Sarcoidosis and the rheumatologist

Imaging mimickers of MSK infection

Along with clinical and laboratory findings, imaging has a significant role in the initial evaluation and treatment follow-up of a wide variety of infectious and non-infectious musculoskeletal (MSK) conditions. The imaging findings of many non-infectious MSK processes, such as inflammatory, metabolic, and degenerative arthropathies, complications of diabetes mellitus, osseous and soft tissue injuries, osteonecrosis, tumors, and tumor-like lesions may be nonspecific and often overlap with those found in MSK infections. In this article, the authors discuss the imaging findings of both frequent and rare mimickers of MSK infections, including potential distinguishing characteristics.

Perspective of sarcoidosis in terms of rheumatology: a single-center rheumatology clinic experience

Sarcoidosis may present with many rheumatological symptoms as well as mimic and/or may occur concomitantly with many other rheumatic diseases. We examined the demographic, clinical and laboratory characteristics of patients diagnosed with sarcoidosis in the rheumatology department. This study planned as retrospective cross-sectional study. Medical records of patients who applied to our rheumatology outpatient clinic due to complain of musculoskeletal problems and then diagnosed sarcoidosis were retrospectively investigated. Joint findings, extrapulmonary involvements, and coexisting rheumatic disease were evaluated. Fifty-six patients (41.21 ± 7.83 years, 75% female) were included. The duration of the disease was 49.61 ± 29.11 months, and the follow-up period was 26.66 ± 13.26 months. All patients had pulmonary system involvement. Arthralgia was present in 91.10% of 56 patients and arthritis in 89.29% of patients. Examining the subtypes of the arthritis findings, mono-arthritis was found in 31/50 (62%) patients, oligo-arthritis in 15/50 (30%) patients, and polyarthritis in 4/50 (8%) patients. A total of 11 (19.60%) patients were diagnosed with uveitis. Excision of the mediastinal LAP was performed in a total of 37 patients (66.1%) and became the most commonly employed method. Considering the treatment distribution of the patients under followed-up, it is seen that non-steroidal anti-inflammatory treatments were used in 15 (26.8%) patients, corticosteroids in a total of 40 (71.4%) patients, methotrexate in a total of 15 patients (26.8%), azathioprine in six (10.7%) patients, hydroxychloroquine in 14 (25%) patients, and infliximab in one (1.8%) patient. As sarcoidosis is a mimicking disease, a good differential diagnosis should be made to avoid misdiagnosis and in order not to be late in diagnosis and treatment. Physicians, especially rheumatologists, should remember sarcoidosis more frequently as the disease may overlap with other rheumatological diseases and may occur with many rheumatological manifestations.

Sarcoidosis beyond pulmonary involvement: A case series of unusual presentations

Unusual presentations of sarcoidosis pose a diagnostic challenge and warrant attention. Hematologic associations: Case 1 (37-years-old male): Pancytopenia: myelofibrosis (leading to sepsis and mortality) following a two-year quiescent course of biopsy-proven-sarcoidosis. Case 2: (38-years-old male): Presentation with thrombocytopenia (5 × 10³/cmm): immune thrombocytopenic purpura (histologically associated with megakaryocytic emperipolesis). Biopsied enlarged lymph nodes demonstrated sarcoidosis. Hematologic sarcoid involvement is usually due to granulomatous bone marrow (3.9%) or splenic infiltration (6–30%); however, the presented manifestations are scarcely reported with a potential significance that is yet to be elucidated. Case 3: Neurologic presentation: 48-years-old female: presentation with bilateral sensorineural hearing loss and facial palsy. Brain magnetic resonance imaging showed leptomeningeal thickening. Biopsied enlarged lymph nodes showed sarcoidosis. Case 4: Neurologic and renal manifestations: 13-years-old male (family history of sarcoidosis): Presenting with acute headache, investigations showed elevated serum creatinine (2.1 mg/dL) and angiotensin converting enzyme, and computed tomography chest and abdominal findings characteristic of sarcoidosis. Associated benign increased intracranial and acute tubulointerstitial nephritis (with eosinophils) were diagnosed upon concordant workup. Of sarcoidosis neurologic affection (5–10%), cranial nerve(s) involvement is among the most common (25–50% of neurosarcoid affection), particularly that of the facial nerve (Case 3). Leptomeningeal enhancement is among the most common neurosarcoid radiologic findings (30–40%). Whereas benign increased intracranial tension (Case 4) is much less reported. Among sarcoidosis renal involvement (35–50%), interstitial nephritis usually presents with granulomatous renal lesions, yet its sole association with sarcoidosis is unusual (Case 4). The portrayed atypical hematologic, neurologic, and renal manifestations further emphasize the masquerading nature of sarcoidosis.

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Although hematologic involvement in sarcoidosis is usually due to granulomatous infiltration of the bone marrow or spleen and/or hypersplenism, associations with hematologic neoplasms or myelodysplastic syndromes have been reported. However, coexisting myelofibrosis (presented in our first patient) is much less reported and raises interest.

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We present a patient with coexistent with ITP (case 2) that was further histologically associated with megakaryocytic emperipolesis. The significance of this association is yet to be elucidated.

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Cranial nerve(s) involvement is among the most widely neurosarcoid manifestations reported which was demonstrated in our third patient. Brain MRI showing evidence of leptomeningeal enhancement which is among the most common radiologic findings of neurosarcoidosis.

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A juvenile-onset patient with a family history of sarcoidosis manifested with benign increased intracranial tension (ICT) and renal affection in the form of tubulointerstitial nephritis. Unlike cranial nerve affection, benign ICT is a rarely reported neurosarcoid manifestation, and renal involvement is usually due to hypercalcemia or granulomatous involvement with or without tubulointerstitial nephritis.

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Although unusual presentations warrant attention as the pose a diagnostic and therapeutic challenge, they should be prudently interpreted.

Musculoskeletal sarcoidosis: A single center experience over 15 years

BACKGROUND

Musculoskeletal (MSK) sarcoidosis presents with a variety of clinical phenotypes. Four subtypes of MSK sarcoidosis have been identified to date: Lofgren syndrome, chronic sarcoid arthritis, osseous sarcoidosis, sarcoid myopathy. Each subtype has been reported with varying incidence mainly due to lack of universal classification criteria.

METHODS

We performed a retrospective chart review of patients with MSK sarcoidosis at a single academic center between January 2000 and December 2014. Descriptive statistics were used to describe the proportion of patients with sarcoidosis who had the 4 MSK syndromes of interest, demographic characteristics and therapeutic agents used.

RESULTS

A cohort of 58 patients with MSK manifestations were identified among 1016 patients with sarcoidosis. Frequency of subtypes include: Lofgren syndrome 46.6%, osseous sarcoidosis 25.9%, chronic sarcoid arthritis 24.1% and sarcoid myopathy 6.9%. The cohort was predominantly female (43/58 patients, 74%) and Caucasian (48/58 patients, 82.8%). Mean age was 47.2 years. One patient had overlap of osseous sarcoidosis and chronic sarcoid arthritis, another patient initially had Lofgren syndrome and later developed chronic sarcoid arthritis. Sarcoid myopathy patients presented with myalgia more often than muscle weakness.

CONCLUSION

We identified a large cohort of MSK sarcoidosis and determined the prevalence of all 4 subtypes. In patients who do develop MSK manifestations of sarcoidosis, they are commonly a part of the initial presentation of sarcoidosis. There is an unmet need to establish standardized classification criteria for the 4 MSK sarcoidosis syndromes.

Sternoclavicular joint arthritis as the initial presentation of sarcoidosis

Sarcoidosis is a multisystem granulomatous disease of unknown etiology. It can affect the musculoskeletal system in the form of acute and rarely, in the form of chronic peripheral arthritis involving bilateral small and large joints. Axial joint involvement with sarcoidosis is rare. Herein we report a case with sternoclavicular joint arthritis as the initial presentation of sarcoidosis. This report aims to demonstrate a rare initial presentation of sarcoidosis and highlight the importance of considering sarcoidosis as a differential diagnosis in patients presenting with sternoclavicular joint arthritis.

Paroxysmal cough and left sacroiliac joint pain in a 50-year-old Caucasian man

A 50-year-old Caucasian man who was a lifelong nonsmoker presented with a 3-year history of paroxysmal dry cough, fatigue, nonspecific myalgias, muscle weakness of the lower extremities and left sacroiliac joint pain. Initially, he was reviewed by a pulmonologist and subsequently he was referred to the Dept of Thoracic Medicine (Heraklion University Hospital, Heraklion, Greece) for further investigation. His medical history was remarkable for the presence of arterial hypertension on treatment with amlodipine and irbesartan.

Can you diagnose this patient with pulmonary symptoms, thoracic and laboratory test abnormalities and sacroiliac joint pain?http://ow.ly/LPyy30kaViz

Concomitant Systemic Sclerosis and Sarcoidosis with Combined Pulmonary Fibrosis and Emphysema

A 75-year-old woman was referred to our hospital with the chief symptom of dyspnea. Chest computed tomography revealed lymphadenopathy, emphysema, and honeycombing. Sarcoidosis was diagnosed due to an elevated serum ACE level and the findings of a lymph-node biopsy. Her smoking history, radiography findings, and impaired gas exchange indicated combined pulmonary fibrosis and emphysema (CPFE). Raynaud's phenomenon gradually appeared, and we also diagnosed her with systemic sclerosis (SSc). Right heart catheterization revealed pulmonary hypertension (PH). Smoking was assumed to be the chief cause, but SSc may also induce the development of CPFE. Severe PH induced by CPFE or SSc was present, but the influence of sarcoidosis also could not be ignored.

Laparoscopic splenectomy for isolated splenic sarcoidosis

Isolated splenic sarcoidosis is a rare manifestation of extrapulmonary disease and may be amenable to minimally invasive surgical technique.

Introduction:

Sarcoidosis is an inflammatory disease with an unknown etiology. The pulmonary interstitium is mainly involved, with noncaseating granulomas and lymphadenopathy. It is a multisystemic disease, and the differential diagnosis should include infectious, neoplastic, and autoimmune diseases to prevent inappropriate treatment and unnecessary surgery. Abdominal disease without evidence of pulmonary abnormalities on chest radiography in sarcoidosis can be found in approximately 25% to 38% of cases.

The approach to isolated splenic nodules in a patient with nonspecific abdominal symptoms should be focused on exclusion of malignancies and infections, and may require computed tomography, magnetic resonance imaging, and positron emission tomography–computed tomography imaging; scintigraphy; bone marrow biopsy; breast and genital examinations; and endoscopies.

This report documents a rare case of isolated granulomatous disease of the spleen that was diagnosed and treated laparoscopically.

Case:

A 29-year-old woman presented with nonspecific complaints such as nausea, vomiting, and epigastric discomfort. Further laboratory test results were normal. Abdominal ultrasonography, computed tomography, and magnetic resonance imaging revealed multiple splenic lesions. Additional examination findings were negative for occult neoplasia or infectious disease. Laparoscopic splenectomy was performed as a diagnostic procedure, without complications, and the final diagnosis was sarcoidosis.

Conclusion:

Isolated splenic sarcoidosis is a rare manifestation of extrapulmonary disease. The final diagnosis may be achieved only by histology, requiring biopsy or splenectomy. Minimally invasive surgery is a safe and efficient method for diseases of the spleen and should be the first option when feasible. The patient did well; however, further monitoring is required to diagnose recurrence.

Prevalence and clinical picture of musculoskeletal sarcoidosis

Background:

Sarcoidosis is a multisystem disease affecting different organs with different frequency rates depending on geographical location. Musculoskeletal abnormalities includes osseous lesions (small and large bone sarcoidosis), sarcoidal arthropathy, and sarcoidal myopathy. Musculoskeletal involvement is reported in a significant number of patients.

Objectives:

This study aimed to determine the prevalence and clinical picture of musculoskeletal sarcoidosis in Iranian cohort of patients with sarcoidosis.

Patients and Methods:

We designed a descriptive cross-sectional study including 30 patients with sarcoidosis who had hospitalized in the Rheumatology Department at Ghaem Hospital, Mashhad, Iran. The patients were evaluated for musculoskeletal symptoms using history, physical examination, and paraclinical data.

Results:

Of the 30 studied patients, 24 were female (80%) and six were male (20%). The mean age at diagnosis was 38 years. Sarcoidal arthropathy (arthritis and periarthritis) was observed in 26 patients (86.6%). Furthermore, the initial presentation was associated with joint symptoms in 19 cases (63.3%); acute arthritis developed in 17 (65%) while bone and muscle involvements each occurred in 2 (6.6%).

Conclusions:

Sarcoidosis is a common disease in women aged 20 to 40 years. The most common involved joint were consecutively ankles, knees, and wrists, reaching a accumulated frequency of 86.6%; however, bone and muscle involvements were uncommon.

TDP-43 frontotemporal lobar degeneration and autoimmune disease

BACKGROUND

The aetiology and pathogenesis of non-genetic forms of frontotemporal dementia (FTD) is unknown and even with the genetic forms of FTD, pathogenesis remains elusive. Given the association between systemic inflammation and other neurodegenerative processes, links between autoimmunity and FTD need to be explored.

OBJECTIVE

To describe the prevalence of systemic autoimmune disease in semantic variant primary progressive aphasia (svPPA), a clinical cohort, and in progranulin (PGRN) mutation carriers compared with neurologically healthy normal controls (NC) and Alzheimer's disease (AD) as dementia controls.

DESIGN

Case control.

SETTING

Academic medical centres.

PARTICIPANTS

129 svPPA, 39 PGRN, 186 NC and 158 AD patients underwent chart review for autoimmune conditions. A large subset of svPPA, PGRN and NC cohorts underwent serum analysis for tumour necrosis factor α (TNF-α) levels.

OUTCOME MEASURES

χ(2) Comparison of autoimmune prevalence and follow-up logistic regression.

RESULTS

There was a significantly increased risk of autoimmune disorders clustered around inflammatory arthritides, cutaneous disorders and gastrointestinal conditions in the svPPA and PGRN cohorts. Elevated TNF-α levels were observed in svPPA and PGRN compared with NC.

CONCLUSIONS

svPPA and PGRN are associated with increased prevalence of specific and related autoimmune diseases compared with NC and AD. These findings suggest a unique pattern of systemic inflammation in svPPA and PGRN and open new research avenues for understanding and treating disorders associated with underlying transactive response DNA-binding protein 43 aggregation.

Sarcoidosis Presenting as Löfgren's Syndrome with Myopathy

A 34-year-old female patient, who had proximal muscle weakness for 8 months, presented with erythema nodosum lesions on the pretibial region in addition to pain, swelling, and movement restriction in both ankles for the last one month. Thoracic CT demonstrated hilar and mediastinal lymphadenopathy. She underwent mediastinoscopic lymph node biopsy; biopsy result was consistent with noncaseating granuloma. Serum angiotensin converting enzyme level and muscle enzymes have been elevated. Muscular MRI and EMG findings were consistent with myositis. Muscle biopsy was done, and myopathy was found. The patient was diagnosed with sarcoidosis, Löfgren's syndrome, and sarcoid myopathy. The patient displayed remarkable clinical and radiological regression after 6-month corticosteroid and MTX therapy.

Increased IL-17A expression in granulomas and in circulating memory T cells in sarcoidosis

OBJECTIVE

Sarcoidosis is a systemic inflammatory disorder characterized by granulomas. Although the aetiology is unknown, sarcoidosis is thought to be mediated by Th1 lymphocytes. Recently, IL-17A has been implicated in granuloma formation in various diseases, including tuberculosis. Therefore, we hypothesized that Th17 cells play a role in sarcoidosis, paralleling recent findings in autoimmune diseases such as RA. The aim of our study was to investigate the role of Th17 cells in sarcoidosis.

METHODS

T cells were investigated by intracellular flow cytometry and immunohistochemistry, in blood, bronchoalveolar lavages (BALs) and bronchial mucosal biopsies from a cohort of newly diagnosed sarcoidosis patients and healthy controls.

RESULTS

Circulating memory CD4(+) T-cell populations of sarcoidosis patients contained significantly increased proportions of IL-17A(+) cells when compared with healthy controls. Interestingly, proportions of IL-17A/IFN-γ and IL-17A/IL-4 double-producing cells were significantly increased in blood of sarcoidosis patients and were present in substantial numbers in BAL. In granuloma-containing, but not in non-granulomatous sarcoidosis biopsies, we found significantly increased numbers of IL-17A(+) T cells, located in and around granulomas throughout the lamina propria. IL-22(+) T cells were increased in the subepithelial layer.

CONCLUSIONS

Enhanced IL-17A expression in granulomas and the presence of IL-17A(+), IL-17A(+)IFN-γ(+) and IL-17A(+)IL-4(+)memory Th cells in the circulation and BAL indicate Th17 cell involvement in granuloma induction or maintenance in sarcoidosis. Therefore, neutralization of IL-17A activity may be a novel strategy to treat sarcoidosis.

Association of sarcoidosis and immune thrombocytopenia: presentation and outcome in a series of 20 patients

The association of sarcoidosis and immune thrombocytopenia (ITP) has rarely been investigated. The aim of the current retrospective study was to investigate the clinical and biological phenotypes and outcome of this association in a large series of recent patients. Twenty patients (50% men) were included. Median age at sarcoidosis and ITP diagnosis was 36 (range, 10-83 yr) and 38 (range, 21-83 yr) years, respectively. In 11 of 20 (55%) patients, sarcoidosis onset preceded ITP (median interval, 48 mo; range, 6-216 mo). In 5 of 20 (25%) patients, the 2 conditions occurred concomitantly. In 4 of 20 (20%) patients, ITP onset preceded sarcoidosis (median interval, 68 mo; range, 15-153 mo). In 4 cases, sarcoidosis and ITP were not concomitant, since 1 condition was cured before the other was declared. In 12 of 20 (60%) patients there was a simultaneous onset or relapse of both ITP and sarcoidosis. Sarcoidosis phenotype was characterized by an acute onset in 40% of patients. The visceral involvement included thoracic sites in 19 of 20 (95%) patients and extrathoracic sites in 16 of 20 (80%) patients. At ITP onset, median platelet count was 11 × 10/L (range, 3-90); 17 (85%) patients had a platelet count <30 × 10/L. Seven (35%) patients had a bleeding score >8 without visceral bleeding.Nineteen of the 20 (95%) patients were treated specifically for ITP. After the first-line therapy (prednisone at 1 mg/kg per day for at least 3 consecutive weeks in all patients; with IVIg in addition for 10 patients with severe bleeding score), 12 of 19 (63%) patients achieved a complete response, 6 (31.5%) had a partial response, and only 1 patient failed to respond. At the end of ITP follow-up (median, 70 mo; range, 12-142 mo), 18 (90%) patients achieved a complete response, 1 achieved a partial response, and 1 had no response. After a median follow-up of 105 months, 13 of 20 (65%) patients had persistent sarcoidosis requiring prolonged therapy, and thus sarcoidosis represented the main long-term concern. Main conclusions were 1) ITP presentation was usually severe, but response to treatment was favorable in almost all cases, with no death and no severe bleeding, in contrast with older reports, 2) sarcoidosis was remarkable for the high proportion of cases with an acute onset, a chronic course, and the need for prolonged prednisone therapy, 3) sarcoidosis and ITP onset and evolution were not always synchronous.

Disturbed homeostasis and multiple signaling defects in the peripheral blood B-cell compartment of patients with severe chronic sarcoidosis

The presence of hypergammaglobulinemia, autoantibodies, and circulating immune complexes suggests that humoral immunity may contribute to the pathogenesis of sarcoidosis. However, little is known about the role played by B cells in the development of this disease. Here we investigated the subpopulation distribution, response to stimulation, and levels of the nuclear transcription factor NF-κB/p65 in peripheral blood B cells from patients with severe chronic sarcoidosis. Patients with severe chronic sarcoidosis had absolute B-cell lymphopenia and exhibited significantly decreased frequencies and total numbers of memory (CD19(+) CD27(+)) B cells. The reduced numbers of memory B cells in these patients reflected a decrease in the total numbers of class-switched (CD19(+) CD27(+) IgD(-)) and unswitched (CD19(+) CD27(+) IgD(+)) memory B cells and coincided with an increased frequency of circulating (CD19(+/-) CD20(-) CD27(++)) plasmablasts. Polyclonal stimulation of sarcoid B cells resulted in reduced expression of activation markers (i.e., CD25, CD69, and CD86), decreased proliferation, and impaired plasma cell differentiation. Baseline expression of p65 in B cells was reduced in 65% of the patients. These results suggest disturbed homeostasis, intrinsic signaling defects, and anergy within the peripheral B-cell compartments of patients with severe chronic sarcoidosis.

The sarcoid-lymphoma syndrome

Whether a relationship exists between sarcoidosis and lymphoma is controversial. We present 4 patients diagnosed with sarcoidosis either during or after the treatment of lymphoma, review the data surrounding the entity known as "sarcoid-lymphoma syndrome" and discuss the diagnostic pitfalls it can present. As both entities are fluorine-18 fluorodeoxyglucose avid, histologic verification and clinical acumen are needed to avoid misdiagnosis before initiating therapy.

Rheumatologic manifestations of sarcoidosis

Sarcoidosis is a systemic, clinically heterogeneous disease characterized by the development of granulomas. Any organ system can be involved, and patients may present with any number of rheumatologic symptoms. There are no U.S. Food and Drug Administration-approved therapies for the treatment of sarcoidosis. Diagnosing sarcoidosis becomes challenging, particularly when its complications cause patients' symptoms to mimic other conditions, including polymyositis, Sjögren syndrome, or vasculitis. This review presents an overview of the etiology of and biomarkers associated with sarcoidosis. We then provide a detailed description of the rheumatologic manifestations of sarcoidosis and present a treatment algorithm based on current clinical evidence for patients with sarcoid arthritis. The discussion will focus on characteristic findings in patients with sarcoid arthritis, osseous involvement in sarcoidosis, and sarcoid myopathy. Arthritic conditions that sometimes coexist with sarcoidosis are described as well. We present two cases of sarcoidosis with rheumatologic manifestations. Our intent is to encourage a multidisciplinary, translational approach to meet the challenges and difficulties in understanding and treating sarcoidosis.

Lung sarcoidosis induced by TNF antagonists in rheumatoid arthritis: a case presentation and a literature review

We report on a 72 year-old woman with long-standing rheumatoid arthritis diagnosed as granulomatosis due to pulmonary sarcoidosis after 49 months of treatment with etanercept. A clinical and radiological improvement was seen after tumor necrosis factor (TNF) antagonist withdrawal plus a course of steroids. Currently, 27 cases of histological proven sarcoidosis with pulmonary involvement have been reported in relation to anti-TNF therapy, with etanercept being more frequent in comparison with the anti-TNF monoclonal antibodies infliximab and adalimumab. Potential pathogenic mechanisms of the paradoxical effect of anti-TNF treatment is discussed. It is important for clinicians to be aware of this potential and uncommon complication of biological therapy with TNF antagonists.

Primary musculoskeletal sarcoidosis

Sarcoidosis is a well-described clinical entity with several types of presentation among different organ systems. However, primary musculoskeletal manifestation is a rare and seldom-described manifestation. A retrospective review of patients seen at our institution from 1999 to 2009 was performed to identify patients with such presentation. Eleven patients with musculoskeletal sarcoidosis were identified. Seven patients presented with solitary lesions, while 4 presented with multiple foci of disease. Histologically, all lesions revealed granulomatous inflammation consistent with sarcoidosis. Cultures and gram stain were negative in all patients. One patient was found to have evidence of pulmonary sarcoidosis after diagnosis of musculoskeletal sarcoidosis. Eight patients had primarily soft tissue involvement with visible masses, while 3 patients had primarily osseous involvement with no mass. Pain was reported by 9 of 11 patients. On magnetic resonance imaging, all lesions were dark on T1, bright on T2, and poorly marginated. Magnetic resonance imaging was noted to be more accurate in revealing the pathology than radiographic imaging. Four patients underwent complete excision and 1 received a steroid injection. The remaining patients required no further treatment after diagnosis. Musculoskeletal sarcoidosis is rare and can present as single or multiple lesions. Definitive diagnosis is made by biopsy. The decision to operate should be based on symptoms, issues with cosmesis, impending fractures, growth, and/or involvement of neuro-vascular structures. Patients should be evaluated for pulmonary involvement.

Sarcoidosis in a patient with systemic sclerosis and primary biliary cirrhosis

A 73-year-old woman who had been diagnosed with systemic sclerosis was admitted for further examination of bilateral hilar lymphadenopathy. Sarcoidosis was confirmed based on elevated serum levels of angiotensin-converting enzyme, a high proportion of lymphocytes and a high CD4/CD8 ratio in bronchoalveolar lavage fluid, abnormal (67)Gallium uptake in the mediastinum and noncaseating granulomas in skin biopsy specimens. In addition, high levels of antimitochondrial M2 antibodies and alkaline phosphatase indicated primary biliary cirrhosis (PBC). Here we describe a rare triplex of sarcoidosis, SSc and PBC. Although the etiology of this complex remains unknown, these three diseases might share some pathogenesis.

[Young woman with relapsing arthritis]

A 28-years old lady complains of self-limited episodes of relapsing knee arthritis of 48-72h of duration every 2 weeks. Immunological profile was all negative. At the same time, radiological images did not reveal any abnormality. She underwent to knee arthroscopy, however, a definite diagnosis was not reached. We discuss the differential diagnosis of relapsing arthritis.

Role of NADPH oxidase in formation and function of multinucleated giant cells

Macrophages play essential roles in a wide variety of physiological and pathological processes. One of the unique features of these phagocytic leukocytes is their ability to fuse, forming multinucleated giant cells. Multinucleated giant cells are important mediators of tissue remodeling and repair and are also responsible for removal or sequestration of foreign material, intracellular bacteria and non-phagocytosable pathogens, such as parasites and fungi. Depending on the tissue where fusion occurs and the inflammatory insult, multinucleated giant cells assume distinctly different phenotypes. Nevertheless, the ultimate outcome is the formation of large cells that can resorb bone tissue (osteoclasts) or foreign material and pathogens (giant cells) extracellularly. While progress has been made in recent years, the mechanisms and factors involved in macrophage fusion are still not fully understood. In addition to cytokines and a number of adhesion proteins and receptors, it is becoming increasingly clear that NADPH oxidase-generated reactive oxygen species (ROS) also play an important role in macrophage fusion. In this review, we provide an overview of macrophage multinucleation, with a specific focus on the role of NADPH oxidases and ROS in macrophage fusion and in the function of multinucleated giant cells. In addition, we provide an updated overview of the role of these cells in inflammation and various autoimmune diseases.