Pathology of sarcoidosis

Advances in cellular and tissue-based imaging techniques for sarcoid granulomas

Sarcoidosis embodies a complex inflammatory disorder spanning multiple systems, with its origin remaining elusive. It manifests as the infiltration of inflammatory cells that coalesce into distinctive noncaseous granulomas within afflicted organs. Unraveling this disease necessitates the utilization of cellular or tissue-based imaging methods to both visualize and characterize the biochemistry of these sarcoid granulomas. Although hematoxylin and eosin stain, standard in routine use alongside cytological stains have found utility in diagnosis within clinical contexts, special stains such as Masson's trichrome, reticulin, methenamine silver, and Ziehl-Neelsen provide additional varied perspectives of sarcoid granuloma imaging. Immunohistochemistry aids in pinpointing specific proteins and gene expressions further characterizing these granulomas. Finally, recent advances in spatial transcriptomics promise to divulge profound insights into their spatial orientation and three-dimensional (3-D) molecular mapping. This review focuses on a range of preexisting imaging methods employed for visualizing sarcoid granulomas at the cellular level while also exploring the potential of the latest cutting-edge approaches like spatial transcriptomics and matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI), with the overarching goal of shedding light on the trajectory of sarcoidosis research.

Establishing a Diagnosis of Pulmonary Sarcoidosis

Pulmonary sarcoidosis is the most prevalent manifestation of sarcoidosis and the commonest diagnosis in clinics for ILD. Due to the lack of a simple and reliable test, making the diagnosis is often challenging. There are three criteria that must always be considered: (1) compatible clinical presentation; (2) evidence of granuloma formation (usually non-caseating); and (3) exclusion of alternative causes of granulomatous disease. There are various tools available for diagnosis, amongst which serum biomarkers like sACE and sIL-2R, HRCT, BAL, EBUS/EUS and sometimes bronchoscopic or surgical lung biopsy are most contributive. However, the degree of invasiveness of the applied test and associated risk to the patient must be weighed against management consequences. In specific situations (e.g., presentation as Löfgren's syndrome) or when there is high suspicion based on HRCT in the context of supportive clinical findings, it might be justifiable to decide on a "working diagnosis of sarcoidosis" and to refrain from further invasive procedures for the patient. This should, however, preferably be agreed upon after discussion in an experienced multidisciplinary team and requires close follow-up of the patient. In general, it is advisable to always maintain a healthy dose of skepticism when making the diagnosis of sarcoidosis, especially when the clinical course of disease gives rise to this.

The Relationship Between Serum Angiotensin Converting Enzyme Level and the Decision to Escalate Treatment of Sarcoidosis

PURPOSE

We performed a retrospective analysis of a sarcoidosis cohort who had sACE obtained at their initial clinic visit, but the treating physician was blinded to the results. We examined the relationship between sACE and the treating physician's decision to escalate sarcoidosis treatment.

METHODS

Treatment was considered escalated if the prednisone dose was increased or if the prednisone dose was not changed but an additional anti-sarcoidosis drug was added or the dose was increased.

RESULTS

561 sarcoidosis patients were analyzed. The most common target organ was the lung (84%). Using a cut-off of > 82 units/L for an elevated sACE, 31/82 (38%) with an elevated sACE had treatment escalation whereas 91/497 (18%) had treatment escalation with a normal sACE (p < 0.0001). For the need of treatment escalation, a sACE (cut-off of > 82) had sensitivity 0.25, specificity 0.89, positive predictive value 0.38, negative predictive value 0.81. These results were not appreciably different using other sACE cut-off values such as 70, 80, 90, or 100. A multivariable logistic regression model that included demographics, the target organ, spirometry results estimated that sACE level and lower FVC were significantly associated with the likelihood of treatment escalation. These findings held when sACE > 82 replaced sACE level in the multivariable logistic regression model.

CONCLUSIONS

Although there was a strong correlation between sACE at the initial sarcoidosis clinic visit and subsequent treatment escalation of sarcoidosis, the predictive power was such that sACE is not adequately reliable to be used in isolation to make this determination.

Clinicopathological Characteristics and Outcomes of Renal Sarcoidosis: A Series Study of 18 Patients from a Single Center

INTRODUCTION

Sarcoidosis is characterized by noncaseating granulomatous inflammation in multiple organs. Renal involvement is rare, and granulomatous interstitial nephritis (GIN) is the predominant histological feature. Renal sarcoidosis (RS) is usually diagnosed by exclusion, combining clinical and histological findings, and often remains misdiagnosed. This retrospective study aimed to describe the characteristics and prognosis of patients with RS in China.

METHODS

Eighteen patients with RS from a single center were enrolled, of whom 15 had biopsy-proven tubulointerstitial nephritis. Their clinicopathological features and renal outcomes were analyzed to understand this rare disease better.

RESULTS

Eighteen patients (14 male/4 female) were included in our study. The median estimated glomerular filtration rate (eGFR) was 30.36 (11.57, 60.14) mL/min/1.73 m2. In 15 patients undergoing a renal biopsy, GIN was the most common pathological phenotype (66.67%). Seventeen patients had follow-up records, with a median follow-up of 24.07 (8.82, 60.90) months. One month after treatment, median eGFR increased significantly from 30.36 (11.57, 60.14) mL/min/1.73 m2 to 58.53 (39.35, 80.65) mL/min/1.73 m2, and proteinuria decreased from 1.10 (0.69, 1.58) g/24 h to 0.68 (0.52, 1.05) g/24 h. No patients relapsed or developed end-stage renal disease.

CONCLUSION

RS is a rare but important cause of tubulointerstitial injury, with a favorable long-term prognosis if properly diagnosed and treated promptly.

The management of sarcoidosis in the 2020's by the primary care physician

Sarcoidosis is an idiopathic granulomatous disease that occurs worldwide and may affect any organ. Because the presenting symptoms of sarcoidosis are not specific for the disease, the primary care physician is usually the first provider to assess these patients. In addition, patients who have previously been diagnosed with sarcoidosis are usually followed longitudinally by primary care physicians. Therefore, these physicians are often the first to address sarcoidosis patient symptoms related to exacerbations of the disease, as well as first observe complications of sarcoidosis medications. This article outlines the approach to the evaluation, treatment and monitoring of sarcoidosis patients by the primary care physician.

Pulmonary Sarcoidosis: Diagnosis and Differential Diagnosis

Sarcoidosis is a multisystem disorder of unknown origin and poorly understood pathogenesis that predominantly affects lungs and intrathoracic lymph nodes and is characterized by the presence of noncaseating granulomatous inflammation in involved organs. The disease is highly heterogeneous and can mimic a plethora of other disorders, making diagnosis a challenge even for experienced physicians. The evolution and severity of sarcoidosis are highly variable: many patients are asymptomatic and their disease course is generally benign with spontaneous resolution. However, up to one-third of patients develop chronic or progressive disease mainly due to pulmonary or cardiovascular complications that require long-term therapy. The diagnosis of sarcoidosis requires histopathological evidence of noncaseating granulomatous inflammation in one or more organs coupled with compatible clinical and radiological features and the exclusion of other causes of granulomatous inflammation; however, in the presence of typical disease manifestations such as Löfgren’s syndrome, Heerfordt’s syndrome, lupus pernio and asymptomatic bilateral and symmetrical hilar lymphadenopathy, the diagnosis can be established with high level of certainty on clinical grounds alone. This review critically examines the diagnostic approach to sarcoidosis and emphasizes the importance of a careful exclusion of alternative diagnoses.

Pathology of Granulomatous Pulmonary Diseases

CONTEXT.—

Because granulomas are represented in almost every disease category, the number of clinically and pathologically important granulomatous pulmonary diseases is large. Their diagnosis by pathologists is particularly challenging because of their nonspecificity. A specific diagnosis can be achieved only when a granuloma-inciting agent(s) (eg, acid-fast bacilli, fungi, foreign bodies, etc) are identified microscopically or by culture; this does not occur in most cases. Furthermore, a specific diagnosis cannot be reached in a high percentage of cases. Although sarcoidosis and infectious diseases account for approximately half of pulmonary granulomatous diseases worldwide, there is significant geographic variation in their prevalence.

OBJECTIVES.—

To present updated information to serve as a guide to pathologic diagnosis of pulmonary granulomatous diseases, to address some commonly held misconceptions and to stress the importance of multidisciplinary coordination. Presentation of basic aspects of granulomas is followed by discussion of specific disease entities, such as tuberculous and nontuberculous Mycobacterial infections, fungal, bacterial, and parasitic infections, sarcoidosis, necrotizing sarcoid granulomatosis, berylliosis, hypersensitivity pneumonitis, hot tub lung, rheumatoid nodule, bronchocentric granulomatosis, aspirated, inhaled, and embolized foreign bodies, drug-induced granulomas, chronic granulomatous disease, common variable immunodeficiency, and granulomatous lesions associated with various types of cancer.

DATA SOURCES.—

Review of pertinent medical literature using the PubMed search engine and the author's practical experience.

CONCLUSIONS.—

Although the diagnosis of granulomatous lung diseases continues to present significant challenges to pathologists, the information presented in this review can be helpful in overcoming them. The importance of multidisciplinary coordination in cases where morphologic diagnosis is not possible cannot be overstated.

New advances in the management of pulmonary sarcoidosis

Sarcoidosis is a highly variable granulomatous multisystem syndrome. It affects individuals in the prime years of life; both the frequency and severity of sarcoidosis are greater in economically disadvantaged populations. The diagnosis, assessment, and management of pulmonary sarcoidosis have evolved as new technologies and therapies have been adopted. Transbronchial needle aspiration guided by endobronchial ultrasound has replaced mediastinoscopy in many centers. Advanced imaging modalities, such as fluorodeoxyglucose positron emission tomography scanning, and the widespread availability of magnetic resonance imaging have led to more sensitive assessment of organ involvement and disease activity. Although several new insights about the pathogenesis of sarcoidosis exist, no new therapies have been specifically developed for use in the disease. The current or proposed use of immunosuppressive medications for sarcoidosis has been extrapolated from other disease states; various novel pathways are currently under investigation as therapeutic targets. Coupled with the growing recognition of corticosteroid toxicities for managing sarcoidosis, the use of corticosteroid sparing anti-sarcoidosis medications is likely to increase. Besides treatment of granulomatous inflammation, recognition and management of the non-granulomatous complications of pulmonary sarcoidosis are needed for optimal outcomes in patients with advanced disease.

Optimized angiotensin-converting enzyme activity assay for the accurate diagnosis of sarcoidosis

BACKGROUND

Serum angiotensin-converting enzyme (ACE) activity determination can aid the early diagnosis of sarcoidosis. We aimed to optimize a fluorescent kinetic assay for ACE activity by screening the confounding effects of endogenous ACE inhibitors and interfering factors. Genotype-dependent and genotype-independent reference values of ACE activity were established, and their diagnostic accuracies were validated in a clinical study.

METHODS

Internally quenched fluorescent substrate, Abz-FRK(Dnp)P-OH was used for ACE-activity measurements. A total of 201 healthy individuals and 59 presumably sarcoidotic patients were enrolled into this study. ACE activity and insertion/deletion (I/D) genotype of the ACE gene were determined.

RESULTS

Here we report that serum samples should be diluted at least 35-fold to eliminate the endogenous inhibitor effect of albumin. No significant interferences were detected: up to a triglyceride concentration of 16 mM, a hemoglobin concentration of 0.71 g/L and a bilirubin concentration of 150 μM. Genotype-dependent reference intervals were considered as 3.76-11.25 U/L, 5.22-11.59 U/L, 7.19-14.84 U/L for II, ID and DD genotypes, respectively. I/D genotype-independent reference interval was established as 4.85-13.79 U/L. An ACE activity value was considered positive for sarcoidosis when it exceeded the upper limit of the reference interval. The optimized assay with genotype-dependent reference ranges resulted in 42.5% sensitivity, 100% specificity, 100% positive predictive value and 32.4% negative predictive value in the clinical study, whereas the genotype-independent reference range proved to have inferior diagnostic efficiency.

CONCLUSIONS

An optimized fluorescent kinetic assay of serum ACE activity combined with ACE I/D genotype determination is an alternative to invasive biopsy for confirming the diagnosis of sarcoidosis in a significant percentage of patients.

Reprint of: The pathology of pulmonary sarcoidosis: update

Sarcoidosis is a multi-system disease of unknown etiology, usually affecting the respiratory tract and other organs, and is characterized by the formation of nonnecrotizing epithelioid granulomas. The diagnosis depends on a combination of a typical clinicoradiological presentation, the finding of nonnecrotizing epithelioid granulomas in a tissue biopsy, and exclusion of other possible diseases, especially those of infectious etiology. The granulomas contain epithelioid cells, giant cells, CD4+ T cells in their center, and CD8+ T lymphocytes and B lymphocytes at their periphery. The granulomas are present in a lymphatic pattern around bronchovascular structures and, because of this, may show angioinvasion. The bronchial involvement produces a high diagnostic yield for transbronchial and endobronchial biopsies in this disease. Finally, small amounts of fibrinoid necrosis may occur within granulomas of sarcoidosis and do not exclude the diagnosis. Larger amounts suggest either infection or the rare disease necrotizing sarcoid granulomatosis (NSG). A number of cytoplasmic structures/inclusions can be identified within the granulomas of sarcoidosis, including asteroid bodies, Schaumann's bodies, calcium oxalate crystals, and Hamazaki-Wesenberg bodies; the last two of these can cause difficulties in differential diagnosis. Extra-pulmonary sarcoid can be an important factor in prognosis. Involved sites include (in decreasing frequency): skin, endocrine organs, extra-thoracic lymph nodes, neurologic sites, eyes, liver, spleen, bone marrow, cardiac, ear/nose/throat, parotid/salivary, muscles, bones/joint, and kidney. NSG is a controversial variant of sarcoidosis consisting of granulomatous pneumonitis with sarcoid-like granulomas, variable amounts of necrosis, and granulomatous vasculitis. The lesions are most often confined to lung, and they usually appear as multiple nodules or nodular infiltrates, but occasionally as solitary or unilateral nodules ranging up to 5 cm in diameter. Nodular sarcoidosis is rare, varying from 1.6% to 4% of patients with sarcoidosis, and, as the name suggests, it shows radiographic nodules measuring 1 to 5 cm in diameter that typically consist of coalescent granulomas. Lung transplantation can be used in selected patients with fibrotic late-stage sarcoidosis. There is a high reported frequency of recurrence of disease in the pulmonary allograft, ranging from 47% to 67%, but recurrence is usually not clinically significant. Studies of the pathogenesis of sarcoidosis suggest that it is a chronic immunological response produced by a genetic susceptibility and exposure to specific environmental factors.

Relationship between CT activity score with lung function and the serum angiotensin converting enzyme in pulmonary sarcoidosis on chest HRCT

To address the reliability of CT activity score (CTAS) and investigate the relationships between CTAS, lung function changes after treatment and the serum angiotensin-converting enzyme (SACE) levels.Fifty-seven sarcoidosis patients underwent chest high-resolution CT (HRCT) and spirometry, as well as SACE examination, were retrospectively analyzed. Follow-up spirometry in each patient was obtained about 6 months after the initial spirometry. The correlations between CTAS and pulmonary function changes were evaluated by Spearman correlation analysis. According to SACE status, patients were divided into normal and high level 2 subgroups. Comparisons of pulmonary function parameters, HRCT abnormalities extent scores between SACE normal and high 2 subgroups were performed with the Mann-Whitney U test or Independent samples t test.CTAS demonstrated significant correlations with lung function changes (Δ%VC: ρ= 0.543, P < .001; ΔFEV1.0/FVC:ρ = 0.417, P = .001; Δ%TLC: ρ = 0.309, P = .019). In addition, worse initial lung function, larger changes of lung function, and higher extent scores of HRCT were observed in SACE high-level subgroup.The findings of this study suggest that CTAS of initial HRCT is a promising index for disease activity in pulmonary sarcoidosis to some degree. Prospective studies with large cohort designed to address further verification are warranted before wide clinical practice.

The Role of Endoscopic Sinus Surgery in Chronic Sinonasal Sarcoidosis

The aim of this study was to define a role for endoscopic sinus surgery (ESS) in the treatment of chronic sinonasal sarcoidosis. All patients seen for sinonasal sarcoidosis in an otolaryngology practice in a tertiary care center from 1991 to 2000 were reviewed. Of 86 patients, 6 were treated with ESS for an operative rate of 7%. Surgeries were performed on those patients with significant sinonasal anatomic blockage. This included nasal obstruction from nasal polyposis and chronic and recurrent acute sinusitis from granulomatous lesions of the ostiomeatal complex. Patients remained symptom free for years after surgery on a nasal steroid regimen. Endoscopic sinus surgery is a viable treatment for those few patients with nasal obstruction or chronic sinusitis due to anatomic blockage from sinonasal sarcoidosis. Although it does not eradicate the disease or prevent recurrence, it does markedly improve quality of life by relieving severe symptoms and reducing the need for systemic steroids. This is the first study to advocate a role for surgery in sinonasal sarcoidosis beyond biopsy and management of complications. Although it may not be the appropriate approach for every patient, ESS certainly should be considered in the treatment options.

Pulmonary sarcoidosis with and without extrapulmonary involvement: a cross-sectional and observational study in China

OBJECTIVES

Sarcoidosis is a multisystem disease characterised by the formation of granulomas within various organs, mainly the lungs. Several studies from different countries have been undertaken to investigate sarcoidosis with extrapulmonary involvement except from China. The objective of this study is to investigate a comparative clinical analysis in patients with pulmonary sarcoidosis with and without extrapulmonary involvement from China.

METHODS

Data from inpatients diagnosed with sarcoidosis at Shanghai Pulmonary Hospital (Shanghai, China) between January 2009 and December 2014 were retrospectively collected and analysed. Six hundred and thirty-six patients with biopsy-proven sarcoidosis were included in the study, including 378 isolated pulmonary sarcoidosis and 258 pulmonary sarcoidosis plus extrapulmonary involvement.

RESULTS

Two hundred and fifty-eight (40.6%) patients with pulmonary sarcoidosis had extrapulmonary involvement. Extrapulmonary localisations were detected mostly in extrathoracic lymph nodes (n=147) and skin (n=86). Statistically significant differences were demonstrated between patients with pulmonary sarcoidosis plus extrapulmonary involvement and patients with isolated pulmonary sarcoidosis for fatigue (16.6%vs8.3%, P<0.05), serum ACE (SACE) levels (79.0±46.9 IU/L vs 69.7±38.7 IU/L, P<0.05), and high-resolution CT (HRCT) findings (53.8%vs46.2%, P<0.05).

CONCLUSIONS

Extrapulmonary involvement is common in patients with pulmonary sarcoidosis, with the most common sites being extrathoracic lymph nodes and skin. Patients with sarcoidosis with extrapulmonary involvement are more symptomatic (fatigue), have higher SACE levels and more deteriorating HRCT findings, to which clinicians should pay attention.

Non-neoplastic histiocytic and dendritic cell disorders in lymph nodes

Benign and malignant proliferations of histiocytes and dendritic cells may be encountered in lymph nodes. Reactive histiocytic and dendritic cell infiltrates occur in response to diverse stimuli and in addition to causing lymphadenopathy, may be present unexpectedly in lymph nodes excised for other indications. This review summarizes the pathogenesis and histopathological features of the various non-neoplastic histiocytic and dendritic cell infiltrates that can occur in lymph nodes.

RNA-sequencing Identifies Novel Pathways in Sarcoidosis Monocytes

Sarcoidosis is a complex systemic granulomatous disorder of unknown etiology. Genome-wide association studies have not been able to explain a causative role for nucleotide variation in its pathogenesis. The goal of the present study was to identify the gene expression profile and the cellular pathways altered in sarcoidosis monocytes via RNA-sequencing. Peripheral blood monocytes play a role in sarcoidosis inflammation. Therefore, we determined and compared the transcriptional signature of monocytes from peripheral blood from sarcoidosis patients and healthy controls via RNA-sequencing. We found 2,446 differentially expressed (DE) genes between sarcoidosis and healthy control monocytes. Analysis of these DE genes showed enrichment for ribosome, phagocytosis, lysosome, proteasome, oxidative phosphorylation and metabolic pathways. RNA-sequencing identified upregulation of genes involved in phagocytosis and lysosomal pathway in sarcoidosis monocytes, whereas genes involved in proteasome degradation and ribosomal pathways were downregulated. Further studies are needed to investigate the role of specific genes involved in the identified pathways and their possible interaction leading to sarcoidosis pathology.

Biomarkers in sarcoidosis

INTRODUCTION

Numerous biomarkers have been evaluated for the diagnosis, assessment of disease activity, prognosis, and response to treatment in sarcoidosis. In this report, we discuss the clinical and research utility of several biomarkers used to evaluate sarcoidosis. Areas covered: The sarcoidosis biomarkers discussed include serologic tests, imaging studies, identification of inflammatory cells and genetic analyses. Literature was obtained from medical databases including PubMed and Web of Science. Expert commentary: Most of the biomarkers examined in sarcoidosis are not adequately specific or sensitive to be used in isolation to make clinical decisions. However, several sarcoidosis biomarkers have an important role in the clinical management of sarcoidosis when they are coupled with clinical data including the results of other biomarkers.

Sarcoidosis mimicking lymphoma on FDG-PET imaging

Sarcoidosis is an inflammatory, systemic disease characterized by noncaseating granulomas. We describe a case of a 52-year-old female who presented with fevers, chills, night sweats, and weight loss of four months' duration. Lymphoma was suspected, and results of advanced imaging procedures were also consistent with lymphoma. However, mediastinal lymph-node biopsy, bone-marrow aspiration, and biopsy revealed noncaseating granulomas. She was diagnosed with sarcoidosis and had a positive therapeutic response to drug therapy. This case study illustrates that sarcoidosis can be a pitfall in 18-F-fluorodeoxyglucose (FDG) positron emission tomography (PET) imaging, which may lead to false-positive diagnosis of malignancy. PET-positive lesions do not always indicate malignancy, and histological confirmation of the lesions with biopsy should always be performed.

Acute renal failure as a form of presentation of sarcoidosis in a young adult: a case report

INTRODUCTION

Sarcoidosis is a systemic granulomatous disease. Renal involvement is a rare initial presentation of this disease. Few articles on renal involvement as an initial presentation of sarcoidosis have been published in the literature.

CASE PRESENTATION

A 26-year-old Caucasian woman presented with acute renal failure as an initial manifestation of sarcoidosis.

CONCLUSIONS

Renal involvement is an uncommon feature of sarcoidosis and it is essential to establish a fast and correct diagnosis because early therapy avoids progression to terminal renal failure.

Renal sarcoidosis with limited lung manifestations expressing Propionibacterium acnes antigens in the affected tubulointerstitium

Sarcoidosis is a granulomatous multisystemic disorder of unknown origin that can affect the kidneys. Previous reports from Japan and Europe have indicated a link between Propionibacterium acnes infections and sarcoidosis. Here, we present the case of a 68-year-old woman with hypercalcemia and renal failure. A kidney biopsy was performed, which showed granulomatous tubulointerstitial nephritis with a large nonnecrotic nodule that contained mononuclear inflammatory cells and multinucleated giant cells. Subsequent immunohistochemical analysis revealed intracytoplasmic structures, which strongly indicated the presence of the P acnes antigen. Treatment with methylprednisolone ameliorated the patient's hypercalcemia and renal failure. This case report emphasizes the potential of chronic P acnes infection to cause sarcoidosis.

Granulomatous interstitial nephritis in a renal allograft

We describe a middle-aged woman in whom granulomatous interstitial nephritis (GIN) developed in a renal allograft. She had undergone bowel resection due to an uncertain diagnosis of active granulomatous bowel disease 30 years earlier. Thereafter, frequent hyperoxaluria as well as calcium oxalate stone and recurrent urinary tract infections had resulted in a progressive deterioration in kidney function over a period of 20 years. She underwent living donor kidney transplantation; however, her kidney function progressively deteriorated, despite transplantation. A biopsy of the renal allograft revealed GIN with granulomatous vasculitis accompanied by calcium oxalate crystals. These as well as the laboratory findings indicated a diagnosis of sarcoidosis. We considered that the aggravated granulomatous inflammation on the allograft was caused by recurrent sarcoidosis accompanied by hyperoxaluria.

Sarcoidosis and interstitial pulmonary fibrosis; two distinct disorders or two ends of the same spectrum

PURPOSE OF REVIEW

Pulmonary fibrosis is a reparative response characterized by accumulation of extracellular matrix in the lung parenchyma that may be observed in end-stage sarcoidosis. This article will discuss the recent advancements in the understanding of the pathogenesis of pulmonary fibrosis in sarcoidosis in comparison with idiopathic pulmonary fibrosis (IPF)/usual interstitial pneumonia (UIP).

RECENT FINDINGS

A recent study examined clinical, radiographic, and histopathologic findings of end-stage sarcoidosis patients with lung fibrosis who underwent lung transplantation. The authors found many of the patients to have moderate-to-severe interstitial pneumonitis in some cases with UIP considered to be atypical of end-stage sarcoidosis. Furthermore, these patients had diagnosis of sarcoidosis for a shorter time prior to transplant compared with individuals without interstitial pneumonitis (mean 4.8 years vs. 23.3 years). Another study found a promoter polymorphism in prostaglandin-endoperoxide synthase 2 (PTGS2), -765G>C, to be associated with susceptibility and increased risk for pulmonary fibrosis in sarcoidosis in the white population compared with healthy controls. An altered Sp1/Sp3 binding to the -765 region has been proposed as a possible mechanism for reduced PTGS2 expression.

SUMMARY

A subset of patients with sarcoidosis that progresses to pulmonary fibrosis may share some similar mechanistic and morphologic aberrations with IPF/UIP. Future studies are needed to examine the significance of chronic interstitial pneumonitits and UIP pattern in fibrotic sarcoidosis as a potential marker for progressive disease, and the roles of PTGS2 polymorphism in various ethnic groups and Sp1/Sp3 binding in other fibrotic lung diseases.

The BTNL2 A allele variant is frequent in Danish patients with sarcoidosis

BACKGROUND

The butyrophilin-like 2 (BTNL2) gene is located on chromosome 6p21.3 close to the HLA-class II genes. An association has been reported between sarcoidosis and a single nucleotide polymorphism in BTNL2, rs2076530, also termed the A allele.

OBJECTIVES

To evaluate whether patients with sarcoidosis carry the A allele more frequently than healthy subjects.

METHODS

The series comprised 87 ethnic Danes with sarcoidosis and 113 healthy control subjects. Analysis of rs2076530 was performed by Taqman assay, polymerase chain reaction and sequencing of genomic DNA.

RESULTS

Sarcoidosis patients had a higher frequency of the A allele than controls (73.9% vs 55.8%) (P < 0.025). The frequency of GG, GA and AA genotype was 5.7%, 40.2% and 54.0% in patients vs 16.0%, 56.6% and 27.4% in controls (P < 0.001). The AA genotype was associated with increased risk of sarcoidosis in both a dominant [odds ratio (OR) 3.1; 95% confidence interval (CI) 1.1-8.7; P < 0.03] and a recessive model (OR 3.1; 95% CI 1.72-5.61; P < 0.001). Population attributable fraction for disease was 50% in a dominant model and 25% in a recessive model.

CONCLUSIONS

The BTNL2 A allele variant occurs with a high frequency in Danish patients with sarcoidosis and the AA genotype is associated with a ∼threefold higher risk of sarcoidosis than the GG genotype. Our results should encourage future studies on the interrelationship between the BTNL2 protein and granuloma formation in sarcoidosis.

Molecular Basis of Pulmonary Disease

Pulmonary pathology includes a large spectrum of both neoplastic and non-neoplastic diseases that affect the lung. Many of these are a result of the unusual relationship of the lung with the outside world. Every breath that a human takes brings the outside world into the body in the form of infectious agents, organic and inorganic particles, and noxious agents of all types. Although the lung has many defense mechanisms to protect itself from these insults, these are not infallible; therefore, lung pathology arises. Damage to the lung is particularly important given the role of the lung in the survival of the organism. Any impairment of lung function has widespread effects throughout the body, since all organs depend on the lungs for the oxygen they need. Pulmonary pathology catalogs the changes in the lung tissues and the mechanisms through which these occur. This chapter presents a review of lung pathology and the current state of knowledge about the pathogenesis of each disease. It suggests that a clear understanding of both morphology and mechanism is required for the development of new therapies and preventive measures.

The diagnosis of sarcoidosis

The diagnosis of sarcoidosis can never be assured: sarcoidosis is a diagnosis of exclusion and this cannot be accomplished with complete confidence. The diagnosis requires clinicoradiographic findings compatible with the diagnosis, histologic confirmation of granulomatous inflammation, exclusion of known causes of granulomatous disease, and evidence of disease in at least two organs. The end result of this diagnostic evaluation for sarcoidosis is neither a definitive diagnosis nor an exclusion of the diagnosis, but rather a statistical likelihood of the disease.

[Extra-thoracic sarcoidosis]

Sarcoidosis is a multisystemic granulomatous disease of unknown aetiology, characterized by the presence of non-caseating epithelioid cell granulomas on tissue biopsy of affected organs. It may involve any organ, presenting in multiple forms to clinicians of different specialties. In its extra-thoracic form it may involve the liver (50-80%), spleen (40-80%), eye (20-50%), extrathoracic lymph nodes (30%), skin (25%), nervous system (10%), heart (5%), kidney, muscle and bone, sometimes without symptoms. The presence of extrathoracic disease may affect the prognosis and treatment options for sarcoidosis. The authors present a review of the major extra-thoracic manifestations of sarcoidosis regarding its clinical presentation, diagnosis, treatment, follow-up and prognosis.

The pathology of pulmonary sarcoidosis: update

Sarcoidosis is a multi-system disease of unknown etiology, usually affecting the respiratory tract and other organs, and is characterized by the formation of nonnecrotizing epithelioid granulomas. The diagnosis depends on a combination of a typical clinicoradiological presentation, the finding of nonnecrotizing epithelioid granulomas in a tissue biopsy, and exclusion of other possible diseases, especially those of infectious etiology. The granulomas contain epithelioid cells, giant cells, CD4+ T cells in their center, and CD8 + T lymphocytes and B lymphocytes at their periphery. The granulomas are present in a lymphatic pattern around bronchovascular structures and, because of this, may show angioinvasion. The bronchial involvement produces a high diagnostic yield for transbronchial and endobronchial biopsies in this disease. Finally, small amounts of fibrinoid necrosis may occur within granulomas of sarcoidosis and do not exclude the diagnosis. Larger amounts suggest either infection or the rare disease necrotizing sarcoid granulomatosis (NSG). A number of cytoplasmic structures/inclusions can be identified within the granulomas of sarcoidosis, including asteroid bodies, Schaumann's bodies, calcium oxalate crystals, and Hamazaki-Wesenberg bodies; the last two of these can cause difficulties in differential diagnosis. Extra-pulmonary sarcoid can be an important factor in prognosis. Involved sites include (in decreasing frequency): skin, endocrine organs, extra-thoracic lymph nodes, neurologic sites, eyes, liver, spleen, bone marrow, cardiac, ear/nose/throat, parotid/ salivary, muscles, bones/joint, and kidney. NSG is a controversial variant of sarcoidosis consisting of granulomatous pneumonitis with sarcoid-like granulomas, variable amounts of necrosis, and granulomatous vasculitis. The lesions are most often confined to lung, and they usually appear as multiple nodules or nodular infiltrates, but occasionally as solitary or unilateral nodules ranging up to 5 cm in diameter. Nodular sarcoidosis is rare, varying from 1.6% to 4% of patients with sarcoidosis, and, as the name suggests, it shows radiographic nodules measuring 1 to 5 cm in diameter that typically consist of coalescent granulomas. Lung transplantation can be used in selected patients with fibrotic late-stage sarcoidosis. There is a high reported frequency of recurrence of disease in the pulmonary allograft, ranging from 47% to 67%, but recurrence is usually not clinically significant. Studies of the pathogenesis of sarcoidosis suggest that it is a chronic immunological response produced by a genetic susceptibility and exposure to specific environmental factors.

Sarcoidosis presenting with hearing loss and granulomatous interstitial nephritis in an adolescent

Granulomatous interstitial nephritis is an uncommon finding in a kidney biopsy. The differential diagnosis is broad and includes infections, drug exposure, and sarcoidosis. Sarcoidosis, a systemic disorder of unknown etiology characterized by the presence of noncaseating granulomata in affected organs, is rare in children. We discuss an adolescent boy with the unusual presentation of granulomatous interstitial nephritis and acute deafness. Sarcoidosis should be considered as part of the differential diagnosis for children and adolescents with hearing loss and kidney disease.

Oral sarcoidosis: a review of literature

Sarcoidosis is a common systemic granulomatous disease affecting multiple organs. Oral involvement is relatively rare and, to our knowledge, there have been only 64 cases reported in the English literature. Most cases of oral sarcoidosis present with mobility of the teeth due to rapid alveolar bone loss. Other oral manifestations include asymptomatic swelling of the involved mucosa, gingivitis and ulcers. Diagnosis of sarcoidosis is by exclusion as no specific test is available. Radiographic, biochemical and histological findings are non-specific, but helpful. All cases of sarcoidosis do not require treatment. Corticosteroids are the treatment of choice in patients requiring treatment. Other drugs such as chloroquine, methotrexate, infliximab and thalidomide are also used in the treatment of sarcoidosis. In most of the oral cases reported, systemic steroids and surgery were the preferred treatment.

Etanercept for the treatment of stage II and III progressive pulmonary sarcoidosis

BACKGROUND

Tumor necrosis factor (TNF)-alpha is produced by macrophages and other cells, and is believed to participate in granulomatous inflammation. Targeted antagonism of TNF-alpha has been proposed as a novel treatment strategy for sarcoidosis. Etanercept is a dimeric fusion protein that binds specifically to TNF-alpha, rendering it biologically inactive.

OBJECTIVE

To assess whether etanercept has potential efficacy in the treatment of progressive pulmonary sarcoidosis.

DESIGN

Prospective, open-label, phase-2 treatment trial.

SETTING

Mayo Clinic, Rochester, MN.

PATIENTS

Stage II or III progressive pulmonary sarcoidosis.

INTERVENTION

Etanercept, 25 mg subcutaneously twice weekly.

MEASUREMENTS

Pulmonary function, chest radiographs, dyspnea, and TNF-alpha levels in serum and BAL fluid.

RESULTS

The study was terminated after the enrollment of 17 patients due to an early-stop clause of the pretrial study design related to excessive treatment failures. Neither absolute levels of TNF-alpha nor TNF-alpha activity in the serum, BAL fluid, or alveolar macrophages were able to predict which patients would respond to etanercept.

CONCLUSIONS

In patients with progressive stage II or III pulmonary sarcoidosis, etanercept was frequently associated with early or late treatment failure. These data would not support the design of a large multicenter randomized trial comparing etanercept with conventional corticosteroid therapy.

Liver and kidney diseases

The spectrum of renal disease in patients with liver disease is expanding. The recognition of renal complications of liver diseases is essential in the management of these patients. As liver transplantation is a treatment option for many patients with chronic liver disease, the presence of renal complications impacts the decision regarding transplantation and influences the course of these patients after transplantation, especially with regard to the use of immunosuppressive therapy. The involvement of the liver and kidney in systemic conditions is common and adds to the morbidity and mortality of patients.

The pathology of sarcoidosis

Sarcoidosis is a multisystemic disease characterized by a nonnecrotizing granulomatous inflammatory process that can progress through various stages of activity. The distinctive histology of sarcoidosis is often associated with various morphologic findings in the lung and other organs. The rare variants, necrotizing sarcoidal granulomas and nodular sarcoidosis, share some of the histologic features of typical sarcoidosis, but may have different clinical and pathologic manifestations. The clinician and pathologist should be aware of the diverse pathologic appearances of sarcoidosis.

Diagnostic criteria for sarcoidosis of the sinuses

BACKGROUND

Although newer technologies facilitate its diagnosis and treatment, little is known about sarcoidosis of the paranasal sinuses.

OBJECTIVES

We sought to better characterize sarcoidosis of the sinuses and establish criteria for diagnosis.

METHODS

Case-finding criteria were established, and over 50 reports of sarcoidosis of the sinuses in the medical literature were reviewed. Nine case reports of patients fulfilling the case-finding criteria were identified, as were 6 additional patients from our clinics.

RESULTS

Nasal obstruction and chronic sinusitis were the usual initial complaints from patients and were associated with mucosal crusting, studding, plaque-like changes, or polyps in the nose in 5 of 6 of our patients. The most consistent finding in nose and sinuses was an erythematous, edematous, friable, hypertrophied mucosa. Like 5 of 6 of our patients, most patients had extra-pulmonary sarcoidosis involving multiple organs, but some had isolated upper respiratory disease. Radiologic studies showed extensive and often complete opacification of the sinuses and nose similar to that seen in diffuse polyposis associated with chronic bacterial and fungal sinusitis. No specific histopathologic findings distinguished sinus disease from those reported with pulmonary involvement. Pharyngeal involvement was present in 2 case reports and caused the apparent asphyxiation of 1 of our patients.

CONCLUSION

Sarcoidosis of the sinuses should be considered in the differential diagnosis of sinusitis, especially in association with nasal polyposis, even when the sarcoidosis has not been otherwise diagnosed. On the basis of this experience, we propose diagnostic criteria for sarcoidosis of the sinuses. These include (1) radiologic evidence of sinusitis, (2) histopathologic confirmation of noncaseating granuloma in the sinus tissue supported by negative stains for fungus and acid-fast bacilli, (3) negative serologic test results for syphilis and antineutrophil cytoplasmic antibodies, and (4) no clinical evidence of other disease processes associated with granulomatous nasal and sinus inflammation. These criteria will provide the basis for further studies to assess both the natural history and the effectiveness of treatment in sarcoidosis of the sinuses.

The clinical management of sarcoidosis. A 50-year experience at the Johns Hopkins Hospital

Sarcoidosis is an enigmatic disease with extremely variable manifestations in pattern, severity and course. Since Longcope and Freiman's descriptive monograph in 1952 (50) summarizing the clinical findings of the first half of this century, new dimensions of assessing the disease and treatment have been added. The impact of corticosteroids is central. The present review extends the studies to the second half of this century. Earlier diagnosis is facilitated and treatment often reverses many of the disease manifestations and improves the quality and extent of life for the patient. The management issues and guidelines outlined in this paper for both intrathoracic and extrathoracic disease are based on several longitudinal studies of the sarcoidosis patients summarized here, and 50 years of clinical experience by the senior author (CJJ) at Johns Hopkins Hospital, a tertiary referral center with an active Sarcoid Clinic. Case reports are presented in the appendix. It is clear that corticosteroids are the most effective therapeutic agent for sarcoidosis, usually with impressive and prompt response. This represents the dramatic difference in this disease after 1950. No more specific or effective immunosuppressive or antiinflammatory agents have been identified. Undesirable side effects are minimal if excessive doses are avoided. The effectiveness of "steroid-sparing agents" such as methotrexate is uncertain. Although irreversible tissue damage from the disease may limit the effectiveness of treatment, benefits of corticosteroids greatly exceed the negative side effects. Since spontaneous remissions without treatment do occur, a period of observation of 2 years are more is warranted if the patient is relatively asymptomatic. Gradual radiographic progression for 2 or more years, even without major symptoms or reduction in pulmonary function, indicates the need for a trial of corticosteroid treatment, especially in white patients where symptoms may lag behind the radiographic changes. Relapses as treatment is withdrawn are frequent, especially in African-American patients, who tend to have more severe and more prolonged disease than white patients. A minimum of 1 year of treatment is recommended unless no improvement is noted after 3 months. Continued low-dose prednisone at daily doses of 10-15 mg is helpful in preventing relapses and further progression of disease. Periodic attempts at tapering are justified. Repeated relapses may indicate the need for life-long treatment. When irreversible changes are present, especially in the presence of chronic fibrotic disease, changing goals of treatment to provide optimal supportive care may represent better management than having unrealistic expectations from increased corticosteroid dosage or the addition of other potentially toxic immunosuppressive agents. Many agents related to sarcoidosis require further research. The most important question facing sarcoid researchers today is etiology. It is difficult to design specific therapy when the fundamental causes and disease mechanisms are not established. Rather than being a single disease with a single cause, it is possible that a number of genetic factors and environmental or infectious agents may result in an immune response that is manifested as sarcoidosis. Understanding basic causal mechanisms may help explain the varied disease manifestations and aid in designing curative treatments. Such etiologic questions should be explored from both a basic science and an epidemiologic approach. Therapeutic trials of new drugs such as pentoxyfylline and possibly thalidomide are needed to address their potential as well as limitations of steroid therapy. Finally, for patients who have progressed to organ failure, the problems of sarcoid recurrence in transplanted tissue, increased allograft rejection, and long-term prognosis of solid organ transplants have yet to be resolved. (ABSTRACT TRUNCATED)