Sacroiliitis in sarcoidosis: case reports and review of the literature

Spondyloarthritis and sarcoidosis: Related or fake friends? A systematic literature review

BACKGROUND

Sarcoidosis and spondyloarthritis (SpA) have been regularly associated. Bone iliac granulomas have also been described. We propose herein a systematic review of rheumatologic axial manifestations of sarcoidosis.

METHODS

PubMed and the Cochrane Library were used to conduct this systematic literature review. Case reports and cross-sectional studies were reviewed according to Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

A total of 41 articles were eligible. Three cross-sectional studies on the association between SpA and sarcoidosis showed a prevalence of sacroiliitis and SpA ranging from 12.9 to 44.8% and 12.9 to 48.3% in inflammatory back pain (IBP) subgroups, respectively. However, the IBP definitions and sacroiliac joint (SIJ) imaging modalities (X-rays or magnetic resonance imaging) were heterogeneous, and X-ray was mainly used for sacroiliitis diagnosis (in 78% of cases). Thirty-one case-report articles of the sarcoidosis-sacroiliitis association were identified, representing 35 patients. ASAS criteria for SpA were met in half of cases (16/32) and 46% (12/26) had HLA B27 positivity. Sarcoidosis occurred after sacroiliac symptoms in 47% of cases. In the seven case-report articles with granulomatous sacroiliac bone involvement, unilateral involvement seemed higher than in the sarcoidosis-sacroiliitis group.

CONCLUSION

Literature analysis found a good evidence of the association between SpA and sarcoidosis, and special attention should be given to patients reporting IBP. Unilateral sacroiliitis may raise suspicion of granulomatous bone involvement, distinct from sacroiliitis. Imaging modalities used to study the SIJ in patients with sarcoidosis have been heterogeneous and further investigation is needed.

Osseous manifestations of sarcoidosis

Sarcoidosis is a systemic multisystem inflammatory disease of unknown etiology. The disease is characterized by formation of non-caseating granulomas. The most common presentation is bilateral hilar lymphadenopathy and lung infiltration, but the disease is very heterogeneous, with an unpredictable clinical course. Musculoskeletal manifestations are common. Bone involvement is less frequent, and usually occurs in patients with chronic multisystem course of the disease. They are most commonly found in the phalanges of hands and feet, and are usually bilateral. The skull, long bones, ribs, pelvis, and axial skeleton may also be affected. Osseous involvement may be asymptomatic but in some cases can cause a severe disability. Imaging techniques are important for diagnosis. Radiological investigations revealed sclerotic or destructive lesions (involving also joints), cystic and punched out lesions and cortical abnormalities. Biopsy is required for differential diagnosis with respect to malignancy. Treatment is a part of systemic therapy and is not needed in all cases. Glucocorticoids and TNF-α antagonists are used for management.

A review of the musculoskeletal manifestations of sarcoidosis

Sarcoidosis is a systemic disease of unknown aetiology that is characterized by granulomatous inflammation that can develop in almost any organ system. Musculoskeletal manifestations are seen in up to one-third of patients, ranging from arthralgia through to widespread destructive bone lesions. Inflammatory tendon lesions and periarticular swelling are more common than true joint synovitis. Despite advances in our understanding of the pathophysiology of the disease, diagnosis remains challenging. Definitive diagnosis, irrespective of organ site involvement, hinges on histological confirmation of non-caseating granuloma combined with an appropriate clinical syndrome. Musculoskeletal involvement usually develops early in the disease course. Imaging modalities, particularly fluorodeoxyglucose PET, are helpful in delineating the extent of involvement and measuring disease activity. Bone involvement may only become apparent following isotope imaging. Corticosteroids remain the cornerstone of treatment. MTX is the steroid-sparing agent of choice unless there is renal involvement. Biologic therapies are sometimes used in severe disease, although the evidence base for efficacy is inconsistent.

Sacroiliitis mimics: a case report and review of the literature

BACKGROUND

Radiographic sacroiliitis is the hallmark of ankylosing spondylitis (AS), and detection of acute sacroiliitis is pivotal for early diagnosis of AS. Although radiographic sacroiliitis is a distinguishing feature of AS, sacroiliitis can be seen in a variety of other disease entities.

CASE PRESENTATION

We present an interesting case of sacroiliitis in a patient with Paget disease; the patient presented with inflammatory back pain which was treated with bisphosphonate. This case demonstrates comorbidity with Paget disease and possible ankylosing spondylitis. We also present a review of the literature for other cases of Paget involvement of the sacroiliac joint.

CONCLUSIONS

In addition, we review radiographic changes to the sacroiliac joint in classical ankylosing spondylitis as well as other common diseases. We compare and contrast features of other diseases that mimic sacroiliitis on a pelvic radiograph including Paget disease, osteitis condensans ilii, diffuse idiopathic skeletal hyperostosis, infections and sarcoid sacroiliitis. There are some features in the pelvic radiographic findings which help distinguish among mimics, however, one must also rely heavily on extra-pelvic radiographic lesions. In addition to the clinical presentation, various nuances may incline a clinician to the correct diagnosis; rheumatologists should be familiar with the imaging differences among these diseases and classic spondylitis findings.

Classification and Diagnosis of Axial Spondyloarthritis — What Is the Clinically Relevant Difference?

Objective.

The Assessment of Spondyloarthritis international Society (ASAS) classification criteria for axial spondyloarthritis (axSpA) have added nonradiographic axSpA (nr-axSpA) to the classic ankylosing spondylitis (AS) as defined by the modified New York criteria. However, some confusion remains about differences between classification and diagnosis of axSpA. Our objective was to analyze differences between classification and diagnostic criteria by discussing each feature of the classification criteria based on real cases.

Methods.

The clinical features of the ASAS classification criteria were evaluated in relation to their significance for an expert diagnosis of axSpA. Twenty cases referred to our tertiary center outpatient clinic were selected because of an incorrect diagnosis of axSpA: 10 cases in which axSpA had been excluded initially because the classification criteria were not fulfilled, and 10 patients who had been previously diagnosed with axSpA because the classification criteria were fulfilled. Upon reevaluation, the former were diagnosed with axSpA while the latter had other diseases.

Results.

All items that are part of the classification criteria show some variability related to their relevance for a diagnosis of axSpA. There are clinical features suggestive of axSpA that are not part of the classification criteria. Misinterpretation of imaging procedures contributed to false-positive results. Rarely, other diseases may mimic axSpA.

Conclusion.

Because the sensitivity and specificity of the axSpA classification criteria have been around 80% in clinical trials, some false-positive and false-negative cases were expected. It is hoped that their detailed description and discussion will help to increase the understanding of diagnosing axSpA in relation to the ASAS classification criteria.

The prevalence of sacroiliitis and spondyloarthritis in patients with sarcoidosis

Introduction. Sarcoidosis is a chronic granulomatous disease, which can involve different organs and systems. Coexistence of sarcoidosis and spondyloarthritis has been reported in numerous case reports. Purpose. To determine the prevalence of sacroiliitis and spondyloarthritis in patients previously diagnosed with sarcoidosis and to investigate any possible relation with clinical findings. Materials and Methods. Forty-two patients with sarcoidosis were enrolled in the study. Any signs and symptoms in regard to spondyloarthritis (i.e., existence of inflammatory back pain, gluteal pain, uveitis, enthesitis, dactylitis, inflammatory bowel disease, and psoriasis) were questioned in detail and biochemical tests were evaluated. Sacroiliac joint imaging and lateral heel imaging were performed in all patients. Results. Sacroiliitis was found in 6 of the 42 (14.3%) sarcoidosis patients and all of these patients were female. Common features of the disease in these six patients were inflammatory back pain as the major clinical complaint, stage 2 sacroiliitis as revealed by radiological staging, and the negativity of HLA B-27 test. These six patients with sacroiliitis were diagnosed with spondyloarthritis according to the criteria of ASAS and of ESSG. Conclusion. We found spondyloarthritis in patients with sarcoidosis at a higher percentage rate than in the general population (1-1.9%). Controlled trials involving large series of patients are required for the confirmation of the data.

Coexistence of Ankylosing Spondylitis and Löfgren's Syndrome

A 46-year-old male patient diagnosed with ankylosing spondylitis presented to our polyclinic with complaints of pain, swelling, and limitation in joint mobility in both ankles and erythema nodosum skin lesions in both pretibial sites. The sacroiliac joint graphy and the MRI taken revealed active and chronic sacroiliitis. On the thorax CT, multiple mediastinal and hilar lymphadenopathies were reported. Mediastinoscopic excisional lymph node biopsy was taken and noncalcified granulomatous structures, lymphocytes, and histiocytes were determined on histopathological examination. The patients were diagnosed with ankylosing spondylitis, sarcoidosis, and Löfgren's syndrome. NSAIDs, sulfasalazine, and low dose corticosteroid were started. Significant regression was seen in the patient's subjective and laboratory assessments.

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.

An assessment of back pain and the prevalence of sacroiliitis in sarcoidosis

OBJECTIVES

Sarcoidosis is a chronic granulomatous multisystem disease in which arthritis is relatively common. Arthritis of the sacroiliac joints (sacroiliitis) has been described in sarcoidosis but is thought to be rare. The objective of this study was to determine the prevalence of sacroiliitis in a secondary-care population of patients with sarcoidosis.

METHODS

Patients attending a specialist secondary-care sarcoidosis clinic underwent evaluation of spinal symptoms using a standard back pain questionnaire, examination of spinal mobility, and laboratory measurements of erythrocyte sedimentation rate, C-reactive protein, serum angiotensin-converting enzyme, and neopterin/creatinine ratio. Tissue typing for the presence of the human leukocyte antigen (HLA)-B27 allele was undertaken. Radiographs of the sacroiliac joints were obtained in each patient and reviewed independently by two observers; a further observer reviewed disputed radiographs.

RESULTS

Sixty-one patients completed the assessments (80.3% of all patients invited to participate). Forty-nine of 61 patients (80.3%) reported having back pain at some point in their lives. Thirty-one of 61 patients (50.8%) had a score on the back pain questionnaire suggestive of inflammatory spinal disease, but only 3 of these patients had erosive damage of the sacroiliac joints on radiography indicating sacroiliitis. One further patient had erosive damage on radiography, making a total of four individuals with evidence of sacroiliitis, a prevalence of 6.6%. Four patients (one patient with sacroiliitis) were positive for HLA-B27. The back pain questionnaire had a sensitivity of 75% and a specificity of 51% for sacroiliitis in this population.

CONCLUSION

The prevalence of spondyloarthropathy in the normal population has been estimated to be 1.9%. In the sarcoid population studied the prevalence was 6.6% suggesting a possible association between these two conditions. The standard back pain questionnaire for the identification of inflammatory spinal disease had a low sensitivity and specificity in this population.