Characteristics of the patients
Individuals with sarcoidosis and controls were well matched according to demographic factors, including age, gender, BMI, smoking status, and prevalence of comorbidities (Table 1). at table two we have provided features of the manifestation of sarcoidosis. As shown, the median disease duration was six (range 3-9) years, and the median age at diagnosis was 42 (range 35-50) years. In 11 (21%) patients, sarcoidosis was diagnosed incidentally at an asymptomatic stage due to abnormal chest radiographs obtained as a screening test for prophylactic purposes. The remaining subjects had constitutional signs, such as fatigue or weakness (n = 38, 71.7%), reduced exercise tolerance (n = 34; 64.2%), and pulmonary symptoms, such as cough and dyspnea (n = 41, 77 ,4 %). All patients had pulmonary sarcoidosis, with radiological stage 2 in most cases (n = 42, 79.2%), that is, hilar or mediastinal lymph node enlargement and parenchymal changes. The most common extrapulmonary manifestations are skin changes (n = 12, 37.7%), extrathoracic lymphadenopathy (n = 11, 20.8%), and splenomegaly (n = 7, 13.2%). The other rare manifestations included liver damage, nasal septal perforation, optic nerve involvement, and uveitis. two). Interestingly, in 2 cases (3.8%), sarcoidosis occurred in close relatives in the past.
Almost half of the patients were treated with systemic corticosteroids for a median duration of 3 years (interquartile range 3-8 years), while only n = 9 (17%) received oral corticosteroids at the time of evaluation (Table two). Two subjects (3.8%) were currently or in the past treated with methotrexate. No other immunosuppressants were used in our patients.
In addition, due to arterial hypertension, patients with sarcoidosis were frequently treated with angiotensin-converting enzyme inhibitors or angiotensin receptor antagonists (n = 12; 37.7%), beta-blockers (n = 10; 18, 9%) and diuretics (n = 7; 13.2%). Three (5.7%) of them applied non-steroidal anti-inflammatory drugs or aspirin.
Results of lung function tests in patients with sarcoidosis are also provided in Table two; most individuals had them within the normal range.
Transthoracic echocardiographic parameters (Table 3)
Transthoracic echocardiographic measurements revealed that patients with sarcoidosis had larger right ventricular dimensions, thicker interventricular septum, and posterior LV walls (Table 3). They also had a slightly lower LV ejection fraction than controls. Interestingly, the two study groups also differed in diastolic cardiac function parameters. For example, in sarcoidosis, we have documented a prolonged isovolumic relaxation time in the left and right ventricle, a longer E wave deceleration time (of the mitral and tricuspid valve, respectively), and an increased E/R ratio. A and E/e’ along the ventricle. the mitral valve. In addition, we found several indices in the patient group that suggested a higher probability of pulmonary hypertension, such as increased systolic and mean pulmonary artery pressure, elevated tricuspid regurgitation velocity, and decreased pulmonary velocity acceleration time. . In addition, the left atrial volume index was higher in sarcoidosis than in controls (Table 3).
Routine blood laboratory tests and biomarkers of endothelial damage (Table 1)
Despite clinical remission, sarcoidosis was characterized by significantly higher concentrations of inflammatory markers, such as CRP, IL-6, and fibrinogen. These patients also had slightly elevated D-dimer, FVIII:C, red blood cells, and platelets, lower lymphocyte counts, elevated triglycerides, and high-density lipoprotein cholesterol (Table 1). Furthermore, although the entire sarcoidosis group showed only a trend toward higher concentrations of biomarkers of serum endothelial damage, including thrombomodulin and VCAM-1.p= 0.09, both), patients with the coexisting extrapulmonary manifestation, eg, extrathoracic lymphadenopathy, had elevated circulating VCAM-1 compared with the remaining subjects (1295.7 [95% CI 954.9—1636.6] ng/ml, n = 11 vs 882.1 [95% CI 835.3–928.8] ng/mL, n=42; p<0.001). In addition, those with documented prolonged hypercalcemia were characterized by increased peripheral blood thrombomodulin (6305 [95% CI 5175–7436] ng/ml, n = 11, vs 4997 [95% CI 4668–5327] ng/mL, n=42; p= 0.002).
Thrombomodulin and VCAM-1 concentrations correlated well with each other (r = 0.83, p= 0.003), and both were related to plasma D-dimer (r = 0.85, p= 0.003 and r = 0.91, p< 0.001, respectively).
As expected, PCR was associated with IL-6 (r = 0.77, p< 0.001), which also remained in a positive relationship with plasma thrombomodulin (r = 0.78, p= 0.008). In addition, CRP and IL-6 were associated with D-dimer (r = 0.75, p= 0.012 and r = 0.69, p= 0.026, respectively).
thrombin generation assay
In the thrombin generation assay, patients with sarcoidosis had an unfavorably altered thrombin generation profile, characterized by 16% higher ETP, 24% higher peak TG (p< 0.001 both, also after adjusting for possible confounding) and a 12% faster ttPeak (p= 0.004 after adjustment for possible confounding) compared to controls (Fig. two.).
In sarcoidosis, we have documented higher odds of having elevated ETP and peak TG, given the following cut-off points: elevated ETP OR 2.92 [95% CI 1.9–4.51]for a cutoff of 1737 nmol/l × min, p< 0.001, maximum elevation of TG OR 5.73 [95% CI 3.2–10.25] for a cutoff of 352.7 nmol/l, p<0.001.
Consequently, a predictive logistic regression model based on D-dimer, ETP, and ttPeak was able to discriminate between sarcoidosis patients and the control group with ROC AUC of 0.851 (AUC error of 0.0431) and cut-off points of 275 ng/mL. , 1737 nmol/L × min and 5.38 min for D-dimer, ETP and ttPeak, respectively (p< 0.0001 for that model).
Thrombin generation parameters were independent of demographic factors, including gender, age, and BMI in both study groups. In turn, among the basic laboratory measurements, only triglycerides were related to CAT assay variables, such as ETP and peak TG (r = 0.42, p= 0.03 and r = 0.52, p= 0.03, respectively).
Subgroup analysis revealed that neither radiological stage of the disease, symptoms at diagnosis, past inhaled corticosteroids, nor use of immunosuppressants were related to the altered thrombin generation profile. In turn, PTE was higher in those with extrapulmonary-extracutaneous manifestations, including involvement of the optic nerve, uvea, nasal septum, and/or liver (1986 [1887–2027] nmol/L × min, n = 6 vs 1753 [1472–1921] nmol/L × min, n=47; p= 0.02). The number of affected organs did not correlate with the thrombin generation parameters.
Furthermore, patients on systemic corticosteroids, currently or in the past, were characterized by increased thrombin formation in the CAT assay. Patients treated in the past had higher PTE compared with never-treated patients (1872 [95% CI 1721–2022] nmol/L × min, n = 25 vs 1670 [95% CI 1577–1764] nmol/L × min, n=28; p= 0.02), while patients using corticosteroids at evaluation had an elevated peak TG compared with those currently not receiving treatment (420.7 [95% CI 354.9–486.5] nmol/L, n = 9 vs 367.9 [95% CI 350.7–385.1] nmol/L, n=44; p= 0.023).
Interestingly, in sarcoidosis, ETP was inversely correlated with total lung capacity (TLC, r = -0.46, p= 0.03) and vital capacity (VC) before the bronchodilator (r = -0.32, p= 0.04). Consequently, PTE was significantly higher in the only four patients (7.5%) with TLC below the normal range, compared with the remaining individuals with sarcoidosis (2136 [95% CI 1283–2988] nmol/L × min vs. 1706 [95% CI 1557–1854] nmol/L × min, p= 0.04).
A multiple regression model (Table 4) showed that blood platelet count and serum IL-6 were independently and positively associated with ETP. Likewise, platelet count and FVIII:C remained positively related to peak TG. In addition, both thrombin generation variables analyzed were independently related to the concentration of thrombin-antithrombin complexes (positively) and eGFR (negatively). However, these variables explained only 32% and 43% of the variability of peak ETP and TG.
Regarding echocardiographic measurements, we found a positive association between PTE and systolic pulmonary arterial pressure (β = 0.26 [95% CI 0.12–0.4], p= 0.04, after adjusting for possible confounding factors).
