Assessment of mycobacterial, propionibacterial, and human herpesvirus 8 DNA in tissues of greek patients with sarcoidosis

Dilemma of diagnosing thoracic sarcoidosis in tuberculosis endemic regions: An imaging-based approach. Part 1

Sarcoidosis is a multi-systemic disorder of unknown etiology, although commonly believed to be immune-mediated. Histologically, it is characterized by noncaseating granuloma which contrasts against the caseating granuloma seen in tuberculosis (TB), an infectious disease that closely mimics sarcoidosis, both clinically as well as radiologically. In TB-endemic regions, the overlapping clinico-radiological manifestations create significant diagnostic dilemma, especially since the management options are markedly different in the two entities. Part 1 of this review aims to summarize the clinical, laboratory, and imaging features of sarcoidosis, encompassing both typical and atypical manifestations, in an attempt to distinguish between the two disease entities.

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.

Selected Giant Cell Rich Lesions of the Temporal Bone

Giant cell rich lesions of the temporal bone encompass a wide spectrum of disease that includes infectious, reactive, and neoplastic processes. When dealing with any lesion that can potentially involve bone, it is important to understand both the clinical presentation and to correlate the histologic findings with the radiologic imaging. This review discusses the clinical, the pathologic features including the differential diagnosis, and the treatment of some of the more commonly encountered giant cell rich entities in this region.

Plasmacytoid dendritic cells in cutaneous sarcoidosis

While absent from normal skin, plasmacytoid dendritic cells (pDCs) infiltrate the skin in several infectious, inflammatory, and neoplastic entities. In addition to providing anti-viral resistance, pDCs link the innate and adaptive immune responses. Sarcoidosis is an idiopathic multi-system granulomatous disease characterized by epitheliod granulomas. Its underlying immunopathogenesis involves hyperactivity of cell-mediated immune system with involvement of CD4+ T-helper cells of the Th1 subtype. Recently, pDCs have been shown to contribute to other cutaneous granulomatous disorders such as granuloma annulare (GA). Here, we intend to investigate pDC occurrence and activity in cutaneous sarcoidosis. Twenty cutaneous sarcoidosis cases and a comparable group of 20 cases of GA were retrieved from our database and were immunohistochemically tested for pDC occurrence and activity using anti-BDCA-2 and anti-MxA antibodies, respectively. Fifteen cases of cutaneous lupus erythrematosus (LE) were used as a comparison group. A semi-quantitative scoring system was used. pDCs were present in all cutaneous sarcoidosis in peri-vascular and/or peri-adnexal location admixed with lymphocytes. pDC numbers in sarcoidosis were comparable to those in GA, while pDCs were significantly more abundant in LE. MxA expression was mostly patchy in cutaneous sarcoidosis and GA cases, while LE cases showed diffuse and strong MxA expression. In conclusion, we have shown that pDCs are recruited into the skin lesions of sarcoidosis and GA. Despite the diminished type I IFN production demonstrated in our study, the consistent presence of pDCs in all cutaneous sarcoidosis cases speaks in favor of some role of these cells in the pathogenesis of granulomatous disorders. (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 55-61).

Spectrum of orocutaneous disease associations: Genodermatoses and inflammatory conditions

The oral cavity and cutaneous organ systems share a close embryologic origin. Therefore, there are numerous dermatologic conditions presenting with concomitant oral findings of which the dermatologist must be aware. The second article in this continuing medical education series reviews inflammatory orocutaneous conditions and a number of genodermatoses. It is essential for dermatologists to be familiar with oral cavity manifestations associated with dermatologic diseases for prompt diagnosis, management, and appropriate referral to stomatology and dentistry.

Orbital tuberculosis: Clinicopathological correlation and diagnosis using PCR in formalin-fixed tissues

This article describes the clinicopathological correlation and challenges encountered in the diagnosis of orbital tuberculosis (TB). Retrospective, interventional case series. A chart review of six patients who underwent biopsy for an orbital mass between January 2012 and December 2013 was performed. Institutional review board approval was obtained for the study. Clinical, radiological, and laboratory findings were documented, and response to antitubercular therapy (ATT) was noted. Age at presentation ranged from 18 to 64 years and duration of complaints varied from 2 weeks to 2 months. Pain, redness, and swelling with an orbital mass on computerized tomography (CT) were the common features. None of the patients was clinically suspected to have orbital TB at presentation. History of prior contact with a patient of TB and history of prior TB were present in one case each. Chest radiography (CXR) showed pulmonary consolidation in one case. Tuberculin skin test (TST) readings ranged from nonreactive to 23 mm. The presence of sputum acid fast bacilli (AFB) was tested in three cases and was negative. Polymerase chain reaction (PCR) for MPB64 gene was positive in all six cases. All cases responded to ATT. Clinical presentation of orbital TB can be variable and can simulate conditions like inflammatory disease and malignancy. Biopsy with histopathology plays a key role in diagnosis. Supportive laboratory investigations are necessary to clinch the diagnosis in cases where histopathology is suggestive of TB. In this regard, PCR for Mycobacterium tuberculosis (MTB) on tissue biopsy specimens may be a sensitive diagnostic tool.

Granulomatous diseases: Kids are not just little people

Granulomatous diseases represent a heterogeneous group of conditions characterized by histiocytic inflammation that affect patients of any age. These diseases differ widely in their pathogenesis and include infectious and noninfectious conditions. This review focuses on noninfectious granulomatous conditions, with particular emphasis on age-related differences in the onset, epidemiology, clinical manifestations, prognosis, and age-specific management of specific granulomatous disorders. Knowledge of age-specific aspects of granulomatous conditions in adults and children improves both the extent of the diagnostic workup and the management of these patients.

The role of pattern recognition receptors in lung sarcoidosis

Sarcoidosis is a granulomatous disorder of unknown etiology. Infection, genetic factors, autoimmunity and an aberrant innate immune system have been explored as potential causes of sarcoidosis. The etiology of sarcoidosis remains unknown, and it is thought that it might be caused by an infectious agent in a genetically predisposed, susceptible host. Inflammation results from recognition of evolutionarily conserved structures of pathogens (Pathogen-associated molecular patterns, PAMPs) and/or from reaction to tissue damage associated patterns (DAMPs) through recognition by a limited number of germ line-encoded pattern recognition receptors (PRRs). Due to the similar clinical and histopathological picture of sarcoidosis and tuberculosis, Mycobacterium tuberculosis antigens such early secreted antigen (ESAT-6), heat shock proteins (Mtb-HSP), catalase-peroxidase (katG) enzyme and superoxide dismutase A peptide (sodA) have been often considered as factors in the etiopathogenesis of sarcoidosis. Potential non-TB-associated PAMPs include lipopolysaccharide (LPS) from the outer membrane of Gram-negative bacteria, peptidoglycan, lipoteichoic acid, bacterial DNA, viral DNA/RNA, chitin, flagellin, leucine-rich repeats (LRR), mannans in the yeast cell wall, and microbial HSPs. Furthermore, exogenous non-organic antigens such as metals, silica, pigments with/without aluminum in tattoos, pesticides, and pollen have been evoked as potential causes of sarcoidosis. Exposure of the airways to diverse infectious and non-infectious agents may be important in the pathogenesis of sarcoidosis. The current review provides and update on the role of PPRs and DAMPs in the pathogenesis of sarcoidsis.

Is there any association between Sarcoidosis and infectious agents?: a systematic review and meta-analysis

Background

During the last few years, investigators have debated the role that infectious agents may have in sarcoidosis pathogenesis. With the emergence of new molecular biology techniques, several studies have been conducted; therefore, we performed a meta-analysis in order to better explain this possible association.

Methods

This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement from the Cochrane collaboration guidelines. Four different databases (Medline, Scopus, Web of Science, and Cochrane Collaboration) were searched for all original articles published from 1980 to 2015. The present meta-analysis included case–control studies that reported the presence of microorganisms in samples of patients with sarcoidosis using culture methods or molecular biology techniques. We used a random effects or a fixed-effect model to calculate the odds ratio (OR) and 95% confidence intervals (CI). Sensitivity and subgroup analyses were performed in order to explore the heterogeneity among studies.

Results

Fifty-eight studies qualified for the purpose of this analysis. The present meta-analysis, the first, to our knowledge, in evaluation of all infectious agents proposed to be associated with sarcoidosis and involving more than 6000 patients in several countries, suggests an etiological link between Propionibacterium acnes and sarcoidosis, with an OR of 18.80 (95% CI 12.62, 28.01). We also found a significant association between sarcoidosis and mycobacteria, with an OR of 6.8 (95% CI 3.73, 12.39). Borrelia (OR 4.82; 95% CI 0.98, 23.81), HHV-8 (OR 1.47; 95% CI 0.02, 110.06) as well as Rickettsia helvetica, Chlamydia pneumoniae, Epstein-barr virus and Retrovirus, although suggested by previous investigations, were not associated with sarcoidosis.

Conclusion

This meta-analysis suggests that some infectious agents can be associated with sarcoidosis. What seems clear is that more than one infectious agent might be implicated in the pathogenesis of sarcoidosis; probably the patient’s geographical location might dictate which microorganisms are more involved. Future investigations and more clinical trials are need to bring these evidences to a more global level.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-016-0332-z) contains supplementary material, which is available to authorized users.

A rare presentation of sarcoidosis with nasal bone involvement

Background:

Sarcoidosis is a multisystem granulomatous inflammatory disease that is induced by infectious or noninfectious environmental antigens in a genetically susceptible host. Tuberculosis and sarcoidosis are two diseases with similar clinical and pathologic findings. The link between these two diseases has been extensively studied.

Objective:

Herein we describe a case of sarcoidosis associated with tuberculosis, treated for tuberculosis, and, 1 year, later presented with a nasal dorsal lump and skin lesions on the extremities.

Methods:

Case report with clinical description.

Results:

Our patient had a history of skin and cervical lymphadenopathy symptoms 1 year earlier and was treated with antituberculosis drugs in an outer medical center. Therapy had cured cervical lymphadenopathies, with no improvement in skin lesions. On appearance of the nasal dorsal lump, she presented to our outpatient clinic. We retrieved the previous specimens of the patient, which revealed coexistence of necrotizing granulomas with non-necrotizing granulomas, which was strongly indicative of the coexistence of tuberculosis and sarcoidosis. Radiologic, histopathologic, and microbiologic investigation revealed the diagnosis of sarcoidosis with nasal, cutaneous, and pulmonary involvement. Treatment with prednisolone and hydroxychloroquine resulted in dramatic improvement of nasal bone, pulmonary, and skin lesions within 2 weeks.

Conclusion:

The clinical presentation of sarcoidosis can be complex, and the differential diagnosis from tuberculosis can be challenging. Atypical clinical pictures also can cause delays in diagnosis and proper management. In patients with granulomatous lesions that are unresponsive to antituberculosis therapy, physicians must be alerted to the possibility of coexistent sarcoidosis.

Real-time quantitative reverse transcription-polymerase chain reaction to detect propionibacterial ribosomal RNA in the lymph nodes of Chinese patients with sarcoidosis

The aim of this study was to investigate the diagnostic value of using the copy number of propionibacterial rRNA as a biomarker for sarcoidosis. Ribosomal RNA of Propionibacterium acnes and P. granulosum was measured by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR) using formalin-fixed and paraffin-embedded tissue of lymph node biopsy from 65 Chinese patients with sarcoidosis, 45 with tuberculosis and 50 controls with other diseases (23 with non-specific lymphadenitis and 27 with mediastinal lymph node metastasis from lung cancer). The receiver operating characteristic (ROC) curve was analysed to determine an optimal cut-off value for diagnosis, and the diagnostic accuracy of the cut-off value was evaluated in additional tissue samples [24 patients with sarcoidosis and 22 with tuberculosis (TB)]. P. acnes or P. granulosum rRNA was detected in 48 of the 65 sarcoidosis samples but only in four of the 45 TB samples and three of the 50 control samples. Analysis of the ROC curve revealed that an optimal cut-off value of the copy number of propionibacterial rRNA for diagnosis of sarcoidosis was 50·5 copies/ml with a sensitivity and specificity of 73·8 and 92·6%, respectively. Based on the cut-off value, 19 of the 24 additional sarcoidosis samples exhibited positive P. acnes or P. granulosum, whereas only one of the 22 additional TB samples was positive, resulting in a sensitivity and specificity of 79·2 and 95·5%, respectively. These findings suggest that propionibacteria might be associated with sarcoidosis granulomatous inflammation. Detection of propionibacterial rRNA by RT-PCR might possibly distinguish sarcoidosis from TB.

Cutaneous sarcoidosis: an intriguing model of immune dysregulation

Sarcoidosis is a systemic granulomatous disease characterized by the presence of non-caseating granulomas. Its etiology remains obscure. A plausible hypothesis suggests that a complex interplay of host factors, infectious processes, and non-infectious environmental factors, matched with a susceptible genetic background, results in a pathway that leads to systemic granulomatous inflammation. Although presentations of sarcoidosis vary enormously, multi-organ involvement is a common feature. Cutaneous involvement occurs in about 25% of patients with protean manifestations and variable prognoses. Skin manifestations are divided into specific lesions with histopathologically evident non-caseating granulomas and nonspecific lesions arising from a reactive process that does not form granulomas. A peculiar form of cutaneous sarcoidosis is represented by sarcoidal lesions at sites of trauma that has caused scarring. The pathogenesis of scar sarcoidosis remains unknown. Scar sarcoidosis is also associated with herpes zoster infection, surgery, and tattooing. Such heterogeneous events, along with those at the sites of chronic lymphedema, thermal burns, radiation dermatitis, and vaccinations, occur on areas of vulnerable skin labeled "immunocompromised districts". Numerous options are available for the treatment of cutaneous sarcoidosis. Although corticosteroids remain the treatment of choice for initial systemic therapy, other nonsteroidal agents have proven effective and therefore useful for long-term management. Tumor necrosis factor-α antagonists such as infliximab may have a role in the treatment of cutaneous sarcoidosis, especially in refractory cases that are resistant to standard regimens. Elucidation of the relationship of sarcoidal granulomas with malignancy and immunity may facilitate a better understanding of some pathomechanisms operating in neoplastic and immunity-related disorders.

Sarcoidosis following Mycobacterium tuberculosis infection: Coincidence or consequence

We describe the case of a 47-year-old Caucasian male patient who developed sarcoidosis 18 months after he was diagnosed with pulmonary tuberculosis for which he was treated according to guidelines. The presentation of sarcoidosis was very similar to his first presentation when he was diagnosed with tuberculosis. Mycobacterium tuberculosis as a possible aetiological agent in sarcoidosis has been point of debate since many years and has been studied thoroughly. Recent advances in immunologic and molecular techniques have strengthened the association between mycobacteria and sarcoidosis.(1) Sarcoidosis is a systemic inflammatory disorder of unknown aetiology, characterised by the presence of non-caseating epitheloid cell granulomas. It is generally agreed that this is a tissue reaction to environmental agents in a genetically susceptible individual.(2) Tuberculosis is an infectious disease caused by M. tuberculosis and characterised by caseating granulomas. In both clinical and histopathological features sarcoidosis is remarkably similar to tuberculosis and therefore can be difficult to distinguish. First, this case report demonstrates the need of diagnostic testing when reactivation of tuberculosis is suspected. And second the role of M. tuberculosis in the aetiology of sarcoidosis will be discussed.

Sarcoidosis: a comprehensive review and update for the dermatologist: part I. Cutaneous disease

Sarcoidosis is a common systemic, noncaseating granulomatous disease of unknown etiology. The development of sarcoidosis has been associated with a number of environmental factors and genes. Cutaneous sarcoidosis, the "great imitator," can baffle clinicians because of its diverse manifestations and its ability to resemble both common and rare cutaneous diseases. Depending on the type, location, and distribution of the lesions, treatment can prevent functional impairment, symptomatic distress, scarring, and disfigurement. Numerous therapeutic options are available for the treatment of cutaneous sarcoidosis, but there are few well designed trials to guide practitioners on evidence-based, best practice management. In part I, we review the current knowledge and advances in the epidemiology, etiology, pathogenesis, and genetics of sarcoidosis, discuss the heterogeneous manifestations of cutaneous sarcoidosis, and provide a guide for treatment of cutaneous sarcoidosis.

Evidence for mycobacteria in sarcoidosis

Despite its recognition as a distinct granulomatous disease for over a century, the etiology of sarcoidosis remains to be defined. Since the early 1900s, infectious agents have been suspected in causing sarcoidosis. For much of this time, mycobacteria were considered a likely culprit, yet until recently, the supporting evidence has been tenuous at best. In this review, we evaluate the reported association between mycobacteria and sarcoidosis. Historically, mycobacterial infection has been investigated using histologic stains, cultures of lesional tissue or blood, and identification of bacterial nucleic acids or bacterial antigens. More recently, advances in biochemical, molecular, and immunological methods have produced a more rigorous analysis of the antigenic drivers of sarcoidosis. The result of these efforts indicates that mycobacterial products likely play a role in at least a subset of sarcoidosis cases. This information, coupled with a better understanding of genetic susceptibility to this complex disease, has therapeutic implications.

Toll-like receptor (TLR)-9 genetics and function in sarcoidosis

Sarcoidosis is a systemic disorder characterized by the formation of non-caseating granulomas in variable organs. Toll-like receptor (TLR)-9 is important in the innate immune response against both Mycobacterium tuberculosis and Propionibacterium acnes, candidate causative agents in sarcoidosis. The aim of our study was to investigate possible genetic and functional differences in TLR-9 between patients and controls. TLR-9 single nucleotide polymorphisms were genotyped in 533 patients and divided into a study cohort and validation cohort and 185 healthy controls. Furthermore, part of the promotor as well as the entire coding region of the TLR-9 gene were sequenced in 20 patients in order to detect new mutations. No genetic differences were found between patients and controls. In order to test TLR-9 function, peripheral blood mononuclear cells (PBMCs) of 12 healthy controls and 12 sarcoidosis patients were stimulated with a TLR-9 agonist and the induction of interleukin (IL)-6, interferon (IFN)-γ and IL-23 was measured. Sarcoidosis patients produce significantly less IFN-γ upon stimulation with different stimuli. Regarding IL-23 production, a significant difference between patients and controls was found only after stimulation with the TLR-9 agonist. In conclusion, we did not find genetic differences in the TLR-9 gene between sarcoidosis patients and controls. Sarcoidosis patients produce less IFN-γ regardless of the stimulating agent, probably reflecting the anergic state often seen in their peripheral blood T lymphocytes. The differences in TLR-9-induced IL-23 production could indicate that functional defects in the TLR-9 pathway of sarcoidosis patients play a role in disease susceptibility or evolution.

High prevalence of 'Borrelia-like' organisms in skin biopsies of sarcoidosis patients from Western Austria

BACKGROUND

Sarcoidosis is a multisystem granulomatous disorder of unknown aetiology with frequent skin involvement.

OBJECTIVE

To investigate the frequency of 'Borrelia-like' organisms in cutaneous sarcoidosis (CS) by focus-floating microscopy (FFM).

METHODS

Retrospective analysis of 38 CS specimens by immunohistochemistry with polyclonal anti-Borrelia antibody and assessment by FFM.

RESULTS

Specimens of 34.2% CS were positive for 'Borrelia-like' organisms by FFM. Usually single spirochetes, rarely pairs or small clusters of bacteria were observed between collagen bundles or at the periphery of granulomas. Polymerase chain reaction (PCR) was performed in addition in 11 cases and was negative in all biopsies. Samples of erythema migrans served as positive controls: 92.3% of 39 samples were positive by FFM, but only 46.6% gave positive results by PCR. Of 61 negative controls only one specimen was falsely positive by immunohistochemistry.

CONCLUSION

Detection of 'Borrelia-like' organisms by FFM in tissue sections of CS underlines the possibility that such microorganism maybe involved in the pathogenesis of some cases of CS.

Cutaneous sarcoidosis: updates in the pathogenesis

Sarcoidosis is a multiorgan granulomatous disease in which the skin is one of the frequently involved target organs. Cutaneous involvement occurs in a third of patients with sarcoidosis and has protean manifestations. More than a century has passed since the initial description of sarcoidosis, but its cause continues to be an enigma. Recent studies have introduced several new insights into the pathogenesis of this disease. The aim of this literature review was to provide a comprehensive overview on the current updates in the pathogenesis of sarcoidosis. This review has revealed that several genetic polymorphisms are associated with an increased risk of developing sarcoidosis, suggesting that genetic susceptibility to sarcoidosis is probably polygenic. Environmental factors may also modify the susceptibility to sarcoidosis. Evidence favouring an infectious aetiology has been accumulating, but the results of studies are conflicting. The current concept is that the pathogenesis of sarcoidosis involves a T-helper-1-mediated immune response to environmental antigens in a genetically susceptible host. The studies carried out on sarcoidosis have largely focused on the pulmonary aspects and have been mainly conducted by respiratory physicians. In contrast, research conducted on the cutaneous aspects of sarcoidosis is comparatively limited. Although tremendous advances have been made, there is a significant gap between the vast knowledge accumulated on sarcoidosis in recent years and the understanding of this disease.

Estimation of the spread of pathogenic mycobacteria in organic broiler farms by the polymerase chain reaction

Organic poultry breeding allows for increased exposure of birds to soil, faeces, and wildlife, which have been associated with the transmission of mycobacterial infections. Therefore the aim of this study was to investigate the spread of the major pathogenic mycobacteria in organically reared broilers in Greece using a diagnostic algorithm that relied on a combination of the polymerase chain reaction (PCR) and the restriction fragment length polymorphism analysis (RFLP). Liver, spleen and gonads from 81 to 150 days old broilers were aseptically collected post-mortem. 500 broilers from a population of 35,370, reared in the 25 registered as organic farms in Greece for the 2005 were used. DNA was isolated and incorporated to PCR targeted to 16S-rRNA gene (for Mycobacterium spp.), IS6110 (for Mycobacterium tuberculosis complex-MTBc), IS1245 (for Mycobacterium avium complex-MAC), IS901 (for M. avium subsp. avium-MAA) and hsp65 (for Mycobacterium genavense, by PCR-RFLP). The mean prevalence of mycobacteria detected by PCR with a 95% confidence interval was estimated to 4.4-8.8%. The relevant percentage with regard to the mycobacterial species that were included in this study was 0.17-2.03% for MAC, 2.11-3.39% for MTBc and 0.66-3.08% for mycobacteria not belonging to any of the above groups. None of the mycobacteria detected were identified as MAA or M. genavense. Considering that avian tuberculosis has been eradicated from conventional farms, the level and the pattern of positivity recorded here, indicates that our results may be associated with the specific conditions that apply to organic breeding.

Inflammatory pseudotumor associated with Mycobacterium tuberculosis infection

BACKGROUND

Inflammatory pseudotumor is a relatively rare entity; originally identified in the lung, it has been described in multiple extrapulmonary anatomic locations.

CASE REPORT

We report on the unusual case of an inflammatory pseudotumor associated with Mycobacterium tuberculosis infection, which was initially mistaken for a renal malignancy both in clinical and radiological settings. We additionally present three brief reviews concerning: (1) infectious agents postulated to induce morphological changes of an inflammatory pseudotumor; (2) mycobacterial pseudotumors; and (3) distinction from inflammatory myofibroblastic tumors of the renal pelvis.

CONCLUSIONS

The present case highlights the diagnostic importance of PCR-based detection of mycobacterial DNA in granulomatous tissue responses. It is of crucial importance that clinicians are aware of this unusual manifestation of mycobacterial infection to ensure that pertinent laboratory evaluation is employed and appropriate treatment is administered in order to avoid potential clinical implications.

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.

Considering an infectious etiology of sarcoidosis

Sarcoidosis is a systemic granulomatous disease of unknown cause. An infectious etiology of sarcoidosis has long been suspected, but only recently has scientific evidence provided a strong link between infectious agents and sarcoidosis. Moreover, recent advances in our understanding of the relationships between sarcoidosis phenotype and host genetic factors may further illuminate the mechanisms linking infection and sarcoidosis.

Comparative evaluation of positive tests to Mycobacterium avium subsp. paratuberculosis in clinically healthy sheep and goats in South-West Greece using molecular techniques, serology, and culture

Mycobacterium avium subsp. paratuberculosis (MAP) is the cause of paratuberculosis, which affects mainly ruminants although there is a growing concern about its possible implication in Crohn's disease in humans especially in connection with environmental spread and risks to the food chain. Retail cheese may represent a significant source of human exposure to MAP and the aim of this study was to assess MAP status in clinically healthy sheep and goats in Greece, comparing techniques routinely used in the positive diagnosis of the disease. From a total of 30 flocks, 632 sheep and goats had faecal, serum, and whole-blood samples examined by culture, complement fixation test (CFT), and polymerase chain reaction (PCR) targeted at IS900, IS1245, and IS6110. PCR produced positive results in 21% of the animals tested, with 5.6%, 3.9%, and 11.5% being identified as MAP, Mycobacterium avium subsp. avium, and Mycobacterium tuberculosis complex, respectively. CFT produced positive and suspicious results in 4.4% and 14.4% of the cases. Faecal cultures were negative in all but a single case that was identified as restriction fragment length polymorphism (RFLP)-type BC1. Agreement between results obtained by PCR and CFT was poor with isolated cases although an assessment of the MAP positive tests produced similar results for both methods. The findings indicate the need for additional measures of control, although the costs may be substantial if public health protection justifies elimination of MAP from livestock.

[Non-tuberculous systemic granulomatosis mimicking sarcoidosis but related to a specific etiology. Study of 67 cases]

PURPOSE

Systemic granulomatosis (SG) are frequently encountered in internal medicine. Despite a large list of aetiologies, the investigations remain often negative leading to the diagnosis of atypical sarcoidosis. The spectrum of the causes, as well as evolution of these SG is not clearly delineated in the literature.

METHOD

We analyzed the case reports of all but tuberculous GS submitted at the National Meetings of the National French Society of Internal Medicine from 1990 to 2006.

RESULTS

Sixty-seven cases were included in the study. The average age at the beginning of the symptoms was 47.8 years and 28.4% of the patients were female. The median diagnostic delay was one year. General symptoms were present in 73.1% of the cases. The involved organs were the liver (46.3%), lungs (25.4%), lymph nodes (22.4%), digestive tract (16.4%), skin (16.4%), spleen (14.9%). The granuloma were detected mainly in the liver (38.8%), lymph nodes (17.9%), bone marrow (16.4%) and lungs (11.9%). Elevated erythrocyte sedimentation rate or increased C reactive protein serum levels were noted in 65.6% of the patients. Before diagnosis, 19.4% of the patients received a corticotherapy. The most common diagnoses were infections (65.6%) followed by drugs (19.5%), "toxic substances" or various foreign bodies (5.9%), neoplasias (5.9%) and immune deficiencies (3%). The evolution was favourable in 80% of the cases but 8.3% of the patients died. The disease course of the patients having received a corticotherapy prior to the diagnosis was more unfavourable with a death rate of 45%.

CONCLUSION

In atypical sarcoidosis (fever, advanced age, increased acute phase reactants...) a specific aetiology and especially an infectious disease should be ruled out before considering the diagnosis of sarcoidosis. Corticotherapy is a factor of poor prognosis.

Linkage between Toll-like receptor (TLR) 2 promotor and intron polymorphisms: functional effects and relevance to sarcoidosis

The intracellular pathogens Propionibacterium acnes and Mycobacterium tuberculosis have been leading suspects as the cause of sarcoidosis, a systemic disorder characterized by the formation of non-caseating granulomas. Toll-like receptor (TLR) 2 is important in the innate immune response against both pathogens, and is therefore of interest in sarcoidosis research. In the present study, three single nucleotide polymorphisms and one dinucleotide repeat polymorphism in the TLR-2 gene were genotyped in 419 sarcoidosis patients, divided into a study cohort and a validation cohort, and 196 healthy controls. In the study cohort we found a significant increase in prevalence of the AA-genotype at promotor location -16934 in patients with chronic disease compared to patients with acute/self-remitting sarcoidosis (34.5% versus 15.9%, respectively, P = 0.006, P(c) = 0.019). These results could not be confirmed in our validation cohort, implicating a possible role for TLR-2 genetics in only a small percentage of sarcoidosis patients. Furthermore, linkage was found between the promotor polymorphism -16934 A/T and the number of GT repeats in intron 1 (P < 0.0001). After in vitro stimulation of peripheral blood mononuclear cells (PMBCs) with different TLR-2 agonists, a correlation between induction of TNF-alpha (P = 0.008), interleukin (IL)-12 (P = 0.008) as well as IL-6 (P = 0.02), and the number of GT repeats was observed. In conclusion, the data show that polymorphisms in TLR-2 might be important in a small group of sarcoidosis patients and that their functional consequences explain partly some of the variance in cytokine pattern observed in different clinical phenotypes of this disease.

Cutaneous sarcoidosis: the "great imitator": etiopathogenesis, morphology, differential diagnosis, and clinical management

Sarcoidosis is a multisystem disease that can involve almost any organ system. The underlying cause of the disease remains unknown. Immunopathologically and histologically, cutaneous sarcoidosis is characterized by a macrophage/T helper-1 cell-mediated, non-caseating, granulomatous inflammation process. An imbalance between proinflammatory and anti-inflammatory cytokines plays an important role in the development of cutaneous granulomas. Recognition of cutaneous sarcoidosis lesions is very important because they provide a visible clue to the diagnosis and are an easily accessible source of tissue for histologic examination. Because skin lesions of patients with the disease can exhibit many different morphologies, cutaneous sarcoidosis is known as one of the "great imitators" in dermatology. Specific manifestations can include patches (sometimes hypopigmented), papules, scar sarcoidosis, ulcers, ichthyosis, and alopecia. The treatment of cutaneous sarcoidosis is often frustrating because some of the skin lesions may be refractory to treatment or may recur following successful treatment. Systemic and topical corticosteroids are the most effective treatments for cutaneous sarcoidosis. This article focuses on the dermatologic aspects of sarcoidosis and includes a review of the most recent literature, which includes new data on the diagnosis, differential diagnosis, pathogenesis, and treatment of the disease.

Mycobacterial antigens may be important in sarcoidosis pathogenesis

PURPOSE OF REVIEW

To describe the most recent epidemiologic, molecular and immunologic literature related to the role of infectious antigens in sarcoidosis pathogenesis, with a focus upon Mycobacterium and Proprionibacterium species.

RECENT FINDINGS

Recent studies of successful molecular analysis for and humoral immunity to mycobacterial antigens from sarcoidosis patients have renewed interest in a potential role of mycobacteria in sarcoidosis. One study provided molecular and immunologic evidence for mycobacteria among sarcoidosis subjects from the United States. These studies, while preliminary, provide the groundwork for more in-depth studies of the potential role of mycobacteria in sarcoidosis pathogenesis. Proprionibacteria have also been proposed as a cause of sarcoidosis; a study of the detection of Proprionibacterium species nucleic acids throughout the lung of sarcoidosis and control subjects, however, suggests that these organisms are less likely to be causal.

SUMMARY

While the studies to date do not fulfill Koch's postulates, they do add further support to the hypothesis that infectious antigens, particularly those from mycobacteria, may have a causal role in some sarcoidosis cases. In future studies that purport to show an association of microbial antigen(s) with sarcoidosis, investigation of genetic risk factors contributing to risk will be important, in order to explain why some patients are found to have an association with microbial antigens and others are not.

Mycobacterium marinum, a further infectious agent associated with sarcoidosis: the polyetiology hypothesis

A 39-y-old male had a diagnosis of sarcoidosis and corticosteroid therapy was started. Surprisingly, following his discharge from hospital, Mycobacterium marinum was isolated in 1 of 3 sputum samples taken 7 weeks earlier on admission. After this, Mycobacterium marinum-DNA was identified in the stored lung biopsies by the PCR-RFLP of the hsp65 gene.

Characterization of Mycobacterium tuberculosis complex isolates from Greek patients with sarcoidosis by Spoligotyping

Spoligotyping was undertaken with 38 Mycobacterium tuberculosis isolates from Greek sarcoidosis patients and 31 isolates from patients with tuberculosis. Fifty percent of the isolates from sarcoidosis patients and 16.13% of the isolates from patients with tuberculosis were represented by a unique pattern, whereas the remaining isolates belonged to seven shared types. Interestingly, half of the isolates from sarcoidosis patients did not resemble the spoligotypes of the isolates from patients with tuberculosis, most of which pertained to shared spoligotypes.

Outbreak of Avian Mycobacteriosis in a Flock of Two-Year-Old Domestic Pigeons (Columba livia f. domestica)

This report describes an outbreak of avian mycobacteriosis in a flock of 100 two-yr-old pigeons. Over a 6-mo period, the sick pigeons showed cachexia followed by death. In Columbiformes classic tubercles rarely develop, but in these affected pigeons granulomatous nodular lesions of various sizes, containing numerous acid-fast bacilli, were found in the internal organs. The lesions were observed in the liver, spleen, intestine, bone marrow, ovary, and oviduct. Despite their breeding age, atrophy was also found in the ovary and oviduct. Microorganisms belonging to Mycobacterium avium complex were identified in the affected tissues by polymerase chain reaction.

Kaposi's sarcoma-associated herpesvirus: clinical, diagnostic, and epidemiological aspects

Kaposi's sarcoma-associated herpesvirus (KSHI) is one of the few viruses proven to be associated with tumorigenesis in humans. Its causal association with all clinical and epidemiological variants of Kaposi's sarcoma (KS) is well established. KSHV is also involved in the pathogenesis of primary effusion lymphoma (PEL) and a subset of multicentric Castleman's disease (MCD). Possible associations of KSHV with other clinical settings have been extensively examined. The findings from several of these studies are contradictory and are yet to be resolved. Concentrated effort over the last decade, since the initial discovery of KSHV, led to the development of several experimental systems that resulted in a better comprehension of the biological characteristics of KSHV and set the stage for the understanding of mechainisms by which diseases are induced by the virus. The development of molecular, histological, and serological tools for KSHV diagnosis allowed researchers to track the transmission and to study the epidemiology of KSHV. These assays have been applied, in particular in ambiguous cases, in order to confirm clinically and pathologically based diagnoses. Here, we review the advances in the clinical, experimental, diagnostic, and epidemiological research of KSHV.

High prevalence of Mycobacterium tuberculosis DNA in biopsies from sarcoidosis patients from Catalonia, Spain

BACKGROUND

Sarcoidosis is a systemic granulomatous disease of unknown etiology. The presence of mycobacterial nucleic acid components in patients with sarcoidosis has been demonstrated with varying degrees of success.

OBJECTIVES

The aim of this study was to estimate the presence of Mycobacterium tuberculosis DNA in tissues from sarcoidosis patients, in Catalonia, Spain, as well as to assess the long-term clinical course in these patients.

METHODS

Fifty-eight paraffin-embedded tissue biopsies corresponding to cases of sarcoidosis (n = 23), lung neoplasm (n = 23), and lung tuberculosis (n = 12) available in 1996 were analyzed in a retrospective study by means of a nested polymerase chain reaction using primers corresponding to the insertion element IS6110 of M. tuberculosis complex. For greater sensitivity, Southern blot hybridization was performed. Clinical data were recorded prior to and after PCR analysis (follow-up reported until 2002).

RESULTS

M. tuberculosis DNA was present in 9 out of 23 sarcoidosis biopsies (39%), in 1 out of 23 control patients (4%) (p < 0.01), and in all tissue samples from the 12 control patients with tuberculosis. To date, none of these sarcoidosis patients has developed tuberculosis over a mean (+/-SD) follow-up period of 11 (+/-3.4) years.

CONCLUSION

In our setting, M. tuberculosis DNA is present in tissue biopsies of significantly more sarcoidosis patients than controls. However, these results do not demonstrate causality, although they may suggest a link between M. tuberculosis infection and sarcoidosis in some cases. Follow-up of these patients suggests that M. tuberculosis-DNA-positive sarcoidosis patients are not at greater risk of developing tuberculosis than M. tuberculosis-DNA-negative patients.

Pulmonary sarcoidosis

Sarcoidosis is a multisystemic disease of unknown aetiology characterized by the formation of immune granulomas in involved organs. It is a worldwide disease that mainly affects 25-40 years old people with a lifetime incidence rate of 0.85-2.4%. Multiple clinical phenotypes are observed according to presentation, involved organs, disease duration and severity. Sarcoidosis primarily affects the lungs and the lymphatic system. The prevailing pathogenic hypothesis is that various antigens could promote sarcoidosis in genetically susceptible hosts, both these factors modulating the incidence and the clinical phenotype of sarcoidosis. So far, environmental agents have been suspected, including possible mycobacteria and propionibacteria. Interferon-gamma, tumour necrosis factor (TNF)-alpha, interleukin (IL)-12 and IL-18 play a critical role in driving the Th1 commitment in the course of granulomatous process. Evolution of sarcoidosis is often marked by spontaneous resolution within 12-36 months, but can be severe because of chronic cases with pulmonary fibrosis or involving other organs, including heart, central nervous system and eyes. Mortality, ranging between 0.5 and 5%, is most often related to pulmonary fibrosis. Corticosteroids can reverse the granulomatous process, but are only suspensive, and their long-term benefit remains under question. Corticosteroids are recommended when sarcoidosis shows unfavourable clinical tolerance and evolution. Alternative and corticosteroid-sparing therapies are of increased interest in difficult cases, while targeted new drugs such as anti-TNF-alpha are still under investigation.

Das Heerfordt-Syndrom ? eine seltene Erstmanifestation der Sarkoidose

Sarcoidosis is a chronic, multisystem disorder of unknown cause characterized by noncaseating epithelioid granulomas. Infectious agents and genetic components have been discussed. Heerfordt's syndrome with uveitis, enlargement of the parotid glands and optional paralysis of the Nn. facialis is a form of sarcoidosis. The diagnosis is confirmed by histology. Further analyses are fiberoptic bronchoscopy with bronchoalveolar lavage or the gallium-67 scan in combination with blood findings. The therapy of choice is glucocorticoids. We present a case report of Heerfordt's syndrome and a review of the literature covering different aspects of sarcoidosis.

Is there a role for microorganisms in the pathogenesis of sarcoidosis?

Sarcoidosis is a granulomatous disease that has the immunopathological features of being antigen-driven. It is a complex disease that appears to arise from the interaction of one or more triggers with an immunologically predisposed host. Previous reports of familial clustering and varying prevalence of sarcoidosis in different populations could reflect differences in ethnic predisposition or differences in local environmental exposures. This review focuses specifically on these areas that have been the subjects of intensive investigation recently. Specific focus is provided on the issue of an infective trigger and highlights popular candidates. It is concluded that microbes are a likely trigger (but not as an infection) in a genetically predisposed individual and that this initial event culminates in the sarcoidosis granulomatous response.