

Results

In mediastinal lymph nodes specimens, immunohistochemical examination revealed that expression of TLR2 could be detected in sarcoidosis patients, while it was scarcely detected in the mediastinal lymph nodes of control. The mean optical density of TLR2 in mediastinal lymph nodes of sarcoidosis was significantly higher than controls (124.9±24.3 vs. 92.6±35.2, P=0.026). Among patients with sarcoidosis, correlation analysis showed that the mean optical density of TLR2 in mediastinal lymph nodes positively correlated with the level of 24-hour urinary calcium (R=0.781, P=0.038).

Conclusions

The expression of TLR2 was upregulated in mediastinal lymph nodes of sarcoidosis patients. The expression of TLR2 in mediastinal lymph nodes was associated with the level of 24-hour urinary calcium, suggesting that TLR2 might become another predictor of disease activity.

Hypercalciuria in Sarcoidosis: A Specific Biomarker With Clinical Utility

Background: Changes in calcium metabolism are quite common in sarcoidosis: hypercalciuria is linked to a persistent clinical phenotype and more active disease. No data is yet available on the specificity of parameters of calcium metabolism as biomarkers for distinguishing different chronic interstitial lung diseases (ILD). Here we assessed calcium metabolism in an Italian population of sarcoidosis patients, which included a group with stage IV fibrotic disease, and compared the results with those of idiopathic pulmonary fibrosis (IPF) and chronic hypersensitivity pneumonitis (cHP) patients.

Population and Methods: We recruited sarcoidosis, IPF and cHP patients retrospectively. All patients were diagnosed through multidisciplinary discussion and were monitored at the Regional ILD Referral Centre in Siena. Clinical, radiological, functional, immunological and laboratory parameters were collected and entered in an electronic database for data analysis.

Results: A total of 305 patients (237 sarcoidosis, 40 IPF and 28 cHP) were enrolled. Sarcoidosis patients included a predominance of females and were significantly younger than IPF and cHP patients (p < 0.0001 for both). In the sarcoidosis population, 17 patients (7.2%) showed radiological evidence of lung fibrosis, according the Scadding classification; fibrotic disease was also confirmed by CT scan. Concerning calcium metabolism, sarcoidosis patients showed significantly higher serum and urinary concentrations of calcium than IPF and cHP patients (p = 0.0004 and p < 0.0001, respectively). These findings were also confirmed when comparing groups with fibrotic sarcoidosis, IPF and cHP (p = 0.0237 and p = 0.0138). According to receiver operating characteristics (ROC) curve analysis, urinary calcium showed better diagnostic accuracy than serum calcium in discriminating sarcoid and non-sarcoid lung fibrosis (AUC 0.7658 vs. 0.6205; p = 0.0026 vs. p = 0.1820).

Discussion: Our results confirmed that changes in calcium metabolism, particularly hypercalciuria, occur in a substantial percentage of patients with sarcoidosis. Higher serum and urinary concentrations of calcium were found than in IPF and cHP; the same results were observed when the comparison was limited to patients with fibrotic sarcoidosis, supporting the hypothesis that dysregulation of calcium metabolism may be a special feature of sarcoid granulomas. Hypercalciuria distinguished fibrotic sarcoidosis from IPF and cHP, suggesting that assessment of calcium metabolism may be useful in the diagnostic pathway of ILDs.

Balancing Altered Calcium Metabolism with Bone Health in Sarcoidosis

Abnormal calcium metabolism in sarcoidosis patients can lead to hypercalcemia, hypercalciuria, and kidney stones. Hypercalcemia in sarcoidosis is usually due to increased activity of 1α-hydroxylase in macrophages of pulmonary granulomata, resulting in low levels of 25-hydroxyvitamin D and high levels of calcitriol. Vitamin D supplementation may be dangerous for some sarcoidosis patients and is recommended only for those with decreased 25-hydroxyvitamin D and reduced or normal calcitriol level. Diagnosis, treatment of osteoporosis, and maintenance of bone health are complex issues for sarcoidosis patients. An approach to diagnosis and treatment of bone fragility is presented.

Osseous manifestations of sarcoidosis

Sarcoidosis is a systemic multisystem inflammatory disease of unknown etiology. The disease is characterized by formation of non-caseating granulomas. The most common presentation is bilateral hilar lymphadenopathy and lung infiltration, but the disease is very heterogeneous, with an unpredictable clinical course. Musculoskeletal manifestations are common. Bone involvement is less frequent, and usually occurs in patients with chronic multisystem course of the disease. They are most commonly found in the phalanges of hands and feet, and are usually bilateral. The skull, long bones, ribs, pelvis, and axial skeleton may also be affected. Osseous involvement may be asymptomatic but in some cases can cause a severe disability. Imaging techniques are important for diagnosis. Radiological investigations revealed sclerotic or destructive lesions (involving also joints), cystic and punched out lesions and cortical abnormalities. Biopsy is required for differential diagnosis with respect to malignancy. Treatment is a part of systemic therapy and is not needed in all cases. Glucocorticoids and TNF-α antagonists are used for management.

Advanced sarcoidosis

PURPOSE OF REVIEW

Advanced sarcoidosis is an important cause of morbidity and mortality in sarcoidosis. Over the past few years, several studies have been published clarifying the prevalence and severity of this condition.

RECENT FINDINGS

Pulmonary involvement is the most common form of sarcoidosis. Increased morbidity and significant mortality is encountered in advanced lung disease. Although many sarcoidosis patients with pulmonary fibrosis have a normal life expectancy, at least 20% develop progression and may die from this complication. Sarcoidosis-associated pulmonary hypertension (SAPH) is an independent cause of death in advanced pulmonary sarcoidosis. Two large multicenter registries and a large single-center report provide more details regarding presentation and outcome of SAPH. Advanced neurologic disease is associated with significant morbidity, but not much mortality. Two large retrospective reviews demonstrated the effectiveness of infliximab in treating advanced neurosarcoidosis. Advanced cardiac sarcoidosis can lead to mortality.

SUMMARY

Advanced sarcoidosis is associated with significant morbidity and some mortality. Up to a quarter of all sarcoidosis patients have one or more forms of advanced disease. These patients require closer monitoring and often multiples treatments.

Sarcoidosis-associated hypercalcemia potentiating calcific uremic arteriolopathy in a patient with a left ventricular assist device

Calcific uremic arteriolopathy is a rare, life-threatening syndrome of vascular calcification characterized by occlusion of microvessels that results in extremely painful skin necrosis. We present a case of sarcoidosis-associated hypercalcemia potentiating calcific uremic arteriolopathy in a patient with a left ventricular assist device. The patient's calcific uremic arteriolopathy was successfully treated with sodium thiosulfate. Clinicians should be vigilant in diagnosing calcific uremic arteriolopathy early since it is especially life-threatening in patients with multiple risk factors.

Retrospective Study of Factors Potentially Influencing Occurrence of Cough in Slovak Patients with Sarcoidosis

Introduction

Sarcoidosis is a multisystem granulomatous disease of unknown aetiology, commonly involving the lungs.  Cough is a frequent and troublesome symptom of sarcoidosis that reduces patients' quality of life.

Aim

Retrospective analysis of different factors—smoking history, Scadding stage, results of lung function testing, calcium metabolism, endobronchial finding, CD4+/CD8+ T-cell ratio in bronchoalveolar lavage fluid (BALF), and other sarcoidosis symptoms in relationship to presence/absence of cough in sarcoidosis patients.

Methods

We retrospectively studied sarcoidosis patients diagnosed at the Clinic of Pneumology and Phthisiology of Martin University Hospital between 1998 and 2018. Patients with a history of cough-relevant comorbidities were excluded from the study. GraphPad Prism 7.0 software was used to perform statistical analysis.

Results

101 sarcoidosis patients were included to the study: 65 patients reporting from cough and 36 without cough. The cough was slightly more frequent in nonsmokers (p=0.166) and in women (p=0.688). Cough was associated with dyspnoea (p=0.0007), fever (p=0.0324), and chest pain (p=0.0206) and did not associate with arthralgia (p=0.317) and erythema nodosum (p=0.505). Patients with cough had significantly a lower average value of calciuria (p=0.0014) and lower MEF25 (p=0.0304), MEF50 (p=0.0061), FEV1 (p=0.0025), and FVC (p=0.0025) in % of predicted values, and more often positive endobronchial finding (p=0.0206), compared to patients without cough. Calcemia, FEV1/FVC, DLCO, and CD4+/CD8+ T-cell ratio in BALF and occurrence of cough did not differ between different stages of the disease.

Conclusions

We found significant differences between sarcoidosis patients with/without cough regarding symptoms, results of lung function tests, endobronchial finding, and calcium metabolism. Further research is needed to understand the etiopathogenesis of cough in sarcoidosis patients.

Sarcoidosis and autoimmune diseases: differences, similarities and overlaps

PURPOSE OF REVIEW

Sarcoidosis is a rare, multisystem granulomatous disease of incompletely understood pathogenesis. Clinically, it shares common features with several systemic and organ-specific autoimmune diseases, although known autoantibodies or useful serologic markers for diagnosis and monitoring of disease activity are lacking. Sarcoidosis can both coexist with or mimic connective tissue diseases or vasculitis. Here, we review possible common etiologic factors between sarcoidosis and autoimmune disease, comparing clinical, laboratory and imaging features.

RECENT FINDINGS

Autoimmune diseases may precede or follow the diagnosis of sarcoidosis. Overall, the prevalence of both co-existing is unknown because of limited evidence. The presence of autoantibodies in sarcoidosis should raise suspicion of an underlying autoimmune disease that mimics or co-occurs with sarcoidosis. Silica dust exposure has been associated with an increased prevalence of both sarcoidosis and rheumatoid arthritis. In another study, autoimmune thyroid disease, Sjogren's syndrome and ankylosing spondylitis have been reported to be more frequent in sarcoidosis compared with healthy controls.

SUMMARY

A systematic diagnostic work-up is necessary to detect overlapping disease features in patients with sarcoidosis. Immune-modulating therapies need to be taken into account as these can induce paradoxical reactions.

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.

Sarcoidosis: a review for the internist

Sarcoidosis is a systemic granulomatous lung disease of unknown origin affecting people of any age, mainly young adults. The disease is extremely heterogeneous with an unpredictable clinical course. Different phenotypes have been identified: an acute syndrome can be distinguished from subacute and chronic variants. About 20% of patients are chronically progressive and may develop lung fibrosis. Sarcoidosis usually involves the lungs and thoracic lymph nodes, although the skin, eyes, bones, liver, spleen, heart, upper respiratory tract and nervous system can also be affected. No reliable indicators of clinical outcome are available, and there is no single serological biomarker with demonstrated unequivocal diagnostic and prognostic value. Diagnosis requires histological confirmation although a presumptive diagnosis may be acceptable in special conditions. This review examines the diagnostic approach to sarcoidosis involving a multidisciplinary team of specialists in which the internist has the task of identifying all pulmonary and extrapulmonary localizations of the disease and of managing complications and comorbidities.

Metabolic Disorders in Chronic Lung Diseases

Chronic lung diseases represent complex diseases with gradually increasing incidence, characterized by significant medical and financial burden for both patients and relatives. Their increasing incidence and complexity render a comprehensive, multidisciplinary, and personalized approach critically important. This approach includes the assessment of comorbid conditions including metabolic dysfunctions. Several lines of evidence show that metabolic comorbidities, including diabetes mellitus, dyslipidemia, osteoporosis, vitamin D deficiency, and thyroid dysfunction have a significant impact on symptoms, quality of life, management, economic burden, and disease mortality. Most recently, novel pathogenetic pathways and potential therapeutic targets have been identified through large-scale studies of metabolites, called metabolomics. This review article aims to summarize the current state of knowledge on the prevalence of metabolic comorbidities in chronic lung diseases, highlight their impact on disease clinical course, delineate mechanistic links, and report future perspectives on the role of metabolites as disease modifiers and therapeutic targets.