Urinary 8-Hydroxy-2'-Deoxyguanosine as a Myocardial Oxidative Stress Marker Is Associated With Ventricular Tachycardia in Patients With Active Cardiac Sarcoidosis.

BACKGROUND: Recently, we reported that urinary 8-hydroxy-2'-deoxyguanosine (U-8-OHdG), an oxidative stress marker, reflected inflammatory activity in cardiac sarcoidosis (CS). Here, we investigated whether U-8-OHdG levels were associated with ventricular tachycardia (VT) in patients with CS. METHODS AND RESULTS: This prospective cohort study enrolled 62 consecutive patients with CS, of whom 36 were diagnosed as having active CS based on abnormal 18F-flurodeoxyglucose accumulation in the heart on positron-emission tomography/computed tomography. The 36 patients with active CS were subdivided as having CS with sustained VT (CS-VT group; n=18) or CS without sustained VT (CS-nVT group; n=18). Twenty-seven patients diagnosed with idiopathic dilated cardiomyopathy served as heart failure controls. U-8-OHdG, brain natriuretic peptide, cardiac function indices, and immunohistological data from subendomyocardial biopsy samples were compared across groups. Immunohistochemical examination of ventricle biopsy samples revealed that the anti-8-OHdG antibody-positive area of cardiac tissue was significantly greater in CS-VT than in CS-nVT or dilated cardiomyopathy and significantly correlated with U-8-OHdG levels (n=58; R=0.61; P<0.00001), which were significantly higher in CS-VT than in CS-nVT (24.6±7.1 versus 15.2±3.8 ng/mg·Cr; P<0.0001). Other baseline characteristics did not differ between the groups. Multivariate analysis indicated that U-8-OHdG was an independent determinant factor for VT. Receiver operating characteristic curve analysis to identify patients with VT resulted in a U-8-OHdG cutoff value of 17.5 ng/mg·Cr (sensitivity, 89%; specificity, 83%; area under the curve, 0.90). CONCLUSIONS: U-8-OHdG levels are associated with VT in patients with active CS diagnosed by 18F-flurodeoxyglucose positron-emission tomography, providing additive and relevant information about the arrhythmia substrate.

An oxidative stress biomarker, urinary 8-hydroxy-2'-deoxyguanosine, predicts cardiovascular-related death after steroid therapy for patients with active cardiac sarcoidosis.

BACKGROUND: We investigated whether urinary 8-hydroxy-2'-deoxyguanosine (U-8-OHdG), a marker of oxidative DNA damage, is a prognosticator of cardiovascular-related death in patients with cardiac sarcoidosis (CS). METHODS AND RESULTS: In this prospective study, 30 consecutive patients were divided into the active CS (n=20) and non-active CS (n=10) groups, based on abnormal isotope accumulation in the heart on (18)F-fluorodeoxyglucose positron-emission tomography/computed tomography ((18)F-FDG PET/CT) imaging. Nineteen patients in the active CS group underwent corticosteroid therapy. Before corticosteroid therapy initiation, U-8-OHdG, brain natriuretic peptide (BNP), other biomarkers, and indices of cardiac function were measured. Patients were followed-up for a median of 48months. The primary endpoint was the incidence of cardiovascular-related death. During the follow-up period, in the corticosteroid-treated active CS group, 7 of 19 patients experienced cardiovascular-related death. By contrast, in the non-active CS group, 1 of 10 patients died from cardiovascular-related causes. Univariate and multivariate analyses showed that U-8-OHdG and BNP were independent predictors for cardiovascular-related death. The cut-off values for predicting cardiovascular death in corticosteroid-treated patients with active CS were 19.1ng/mg·Cr and 209pg/mL for U-8-OHdG and BNP, respectively. Patients with a U-8-OHdG concentration ≥19.1ng/mg·Cr or a BNP concentration ≥209pg/mL had a significantly higher cardiovascular-related death risk, but U-8-OHdG had better predictive value compared with BNP. CONCLUSION: These findings suggested that U-8-OHdG was a powerful predictor of cardiovascular-related death in patients with CS, suggesting that active CS patients with elevated U-8-OHdG levels might be resistant to corticosteroid therapy.

Vitamin-D status and mineral metabolism in two ethnic populations with sarcoidosis.

Vitamin-D insufficiency and sarcoidosis are more common and severe in African Americans (AA) than Caucasians. In sarcoidosis, substrate-dependent extrarenal 1,25-dihydroxyvitamin-D (1,25-(OH)2D) production is thought to contribute to hypercalciuria and hypercalcemia, and vitamin-D repletion is often avoided. However, the anti-inflammatory properties of vitamin-D may also be beneficial. We prospectively examined serum vitamin-D levels, calcium balance, and the effects of vitamin-D repletion in 86 AA and Caucasian patients with biopsy-proven active sarcoidosis from the USA (US) and Italy (IT) in university-affiliated outpatient clinics. Clinical features, pulmonary function, and calciotropic hormones were measured. 16 patients with vitamin-D deficiency and normal serum ionized calcium (Ca(2+)) were treated with oral ergocalciferol (50,000 IU/week) for 12 weeks. Baseline mineral parameters were similar in US (93% AA) and IT (95% Caucasian) patients irrespective of glucocorticoid treatment. Pulmonary dysfunction was less pronounced in IT patients. Nephrolithiasis (in 11% US, 17% IT patients) was associated with higher urinary calcium excretion. Vitamin-D deficiency was not more prevalent in patients compared to the respective general populations. As serum 25-hydroxyvitamin-D (25-OHD) rose postrepletion, serum 1,25-(OH)2D, γ-globulins, and the previously elevated angiotensin converting enzyme (ACE) levels declined. Asymptomatic reversible increases in Ca(2+) or urinary calcium/creatinine (Ca/Cr) developed in three patients during repletion. In conclusion, Caucasian and AA patients show similar calcium and vitamin D profiles. The higher prevalence of hypercalciuria and nephrolithiasis in sarcoidosis is unrelated to endogenous vitamin-D levels. Vitamin-D repletion in sarcoidosis is generally safe, although calcium balance should be monitored. A hypothesis that 25-OHD repletion suppresses granulomatous immune activity is provided.

Urinary 8-hydroxy-2'-deoxyguanosine as a novel biomarker of inflammatory activity in patients with cardiac sarcoidosis.

BACKGROUND: Inflammation and oxidative stress play a crucial role in the pathogenesis of cardiac sarcoidosis (SAR). We investigated whether urinary (U) 8-hydroxy-2'-deoxyguanosine (8-OHdG)--an oxidative DNA damage marker--was related to SAR inflammatory activity. METHODS: U-8-OHdG levels were measured in 31 SAR patients, classified as active (n=17) or non-active (n=14) based on (18)F-fluorodeoxyglucose positron emission tomography-computed tomography ((18)F-FDG-PET/CT), 28 dilated cardiomyopathy (DCM) patients, and 30 controls. In active SAR patients, U-8-OHdG levels were reexamined and compared with (18)F-FDG-PET/CT results at 6 months after corticosteroid treatment to assess therapeutic response. RESULTS: Immunohistochemical examination of left ventricle (LV) autopsy samples from SAR patients revealed positive 8-OHdG staining in cardiomyocyte nuclei from LV sections showing (18)F-FDG accumulation on PET/CT, while serum 8-OHdG levels were significantly higher in the coronary sinus than in the aortic root only in active SAR patients. U-8-OHdG levels in SAR patients were higher than those in controls, and significantly higher in active SAR patients than in non-active SAR and DCM patients. U-8-OHdG was a powerful predictor of active SAR in receiver operating characteristic curve analysis (AUC, 0.98; 95% CI, 0.94-1.02; optimal cutoff value, 13.1 ng/mg creatinine), with a sensitivity of 88.2% and a specificity of 92.9%. U-8-OHdG levels in responders significantly decreased at 6 months after corticosteroid treatment initiation, in proportion with the decrease in the focal cardiac uptake of (18)F-FDG. CONCLUSIONS: U-8-OHdG is a potentially clinically useful biomarker for evaluating inflammatory activity and monitoring the effectiveness of corticosteroid therapy in SAR patients.

Coexisting primary hyperparathyroidism and sarcoidosis cause increased angiotensin-converting enzyme and decreased parathyroid hormone and phosphate levels.

CONTEXT: Primary hyperparathyroidism (PHPT) and sarcoidosis may separately contribute to abnormal calcium and phosphate metabolism via different mechanisms, and their coexistence is infrequently reported. OBJECTIVE: We sought to characterize a group of 50 patients with coexisting PHPT and sarcoidosis in our institution to evaluate their clinical and laboratory characteristics. DESIGN AND SETTING: This was a retrospective observational study of patients with both disorders at our institution between January 1980 and December 2011. OUTCOME: A cohort of 50 patients was identified, with mean ± SD age 59.6 ± 13.9 years and 86% women. Serum calcium in the cohort was 11.1 ± 1.1 mg/dL, phosphate was 3.3 ± 0.6 mg/dL, and PTH was 76 ± 42 pg/mL. Serum 25-hydroxyvitamin D was 25 ± 9 ng/mL, and serum 1,25-dihydroxyvitamin D was 51 ± 20 pg/mL; 24-hour urine calcium was 275 ± 211 mg. In subjects with sarcoidosis, serum angiotensin-converting enzyme (ACE) was 47.2 ± 37.4 U/L. Sarcoidosis was diagnosed first in 50% of patients, PHPT was diagnosed first in 16% of patients, and sarcoidosis and PHPT were both diagnosed within 6 months of each other in 30% of patients. The interval between the 2 diagnoses when sarcoidosis was diagnosed first was 15.5 ± 12.4 years and was 5.5 ± 6.0 years when PHPT was diagnosed first. Patients with PHPT who had active sarcoidosis had higher serum ACE levels (60.9 ± 38.1 vs 20.2 ± 14.0 U/L, P <.0001), lower PTH levels (60 ± 24 vs 96 ± 41 pg/mL, P = .01), and lower phosphate levels (2.7 ± 0.6 vs 3.2 ± 0.5 mg/dL, P = .02). CONCLUSIONS: Fifty patients with coexisting PHPT and sarcoidosis are described, with patients with PHPT coexisting with clinically active sarcoidosis having increased serum ACE levels and decreased serum PTH and phosphate levels compared with those with inactive sarcoidosis.

[The importance of hypercalciuria in assessing the clinical course and treatment modalities of sarcoidosis].

INTRODUCTION: In patients with sarcoidosis high levels of Ca2+ in blood serum accompanied by increased 24-hour urinary calcium are of great diagnostic and prognostic value. High levels of these two important parameters may point to hyperparathyroidism and/or chronic sarcoidosis. It is necessary to exclude kidney insufficiency by kidney ultrasound. MATERIAL AND METHODS: During the previous four years (1999-2003), urinary Ca was significantly higher than the physiological level in 25 patients, whereas the blood serun Ca was normal. 18 patients received corticosteroid therapy (40 mg for two months, and 35 mg later on). Patients with acute sarcoidosis received prednisone for 11.8 months, while patients with chronic sarcoidosis received it for 13.6 months. One patient with chronic sarcoidosis received methotrexate, as alternative therapy. RESULTS: 4 months later, after normalization of urinary Ca excretion, the follow-up of patients revealed only one patient with increased urinary Ca excretion associated with increased ACE and radiographic progression of the disease.

Pregnancy and sarcoidosis: an insight into the pathogenesis of hypercalciuria.

Hypercalciuria with or without hypercalcemia is a well-known complication of sarcoidosis, the pathogenesis of which is not fully understood. Pregnancy is associated with physiologic alterations in calcium metabolism. These changes can further alter the derangement of calcium metabolism that occurs in sarcoidosis, if the two conditions coexist. We had the opportunity to study prospectively the changes in serum and urine calcium along with all the hormonal changes that occur during pregnancy in a young woman with sarcoidosis, who had hypercalciuria at presentation. We believe that an increased level of calcitriol is central to the calcium abnormalities in our patient. In her case, the increased calcitriol is derived from sarcoid granulomas and renal sources enhanced by the effect of estradiol and prolactin on the conversion of 25(OH)D to 1,25(OH)(2) D. She acquired hypoparathyroidism, with normal serum calcium, which probably was due to the direct suppression of parathyroid hormone (PTH) secretion by calcitriol. Finally, hypercalciuria is the result of the combined effect of hyperabsorption of calcium from the gut (the result of increased calcitriol levels leading to increased filtration of calcium) and decreased tubular reabsorption of calcium, as a result of undetectable PTH.

Sarcoidosis associated with acute renal failure and increased levels of interleukin-6 in urine.

A 24-year-old man who had uveitis and showed intrathoracic lymph node swelling on a chest X-ray, was admitted to our hospital for further examination. Transbronchial lung biopsy specimens revealed non-caseating granulomas compatible to sarcoidosis. As the renal function became progressively worse, a specimen was obtained by renal biopsy. It showed a granuloma formation, and was diagnosed as renal sarcoidosis. A high level of interleukin (IL)-6 was detected in his urine. After oral administration of prednisolone, the renal function improved, and the urinary IL-6 level was reduced. These findings suggest that in sarcoidosis associated with renal failure, steroid therapy is effective and that IL-6 plays an important role in the pathogenesis of renal involvement of sarcoidosis.

[Biological tests in sarcoidosis: contribution to diagnosis and surveillance]. / Examens biologiques dans la sarcoïdose: apport au diagnostic et à la surveillance.

No single laboratory examination is diagnostic. On the other hand, such examinations support the diagnosis and aid in management of treated patients. In the serum, there is lymphopenia with a lowered CD4/CD8 ratio. An increase in beta 2-microglobulin and in the soluble IL-2 receptor reflect T lymphocyte activation. A classic observation is hypercalcaemia with hypercalciuria. The increase in angiotensin I converting enzyme reflects the body granulomatous mass. The results of bronchoalveolar lavage show the characteristics of the alveolitis associated with granulomatosis, accumulation of CD4+ T lymphocytes and activated alveolar macrophages. In practice, biochemical anomalies are of interest in the follow-up of treated patients.

Urinary excretion of protein and non-protein hydroxyproline in patients with sarcoidosis and interstitial pulmonary fibrosis.

The determination of total hydroxyproline (Hyp) with separation into protein and non-protein fractions was carried out in 24-hour urine samples of healthy persons, patients with sarcoidosis and patients with interstitial pulmonary fibrosis (i.p.f.). In the group of sarcoidosis Hyp excretion was evaluated taking into account progression of pulmonary changes and disease activity. It was found that total and non-protein Hyp excretion correlated positively in healthy persons as well as in those with sarcoidosis, and interstitial pulmonary fibrosis. An increased excretion of total and non-protein Hyp occurred in 24% of the patients with sarcoidosis while excretion of protein Hyp remained within the normal range. In 30% of the patients with interstitial pulmonary fibrosis increased excretion of total and non-protein Hyp was demonstrated. The excretion of protein Hyp in these patients did not deviate from normal values. The results of our study indicate that determination of total and nonprotein Hyp in urine may be useful in the evaluation of fibrotic changes in the pulmonary diseases mentioned above. However, these parameters are not usefull in differentiation between sarcoidosis and interstitial pulmonary fibrosis.

Urinary neopterin in pulmonary sarcoidosis. Relationship to clinical and biologic assessment of the disease.

Neopterin is a metabolite of guanosine-triphosphate, released in vitro by macrophages under the control of gamma-interferon and described as a marker of T cell activation in vivo. We have compared the urinary neopterin/creatinine ratio (mumol/mol) in patients with pulmonary sarcoidosis (n = 66), interstitial lung diseases other than sarcoidosis (nonsarcoid ILD, n = 35), and 45 normal control subjects. For the sarcoid population as a whole, urinary neopterin was higher (496 +/- 52 mumol/mol [mean +/- SEM]) than in control subjects (126 +/- 5 mumol/mol) (p less than 0.001). In patients with nonsarcoid ILD, urinary neopterin was frequently higher in granulomatous and/or lymphoproliferative diseases (hypersensitivity pneumonitis, tuberculosis, primitive Sjögren's syndrome, and malignant lymphomas) (781 +/- 193 mumol/mol, n = 10) but remained normal in other types of nonsarcoid ILD [( 163 +/- 14 mumol/mol, n = 25]: histiocytosis X, idiopathic pulmonary fibrosis, lung collagen-vascular diseases, diffuse neoplasms, pneumoconiosis; p less than 0.001 compared with sarcoidosis). We have also evaluated the relationship between urinary neopterin and the clinical or biologic markers currently used to assess sarcoidosis: alveolar lymphocytosis in lavage fluid (ALY), 67-gallium scan semiquantitative index (67Ga), or serum angiotensin-converting enzyme (SACE). Sarcoid patients with the highest urinary neopterin were those in whom mean values of these markers were the highest (p less than 0.05, all comparisons). Patients with positive markers (i.e., either clinical expression of sarcoidosis-ALY greater than 30%-67Ga greater than 20-SACE greater than 60 U/ml) had significantly higher urinary neopterin levels than did other sarcoid patients (p less than 0.05, all comparisons).

Urinary neopterin excretion in pulmonary sarcoidosis: correlation to clinical course of the disease.

Urinary neopterin levels were determined by high pressure liquid chromatography in 36 patients with pulmonary sarcoidosis. Values were above normal range in 69.4% of all patients. Neopterin excretion was significantly higher in radiologic types II/III than in type I disease (p = 0.0265, Mann-Whitney U-test). Urinary neopterin showed a weak, but significant inverse correlation to disease duration (r = -0.36; p = 0.034, Spearman's rank correlation). No significant correlation could be found between neopterin and the presence of pulmonary or extrapulmonary symptoms, vital capacity, forced expiratory volume in the first second, steroid treatment, and serum angiotensin converting enzyme. Follow-up studies revealed that worsening or improvement of chest X-ray findings was invariably accompanied by rising or decreasing neopterin excretion, respectively. Patients with normal neopterin at initial evaluation had a higher tendency towards spontaneous healing, and none of them deteriorated during the follow-up period. We conclude that urinary neopterin excretion reflects one aspect of alveolitic "activity" in pulmonary sarcoidosis and that normal values probably indicate a favorable prognosis.

Enhanced production rate of 1,25-dihydroxyvitamin D in sarcoidosis.

We determined the metabolic clearance and production rates of 1,25-dihydroxyvitamin D [1,25-(OH)2D] in 5 patients with sarcoidosis who had either hypercalciuria or hypercalcemia to examine whether abnormalities in the metabolism of this hormone existed. The mean MCR in the 5 patients with sarcoidosis [40 +/- 9 (+/- SD) mL/min] was similar to that in 13 normal subjects (37 +/- 6 mL/min) and that in 9 patients with absorptive hypercalciuria and renal stones (35 +/- 4 mL/min). However, the mean serum 1,25-(OH)2D concentration was significantly higher in the patients with sarcoidosis (211 +/- 60 pmol/L) than in either of the other 2 groups. The mean 1,25-(OH)2D production rate was markedly elevated in the patients with sarcoidosis (12.4 +/- 5.3 mumol/day), being more than 2-fold greater than the normal mean value (5.4 +/- 1.2 mumol/day). The highest production rates were found in patients with hypercalcemia, whereas subjects with hypercalciuria had production rates comparable to those in the patients with absorptive hypercalciuria. These data indicate that there is no impairment in the clearance of 1,25-(OH)2D in patients with sarcoidosis and that the elevated serum 1,25-(OH)2D levels are due to an increase in its production rate.

Hypercalciuria and renal stones in a sarcoidosis patient treated by extracorporeal shockwave lithotripsy.

A case of chronic pulmonary sarcoidosis and hypercalciuria complicated by bilateral renal stones is reported. Urinary stones were pulverized by extracorporeal shockwave lithotripsy (ESWL) as the patient had declined any surgical procedure. The use of ESWL in conjunction with corticosteroids appears to be the treatment of choice in the management of renal stones secondary to abnormalities of calcium metabolism in sarcoidosis.

Urinary cyclic AMP corrected for glomerular filtration rate in the differential diagnosis of hypercalcemia.

To evaluate the usefulness of urinary cyclic AMP (U-cAMP) expressed as nmol/100 ml glomerulus filtrate (GF) when discriminating various hypercalcemic states, we studied 99 patients. Patients with primary hyperparathyroidism (PHPT) showed a positive correlation between individual S-calcium levels and U-cAMP, nmol/100 ml GF (females r=0.49, n=40, p less than 0.01 and males r=0.91, n=7 p less than 0.001). There was also a correlation between U-cAMP, nmol/100 ml GF, and the weight of the adenomas (females r=0.36, n=32, p less than 0.05) and males r=0.79, n=6, p less than 0.05). Patients with PHPT and normal renal function excreted more U-cAMP than controls, 6.0 +/- 1.6 versus 4.3 +/- 1.0 nmol/100 ml GF (mean +/- SD). Of 47 patients with PHPT and normal renal function, 29 showed values below the upper normal limit, 6.3 nmol/100 ml GF (mean +/-2 SD), of the control group; the overlap was 62%. When U-cAMP was expressed as mumol/24 hours, the overlap was 40/47 (85%) and, when expressed as mumol/g creatinine, 31/47 (66%). Three patients with sarcoidosis and two with malignancies and hypercalcemia showed excretory values of U-cAMP, nmol/100 ml GF, above the upper normal limit. Patients with acromegaly or prolactinoma showed normal values of U-cAMP, nmol/100 ml GF. The present data indicate that all three types of determinations of urinary cAMP based on 24 hour urine collections are of little value in the differential diagnosis of hypercalcemic states.