Sarcoidosis: historical perspective and immunopathogenesis (Part I)

Clinical Pharmacology in Sarcoidosis: How to Use and Monitor Sarcoidosis Medications

When sarcoidosis needs treatment, pharmacotherapy is usually required. Although glucocorticoids work reliably and relatively quickly for sarcoidosis, these drugs are associated with numerous significant side effects. Such side effects are common in sarcoidosis patients, as the disease frequently has a chronic course and glucocorticoid treatment courses are often prolonged. For these reasons, corticosteroid-sparing and corticosteroid-replacing therapies are often required for sarcoidosis. Unfortunately, many healthcare providers who care for sarcoidosis patients are not familiar with the use of these agents. In this manuscript, we provide a review of the pharmacotherapy of sarcoidosis. We discuss the mechanism of action, dosing, side-effect profile, approach to monitoring and patient counselling concerning glucocorticoids, and the common alternative drugs recommended for use in the recent European Respiratory Society (Lausanne, Switzerland) Sarcoidosis Treatment Guidelines. We also discuss the use of these agents in special situations including hepatic insufficiency, renal insufficiency, pregnancy, breastfeeding, vaccination, and drug-drug interactions. It is hoped that this manuscript will provide valuable practical guidance to clinicians who care for sarcoidosis patients.

Sarcoidosis presenting as bilateral optic neuritis after ChAdOx1 nCoV-19 vaccination

Sarcoidosis is an idiopathic granulomatous disease and can virtually affect any organ system. Multiple factors, including tubercular antigens organic and environmental exposures, have been implicated in its pathogenesis. In addition to drugs, sarcoid-like reactions have been reported following varicella and influenza vaccination. Few reports of erythema nodosum and Lofgren syndrome have been reported after the COVID19 vaccination, though no histologic diagnosis was pursued in these cases. We herein report a case of sarcoidosis presenting with bilateral acute onset vision loss with a temporal association with COVID19 vaccination (ChadOx-1 n-COV, COVISHIELDTM). Symptoms started within two weeks of receiving the vaccine. Alternate causes for optic neuritis were excluded. Transbronchial lung biopsy showed the presence of non-caseating epithelioid cell granulomas. The patient received high-dose corticosteroids immediately after diagnosis, albeit with incomplete clinical improvement in vision on a three-month follow-up. In conclusion, we report a novel case of sarcoidosis-related optic neuritis following COVID19 vaccination.

A Primer on the Clinical Aspects of Sarcoidosis for the Basic and Translational Scientist

The immunopathogenesis of sarcoidosis remains unclear. This failure in understanding has been clinically impactful, as it has impeded the accurate diagnosis, treatment, and prevention of this disease. Unraveling the mechanisms of sarcoidosis will require input from basic and translational scientists. In order to reach this goal, scientists must have a firm grasp of the clinical aspects of the disease, including its diagnostic criteria, the immunologic defects, clinical presentations, response to therapy, risk factors, and clinical course. This manuscript will provide an overview of the clinical aspects of sarcoidosis that are particularly relevant for the basic and translational scientist. The variable phenotypic expression of the disease will be described, which may be integral in identifying immunologic disease mechanisms that may be relevant to subgroups of sarcoidosis patients. Data concerning treatment and risk factors may yield important insights concerning germane immunologic pathways involved in the development of disease. It is hoped that this manuscript will stimulate communication between scientists and clinicians that will eventually lead to improved care of sarcoidosis patients.

The value of endobronchial ultrasound-guided transbronchial needle aspiration, 18-fluorodeoxyglucose positron emission tomography/computed tomography, and ultrasonography imaging techniques in the diagnosis of mediastinal and/or hilar malignant, anthracotic, and other benign lymph nodes

INTRODUCTION

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a simple, reliable, minimally invasive and effective procedure. However, a surgical technique may be required, if the results are negative. Therefore, there is a need for new studies to increase the diagnostic value of EBUS-TBNA and provide additional information to guide the biopsy in performing the procedure. Here, we aimed to investigate the diagnostic value of EBUS-TBNA and 18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in diagnosis of hilar and/or mediastinal lymph nodes (LNs). It was also aimed to determine the contributions of real-time ultrasonography (USG) images of LNs to distinguishing between the malignant and benign LNs during EBUS-TBNA, and in the diagnosis of anthracotic LNs.

MATERIAL AND METHOD

In the retrospective study including 545 patients, 1068 LNs were sampled by EBUS-TBNA between January 2015 and February 2020. EBUS-TBNA, 18-FDG PET/CT and images of USG were investigated in the diagnosis of mediastinal and/or hilar malignant, anthracotic and other benign LNs.

RESULTS

The sensitivity, specificity, positive predictive value and negative predictive value of EBUS-TBNA were found as 79.5, 98.1, 89.5, and 91.7%, respectively. Mean maximum standardized uptake value (SUVmax) values of 18F-FDG PET/CT were 6.31±4.3 in anthracotic LNs and 5.07 ± 2.53 in reactive LNs. Also, mean SUVmax of malignant LNs was 11.02 ± 7.30 and significantly higher than that of benign LNs. In differentiation of malignant-benign tumors, considering the cut off value of 18F-FDG PET/CT SUVmax as 2.72, the sensitivity and specificity was 99.3 and 11.7%, but given the cut off value as 6.48, the sensitivity, specificity, positive predictive value and negative predictive value was found as 76.5, 64, 20.49, and 78.38% for benign LNs, respectively. Compared LNs as to internal structure and contour features, malignant LNs had most often irregular contours and heterogeneous density. Anthracotic, reactive and other benign LNs were most frequently observed as regular contours and homogeneous density. The difference between malignant and benign LNs was significant.

CONCLUSION

EBUS can contribute to the differential diagnosis of malignant, anthracotic and other benign LNs. Such contributions can guide clinician bronchoscopists during EBUS-TBNA. The triple modality of EBUS-TBNA, 18FDG PET/CT, and USG may increase the diagnostic value in hilar and mediastinal lymphadenopathies.

The Association of Neutrophil/Lymphocyte and Platelet/Lymphocyte Ratios and Hematological Parameters with Diagnosis, Stages, Extrapulmonary Involvement, Pulmonary Hypertension, Response to Treatment, and Prognosis in Patients with Sarcoidosis

Sarcoidosis is a rare disease characterized by granulomatous inflammation in affected organs, primarily in lungs. Neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR) are easy and practical methods providing valuable information in diagnosis, severity, and prognosis of various diseases. Here, we aimed to investigate the association between NLR, PLR, and hematological parameters in sarcoidosis. The study was performed with 75 sarcoidosis patients and 92 controls. Patients' NLR, PLR, and hematological parameters were compared with those of controls. Additionally, while differences between NLR and PLR were investigated in sarcoidosis patients, differences of extrapulmonary involvement, pulmonary hypertension (PH), and spontaneous remission between those with and without responses to treatment concerning stages were also assessed. NLR and PLR were significantly higher in sarcoidosis patients than controls. For NLR, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were found as 68, 61, 58, and 70% respectively, while sensitivity, specificity, PPV, and NPV for PLR were found as 72, 67, 63, and 74%, respectively. In sarcoidosis patients, NLR and PLR were significantly higher at stage-2 and -3 than at stage -1 and -4. There was a significant weak positive correlation between C-reactive protein (CRP) and NLR and PLR. Mean platelet volume (MPV), hemoglobin (Hgb), and mean corpuscular volume (MCV) were lower among patients than controls. A positive moderate correlation was detected between NLR and CD4/CD8 in blood, while there was a strong positive correlation between CD4/CD8 in bronchoalveolar lavage (BAL) and positive moderate correlation between PLR and CD4/CD8 in BAL. High NLR and PLR values were not significantly associated with pulmonary PH, spontaneous remission, response to treatment, and prognosis. The increase in PLR and NLR may be a guide for diagnoses of both sarcoidosis and lung parenchymal involvement. To use these entities as markers, our findings should be supported with prospective studies with larger samples.

The potential additional benefit of infliximab in patients with chronic pulmonary sarcoidosis already receiving corticosteroids: a retrospective analysis from a randomized clinical trial

BACKGROUND

Infliximab, a TNF-alpha antagonist, has shown efficacy in the treatment of sarcoidosis. Since corticosteroids inhibit TNF-alpha expression, we postulated that sarcoidosis patients receiving a sufficient corticosteroid dose may have an attenuated response to the addition of infliximab.

METHODS

We analyzed data from a previous randomized double blind prospective trial of infliximab versus placebo for chronic pulmonary sarcoidosis. The effect of the maintenance corticosteroid dose on the change in FVC % predicted between 0 and 24 weeks (ΔFVC%pred0-24) was analyzed in two ways. First, the mean ΔFVC%pred0-24 was calculated for the placebo and infliximab groups using three different daily prednisone equivalent dose thresholds: a) <10 mg versus ≥10 mg; b) <15 mg versus ≥15 mg; c) <20 mg versus ≥20 mg. Second, in both the placebo and infliximab groups, a correlation coefficient was calculated between the maintenance corticosteroid dose and ΔFVC%pred0-24.

RESULTS

Both the group that received infliximab and either a maintenance daily dose of <10 mg of prednisone and the group receiving ≥10 mg had a significant increase in FVC%pred0-24. However, both the groups that received infliximab and a corticosteroid dose of >15 mg of prednisone and ≥20 mg of prednisone did not demonstrate a significant ΔFVC%pred0-24. For the placebo group, there was no significant correlation between the corticosteroid dose and the ΔFVC%pred0-24. For the infliximab group, there was a significant correlation (p = 0.0097) between higher corticosteroid dose and less improvement in FVC%pred0-24.

CONCLUSION

Our results suggest that infliximab adds minimal potential benefit to corticosteroids for pulmonary sarcoidosis at doses above 15-20 mg/day of prednisone.

Current and emerging pharmacological treatments for sarcoidosis: a review

The treatment of sarcoidosis is not standardized. Because sarcoidosis may never cause significant symptoms or organ dysfunction, treatment is not mandatory. When treatment is indicated, oral corticosteroids are usually recommended because they are highly likely to be effective in a relative short period of time. However, because sarcoidosis is often a chronic condition, long-term treatment with corticosteroids may cause significant toxicity. Therefore, corticosteroid sparing agents are often indicated in patients requiring chronic therapy. This review outlines the indications for treatment, corticosteroid treatment, and corticosteroid sparing treatments for sarcoidosis.

A case series of refractory cutaneous sarcoidosis successfully treated with infliximab

INTRODUCTION

Sarcoidosis is a systemic granulomatous disease of unknown cause. The management of sarcoidosis remains problematic. Systemic and topical corticosteroids are the mainstay of therapy but may cause unacceptable side effects. Biologic therapies, such as infliximab, have recently been proposed as another treatment option for cutaneous sarcoidosis.

CASE REPORT

The authors describe three patients who were diagnosed with cutaneous sarcoidosis with systemic involvement. All of the patients were refractory to conventional therapies but responded to infliximab therapy.

CONCLUSION

Infliximab is an alternative medication for refractory sarcoidosis that has a relatively benign side-effect profile. However, definite indications, dosage, interval, and duration of treatment for cutaneous sarcoidosis are not firmly established.

Allergic bronchopulmonary aspergillosis after infliximab therapy for sarcoidosis: a potential mechanism related to T-helper cytokine balance

We report a case of allergic bronchopulmonary aspergillosis (ABPA) that occurred in a man receiving infliximab for systemic sarcoidosis. His symptoms associated with ABPA were temporally related to his infliximab infusions. We suspect that infliximab disrupted the T-helper (Th) type 1-Th2 lymphocyte balance such that Th2 cytokines were left relatively unopposed, promoting the development of ABPA.

BAL fluid cells in newly diagnosed pulmonary sarcoidosis with different clinical activity

BACKGROUND

Sarcoidosis is associated with an increase in the number of alveolar T cells (CD3(+) cells) and an increase of the CD3(+)CD4(+) lymphocyte subset. However, the number of lymphocytes and the CD4/CD8 ratio in bronchoalveolar lavage (BAL) fluid are highly variable in sarcoidosis. Comparative studies have demonstrated that geographic and ethnic factors are linked to the specific characteristics of patients with sarcoidosis.

AIM OF THE STUDY

To investigate peculiarities of BAL fluid (BALF) cell patterns in different clinical activity of pulmonary sarcoidosis at the time of diagnosis.

MATERIAL AND METHODS

A total of 308 non-treated patients (138 asymptomatic and 170 with sarcoidosis-related symptoms) and 40 previously empirically steroid-treated patients with newly diagnosed sarcoidosis have been prospectively examined.

RESULTS

Significant BAL fluid lymphocytosis and increased CD4/CD8 ratio were characteristic for all three sarcoidosis patient groups. A total of 12% of asymptomatic patients, 3% of patients with sarcoidosis-related symptoms, and 5% of previously treated symptomatic patients had normal BALF cell counts. Non-treated patients with sarcoidosis-related symptoms had significantly higher lymphocytosis (45+/-19% versus 39+/-17%, P<0.01), CD4/CD8 ratio (9.3+/-5.0 versus 5.7+/-4.5, P<0.001), and total BALF cell count (411+/-322 10(6)/mL versus 334+/-273 10(6)/mL, P<0.05), compared with asymptomatic patients. However, previously treated symptomatic patients had lower lymphocytosis (39+/-15% versus 45+/-19%, P=0.058), and total BALF cell count (292+/-166 10(6)/mL versus 411+/-322 10(6)/mL, P<0.05) compared with non-treated symptomatic patients. The same trend was noticed for CD4/CD8 ratio (8.3+/-4.8), although a statistically significant difference was not achieved.

CONCLUSIONS

Independently of clinical symptoms at the time of diagnosis sarcoid patients have significantly different BAL fluid cell patterns compared to healthy persons. BAL fluid cell changes are more prominent in corticosteroid non-treated patients with clinically active sarcoidosis. Treatment with systemic corticosteroids may modify typical BALF cellular patterns of sarcoidosis.

Ultrastructural types of alveolar macrophages in bronchoalveolar lavages from patients with pulmonary sarcoidosis

By routine applied quantitative BAL methods are particularly helpful for the diagnosis of pulmonary sarcoidosis. Here the morphology of the alveolar cells does not play a role. However, morphological and especially electron microscopic investigations might contribute to the clarification of the aetiology of this disease. In a prospective study we investigated the bronchoalveolar lavages (BALs) from 10 patients with recently histologically diagnosed, untreated pulmonary sarcoidosis. Commonly applied cytological and immunological BAL diagnostic techniques were accompanied by morphological investigations of alveolar cells, especially alveolar macrophages, using light and electron microscopy. All patients showed lymphocytic alveolitis with an increased number of CD4 positive lymphocytes as well as an increased CD4/CD8 ratio. A striking light microscopic finding was the great morphological variety of the alveolar macrophages. Electron microscopy revealed typical lymphocytes, neutrophils, and eosinophils as well as three different types of alveolar macrophages in all 10 patients: type I (approx. 30%) with a normal macrophage morphology, a vacuole-rich type II (approx. 30%) with myelin-like structures and type III (approx. 40%) with electron-dense inclusions. The occurrence of intracellular myelin figures in type II macrophages is a hint for increased phagocytotic processes of surfactant with or without its overproduction in the sense of a secondary alveolar proteinosis. Numerous electron-dense inclusions in type III also indicate an increased macrophage activity that leads to an increased release of cytokines, which in turn can trigger an inflammatory reaction.

Role of bronchoalveolar lavage in interstitial lung disease

Bronchoalveolar lavage remains an important research tool in understanding ILD. It is still an important part of the clinical management of patients with ILD. It is most useful in detecting unusual forms of ILD. It helps the clinician narrow down the possible causes of the interstitial pattern. It also can confirm a clinical impression of certain conditions. Although rarely diagnostic, it is often supportive. In conjunction with high-resolution CT scan, most patients with ILD can be diagnosed using relatively noninvasive methods.

Role of IL-18 in CD4+ T lymphocyte activation in sarcoidosis

Sarcoidosis is a granulomatous disease of unknown etiology associated with the expansion of IL-2-producing activated CD4(+) T lymphocytes. A number of factors including the recently described IL-18 have been implicated in IL-2 expression in vitro. We investigated the role of IL-18 in IL-2 expression in sarcoidosis. Eighteen individuals with sarcoidosis and 15 normal controls were studied. IL-18R expression and epithelial lining fluid (ELF) concentrations of IL-18 were significantly elevated in the sarcoid group (p = 0.0143 and 0.0024, respectively). Both AP1 and NF-kappaB, transcription factors that regulate IL-2 gene expression, were activated in vivo in sarcoid pulmonary CD4(+) T lymphocytes. Transcription factor activity was not detected in pulmonary CD4(+) T lymphocytes from normal controls or from peripheral blood CD4(+) T lymphocytes from individuals with sarcoidosis, further evidence of compartmentalization of the lymphoproliferative process in this condition. We examined the effects of IL-18 on AP1 and NF-kappaB in Jurkat T cells in vitro. These effects were both time and dose dependent. Examination of transcription factor activation and IL-2 gene expression in Jurkat T cells revealed that sarcoid but not normal ELF activated AP1 and NF-kappaB, induced IL-2 gene transcription, and up-regulated IL-2 protein production. Addition of IL-18 to normal ELF also induced IL-2 mRNA accumulation, whereas correspondent depletion of IL-18 from sarcoid ELF using neutralizing Abs abrogated all of the effects. These data strongly implicate IL-18 in the pathogenesis of sarcoidosis via activation of AP1 and NF-kappaB, leading to enhanced IL-2 gene expression and IL-2 protein production and concomitant T cell activation.

Serum level of soluble tumour necrosis factor receptor II (75 kDa) indicates inflammatory activity of sarcoidosis

OBJECTIVES

Tumour necrosis factor alpha (TNFalpha) is a key cytokine involved in granuloma formation of sarcoidosis. Since soluble TNF receptors (sTNF-R) are known to inhibit TNF effects, we were interested in whether they are elevated in the serum of sarcoidosis patients.

METHODS

We determined serum levels of sTNF-R I (55 kDa) and sTNF-R II (75 kDa) in 49 patients with sarcoidosis and 22 controls. The clinical course of the disease was re-evaluated in a follow-up after (mean +/- SE) 6.8 +/- 6.6 months.

RESULTS

sTNF-R I (3.1 +/- 1.1 ng mL-1, P < 0.05) and sTNF-R II (5.5 +/- 2.7 ng mL-1, P < 0.0005) were significantly elevated in sarcoidosis compared with controls (2.4 +/- 0.7 and 3.0 +/- 1.3 ng mL-1, respectively). Interestingly, both sTNF receptors were significantly higher in the serum of patients with active compared with inactive sarcoidosis (P < 0.005 and P < 0.0005, respectively). Furthermore, serum sTNF-R II levels were significantly higher in sarcoidosis patients with advanced radiological types II and III. In 10 patients, serum sTNF-R levels were obtained before and after systemic corticosteroid therapy and we observed a significant decrease of sTNF-R II (P < 0.02), whereas sTNF-R I levels were not reduced significantly.

CONCLUSIONS

Both types of sTNF receptors are elevated in the serum of sarcoidosis patients with active disease, but only the sTNF-R II seems to be useful for monitoring the inflammatory activity of the disease.

Polymorphisms at position -308 in the promoter region of the TNF-alpha and in the first intron of the TNF-beta genes and spontaneous and lipopolysaccharide-induced TNF-alpha release in sarcoidosis

TNF-alpha is a potent pro-inflammatory cytokine. Previous studies have proved that biallelic polymorphisms in the TNF-alpha (-308, TNFA) and TNF-beta genes (intron 1, TNFB) influence TNF-alpha production. In sarcoidosis, a chronic granulomatous disease, as a result of an unknown in vivo activation bronchoalveolar lavage (BAL) cells release high amounts of TNF-alpha, spontaneously and after in vitro stimulation. Thus, sarcoidosis could serve as a model to test the in vivo effect of TNF gene polymorphisms. We determined the TNFA and TNFB polymorphisms of 44 patients with sarcoidosis and found the following allele frequencies: 0.80, 0.20, 0.38 and 0.62 for TNFA1, TNFA2, TNFB1 and TNFB2, respectively. To examine the in vivo effect of the named polymorphisms on the TNF-alpha production, the spontaneous and LPS-induced TNF-alpha release of BAL cells and peripheral blood mononuclear cells were also determined in patients with sarcoidosis. Statistical analysis did not reveal any significant difference between sarcoidosis patients with different genotypes. The results show that TNFA and TNFB polymorphisms do not determine the level of TNF-alpha release of mononuclear cells activated during the course of sarcoid inflammation.