A large national cohort of French patients with chronic recurrent multifocal osteitis

Chronic Recurrent Multifocal Osteomyelitis and Related Diseases-Update on Pathogenesis

PURPOSE OF REVIEW

We focus on recent advances in the understanding of the genetic, molecular, immunologic, and environmental factors implicated in the pathogenesis of autoinflammatory bone diseases including the syndromic and non-syndromic forms of chronic recurrent multifocal osteomyelitis (CRMO).

RECENT FINDINGS

Evidence implicating the IL-1 pathway in the pathogenesis of the Mendelian forms of CRMO is growing. LIPIN2 can regulate the NLRP3 inflammasome by affecting P2X7 receptor activation, and intracellular cholesterol can modulate P2X7R currents. Work in a mouse model of CRMO demonstrates that dietary manipulation can alter the microbiome and protect these mice from the development of sterile osteomyelitis in vivo. Although the genetic and immunologic basis of non-syndromic CRMO remains only partially understood, the IL-1 pathway is central to the pathogenesis in the syndromic autoinflammatory bone disorders. Recent work implicates lipids and the microbiome in sterile osteomyelitis.

Physicians' Perspectives on the Diagnosis and Treatment of Chronic Nonbacterial Osteomyelitis

Background/Purpose. Understanding the practices of pediatric rheumatologists in diagnosing and treating chronic nonbacterial osteomyelitis (CNO) can provide important information to guide the development of consensus treatment plans. The objectives of this study were to determine physicians' approaches to (1) diagnosing and monitoring CNO, (2) ordering a bone biopsy, and (3) making treatment decisions. Methods. A survey was distributed among members of the Childhood Arthritis and Rheumatology Research Alliance using a web-based questionnaire. Results. 121 of 277 (41%) attending physician members completed the survey. Plain radiographs (89%) were most commonly used followed by regional MRI (78%), bone scintigraphy (43%), and whole-body MRI (36%). The top three reasons for performing a biopsy were constitutional findings (66%), unifocal bone lesions (64%), and nocturnal bone pain (45%). Nearly all responders (95%) prescribed nonsteroidal anti-inflammatory drugs (NSAIDs) as initial therapy. For patients who failed NSAID treatment, methotrexate (67%), tumor necrosis factor inhibitors (65%), and bisphosphonates (46%) were the next most commonly used treatments. The presence of a spinal lesion increased the use of bisphosphonate treatment. Conclusion. The diagnostic approach and disease activity monitoring for CNO varied among surveyed physicians. Our survey findings provided important background for the development of consensus treatment plans for CNO.

Successful treatment of chronic recurrent multifocal osteomyelitis using low-dose radiotherapy : A case report

BACKGROUND

Chronic recurrent multifocal osteomyelitis (CRMO) is a rare autoinflammatory disease, which lacks an infectious genesis and predominantly involves the metaphysis of long bones. Common treatments range from nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids at first onset of disease, to immunosuppressive drugs and bisphosphonates in cases of insufficient remission. The therapeutic use of low-dose radiotherapy for CRMO constitutes a novelty.

CASE REPORT

A 67-year-old female patient presented with radiologically proven CRMO affecting the right tibia/talus and no response to immunosuppressive therapy. Two treatment series of radiation therapy were applied with an interval of 6 weeks. Each series contained six fractions (three fractions per week) with single doses of 0.5 Gy, thus the total applied dose was 6 Gy. Ten months later, pain and symptoms of osteomyelitis had completely vanished.

CONCLUSION

Radiotherapy seems to be an efficient and feasible complementary treatment option for conventional treatment refractory CRMO in adulthood. The application of low doses per fraction is justified by the inflammatory pathomechanism of disease.

Unexpectedly high incidences of chronic non-bacterial as compared to bacterial osteomyelitis in children

Historically, osteomyelitis was considered an infectious disorder. More recently, inflammatory mechanisms were recognized causing a significant proportion of pediatric osteomyelitis. This study was to compare characteristics of children with chronic non-bacterial (CNO) and bacterial osteomyelitis (BOM). A chart review of osteomyelitis patients from the departments of pediatrics, pediatric surgery, orthopedic surgery, and oral and maxillofacial surgery was conducted in a tertiary referral center, covering the years 2004-2014. Institutional incidences of CNO (n = 49) and BOM (n = 56) were comparable. Differentiation between CNO and BOM based on clinical or laboratory findings was mostly impossible. However, children with BOM more frequently presented with local inflammatory signs (47 vs. 68 %, p = 0.040), fever (12 vs. 38 %, p = 0.003), and abscesses (0 vs. 39 %, p < 0.001). Peripheral arthritis (14 vs. 0 %, p < 0.001), inflammatory bowel disease (10 vs. 2 %, p = ns), and hyperostosis (29 vs. 4 %, p = 0.001) were more common in CNO. Whole-body MRI was performed in 76 % of CNO patients, unveiling multifocal lesions in 80 % (CRMO). Though considered a rare disorder, institutional incidences of CNO were comparable to BOM, and the discrimination between CNO and BOM solely based on clinical aspects was mostly impossible. This is of special interest, since a correct and timely diagnosis is of utmost importance for long-term outcomes in both disorders. Whole-body MRIs should be considered in chronic osteomyelitis to (1) detect clinically inapparent lesions in CNO and (2) indirectly exclude (usually unifocal) chronic bacterial infections. Prospective studies are warranted to establish evidence-based diagnostic and therapeutic approaches to CNO.

Chronic nonbacterial osteomyelitis may be associated with renal disease and bisphosphonates are a good option for the majority of patients

AIM

The aim of this Italian study was to describe the clinical features, treatment options and outcomes of a cohort of patients with chronic nonbacterial osteomyelitis (CNO).

METHODS

This was a retrospective cohort study. Laboratory data, diagnostic imaging, histological features and clinical course are reported.

RESULTS

We enrolled 47 patients diagnosed with CNO. Bone pain was the leading symptom, and multifocal disease was present in 87% of the patients. The majority of the bone lesions were located in the appendicular skeleton (58%). Extraosseous manifestations were present in 34% of the patients, and renal involvement was detected in four patients. Inflammatory indices were increased in 80%, and bone x-rays were negative in 15% of the patients. Nonsteroidal anti-inflammatory drugs (NSAIDs) were the first therapy for all patients, achieving clinical remission in 27%. A good response to NSAIDs was significantly associated with a better prognosis. Bisphosphonates were used in 26 patients, with remission in 73%. Only six patients (13%), all with spine involvement, developed sequelae.

CONCLUSION

We found a possible association between CNO and renal disease. Bisphosphonates were more likely to lead to clinical remission when NSAIDs and corticosteroids had failed. Vertebral localisation was the only risk factor for potential sequelae.

Pediatric Chronic Nonbacterial Osteomyelitis of the Jaw: Clinical, Radiographic, and Histopathologic Features

PURPOSE

Chronic nonbacterial osteomyelitis (CNO) is a focal sterile inflammatory osteitis in children that most commonly develops in the long bones, but can occur in any bone. The disease course is variable, ranging from acute and self-resolving isolated lesions to chronic recurrent multifocal osteomyelitis (CRMO), which is frequently associated with extraosseous inflammatory disease. The purpose of this study was to present our clinical experience with CNO of the mandible in children. The specific aims were to 1) document the clinical characteristics, radiographic findings, and histologic features of CNO and 2) determine the percentage of our sample with multifocal disease (CRMO).

MATERIALS AND METHODS

This is a retrospective case series of patients with mandibular CNO. To be included, patients had to have a mandibular lesion radiographically consistent with osteomyelitis without infection, onset before aged 18 years, and complete records. Medical records were reviewed for history, clinical features, imaging, and pathology. Descriptive data were summarized.

RESULTS

The sample included 22 patients (13 female and 9 male patients) with disease onset at a mean age of 9.05 ± 2.4 years. On presentation, all patients reported mandibular pain and swelling, and 45% had trismus. All had clinical and/or radiographic findings of multifocal intraosseous disease and/or extraosseous inflammatory lesions. Of the patients, 12 (54%) had a documented family history of autoimmune or autoinflammatory disease and 15 (68%) had elevated erythrocyte sedimentation rates during a flare. Computed tomography scans typically showed expansion of the affected mandible with sclerosis of the medullary space, small foci of poorly defined lytic destruction with a lamellated periosteal reaction, and swollen muscles of mastication. Four distinct histologic features were noted including parallel and interconnected osteoid seams, atypical osteoid, areas of woven bone and hypocellular fibroblastic stroma resembling fibrous dysplasia, and patchy nodular fibrosis.

CONCLUSION

Pediatric CNO of the mandible has characteristic radiographic and pathologic features and is usually found as one of multiple disease foci in CRMO rather than as an isolated lesion.

Whole-body MRI: non-oncological applications in paediatrics

Whole-body magnetic resonance imaging (WBMRI) is a fast and accurate method for detecting and monitoring of diseases throughout the entire body without exposure to ionizing radiation. Among emerging non-oncological potential applications of WBMRI, rheumatological diseases play an important role. Rheumatological WBMRI applications include the evaluation of chronic multifocal recurrent osteomyelitis, dermatomyositis, fever of unknown origin, arthritis, and connective tissue diseases. Aim of this review is to give an overview of the use of WBMRI in rheumatological field.

Chronic recurrent multifocal osteomyelitis with an atypical presentation in an adult man

We present the case of a 33-year-old man with no significant medical history who developed right scapular pain, left-sided sacroiliac joint pain, and lower back pain, and was eventually diagnosed with chronic recurrent multifocal osteomyelitis (CRMO). Imaging demonstrated multiple scattered T2-hyperintense lesions on MRI at the spine and the left SI joint, some of which progressed and one regressed in size on follow-up. Histopathology demonstrated only non-specific chronic inflammation compatible with CRMO. No evidence of infectious organisms or neoplastic processes was found. The pain was relapsing and remitting in nature. Laboratory investigations were notable for no evidence of hematologic malignancy or infection, but only a mild increase in alkaline phosphatase. This case highlights that CRMO, despite being thought of as a childhood-onset disease, can present in adults as well, and also provides illustrative examples of imaging and histological findings.

Chronic recurrent multifocal osteomyelitis: a rare skeletal disorder

Chronic recurrent multifocal osteomyelitis (CRMO) is a rare non-infectious inflammatory bone disease of unknown aetiology. CRMO mainly affects the metaphyses of long bones and spine in children and young adolescents. It presents with recurrent episodes of bone pain and fever, resembling bacterial osteomyelitis, but cultures of lesions are sterile and it is unresponsive to antibiotic therapy. We report a case of a 3-year-old boy diagnosed with CRMO, who was initially treated for bacterial osteomyelitis, and received prolonged antibiotic therapy for chronic pain, and swelling of mandible and ulna. CRMO should be kept in mind in the differential diagnosis of chronic bone pain and osteomyelitis unresponsive to antibiotic treatment.

Nonbacterial osteitis of the clavicle: longitudinal imaging series from initial diagnosis to clinical improvement

Nonbacterial osteitis is a rare autoinflammatory disease. Often it is mistaken for a tumor or osteomyelitis. We present a case of a twelve-year-old girl referred to our hospital because of a lesion of the right clavicle. The differential diagnoses were sarcoma, osteitis, and Langerhans cell histiocytosis. After biopsy the diagnosis nonbacterial osteitis (NBO) was established. Treatment of choice is a nonsteroidal anti-inflammatory drug. This case report gives a complete follow-up of the disease, showing the pitfalls of the diagnosis.