Consensus Treatment Plans for Chronic Nonbacterial Osteomyelitis Refractory to Nonsteroidal Antiinflammatory Drugs and/or With Active Spinal Lesions

Pamidronate for pain in adult chronic nonbacterial osteitis: protocol of a randomized, double-blind, placebo-controlled trial

Chronic nonbacterial osteitis (CNO) is a rare auto-inflammatory bone disease affecting children and adults. Adult CNO is characterized by painful bone lesions, primarily of the anterior chest wall. There is no approved therapy for adult CNO. Current off-label treatments include intravenous bisphosphonates, which have been shown to alleviate pain through decreasing bone turnover. However, no adequately powered randomized controlled trials (RCTs) have been conducted. This double-blind, placebo-controlled RCT investigates the efficacy of intravenous pamidronate to decrease bone pain in adult CNO patients. Recruiting at the Dutch national referral center for CNO, adult patients with persistent bone pain despite non-steroidal anti-inflammatory drugs, or optionally other standard-of-care treatments are randomized to receive two courses of intravenous pamidronate (at 0 and 3 mo, 30 mg daily, on 3 consecutive d) or placebo. From 6 mo onwards, all patients receive open-label pamidronate for another two courses. The primary outcome is change in score for maximum pain from 0 to 6 mo. Secondary outcomes include change in quantitative intralesional bone turnover as measured on sodium-fluoride positron emission computed tomography ([18F]NaF-PET/CT), inflammation markers, shoulder function, general health, quality of life, fatigue, physical, and work activity. The pamidronate for pain in adult chronic nonbacterial osteitis trial addresses the need for evidence-based treatments in adult CNO. Results will directly impact daily clinical practice, either validating the use of intravenous pamidronate in CNO at the dose used in this trial or prompting the search for alternative regimens or agents. This trial was registered in EudraCT (reference 2020-001068-27) and the Dutch Trial Register (reference NL68020.058.20).

Chronic Recurrent Multifocal Osteomyelitis Involving the Spine, Sternum, and Lower Extremities: A Case Report

Chronic recurrent multifocal osteomyelitis (CRMO) or chronic nonbacterial osteitis is a sterile autoinflammatory disease of bone in children that can mimic infectious osteomyelitis and osteosarcoma. Early diagnosis, treatment, and long-term follow-up of CRMO are essential. We describe a 10-year-old boy who presented with 15 days of left ankle bone more than joint pain, swelling, and limp. Plain radiographs and magnetic resonance imaging scans were nondiagnostic of osteomyelitis and tibial irrigation and biopsy were negative for infection and malignancy. Four years later, he again presented with similar pain in his right ankle. Repeat bone biopsy noted reactive bone changes and bone culture was sterile. Whole-body magnetic resonance imaging revealed multiple enhancing lesions in the long bones of bilateral lower extremities, spine, and sternum. He was diagnosed with CRMO, and treatment with celecoxib and subsequently pamidronate, infliximab, and methotrexate were initiated. After 6 months of treatment, the patient's gait and pain improved, and 2 years later, his CRMO was in clinical and radiologic remission. Of note, he developed palmoplantar pustular psoriasis, commonly seen in CRMO, that was not determined to be from tumor necrosis factor inhibition.

Spine Involvement and Vertebral Deformity in Patients Diagnosed with Chronic Recurrent Multifocal Osteomyelitis

BACKGROUND

Chronic recurrent multifocal osteomyelitis (CRMO) is an inflammatory disorder of bone, typically arising adjacent to the physes of long bones but also seen throughout the skeleton. For patients with spinal involvement, CRMO lesions can cause compression deformities with a range of severity from minimal anterior wedging to circumferential height loss, known as vertebra plana. This study examines a large cohort of CRMO patients to determine the prevalence of spine involvement and vertebral deformity.

METHODS

This is a retrospective review of all patients with a diagnosis of CRMO seen at our institution between January 2003 and December 2020. These patients were identified through a prospectively maintained database of all CRMO patients seen at the institution. A retrospective review was undertaken to identify all patients with spinal involvement and determine the prevalence of CRMO in the spine and its effects on vertebral height and deformity.

RESULTS

Of 170 patients included in this study, 48 (28.2%) were found to have spinal involvement. Among patients with spinal involvement, vertebral body lesions were identified in 27 (56.3%) patients. The remaining lesions were in the sacrum or posterior elements. Radiographic evidence of the vertebral body height loss was noted in 23 of these 27 patients.

CONCLUSIONS

This cohort of CRMO patients demonstrates that 28% of patients have spinal involvement, and 48% of those patients have vertebral body height loss. While the ideal treatment for spinal CRMO has yet to be determined, imaging studies, including whole-body MRI and spine-specific MRI, are useful in identifying vertebral lesions and deformities. Identification and surveillance of these lesions are important as the disorder has a relapsing and remitting course, and patients can develop significant vertebral body height loss. Once deformity has developed, we have seen no evidence of reconstitution of the height of the collapsed vertebra. Bisphosphonates have been successful in preventing the progression of vertebral body height loss.

LEVEL OF EVIDENCE

Level II: Retrospective study investigating spinal involvement and prevalence of vertebral body deformity in patients diagnosed with CRMO.

Coexisting Sacroiliac Arthritis and Chronic Nonbacterial Osteomyelitis in an Adolescent with Ehlers-Danlos Syndrome: A Case Report and Treatment Success

BACKGROUND Chronic nonbacterial osteomyelitis (CNO) is a multifocal autoinflammatory bone disease mainly affecting children and adolescents. Sacroiliitis is an inflammation of the sacroiliac joint, diagnosed with the use of musculoskeletal MRI due to its ability to visualize active inflammatory lesions. Ehlers-Danlos syndrome (EDS) is non-inflammatory hereditary disorder of connective tissue. Here, we report the case of a 17.5-year-old female patient with classical EDS and long-term course of the CNO with coexistence of sacroiliac arthritis. CASE REPORT On admission, a patient with CNO reported pain in the scapula, thoracic spine, shoulders, and iliac region, with morning stiffness present for 5 months. Physical examination revealed knee and elbow joint hyperextension, hypermobility of the phalanges, increased range of motion of the hip joints, and the presence of reticular rash on the face. In the laboratory blood tests, minor leukocytosis was reported. During hospitalization, a whole-body MRI was performed, detecting bone marrow edema in the Th3, Th4, and Th7 vertebral bodies and the head of seventh rib on the left side, as well as bilaterally in the sacroiliac joints. The patient was diagnosed with sacroiliitis and EDS and successfully treated with risedronate sodium, methotrexate with folic acid, sulfasalazine, and meloxicam, achieving CNO remission and reduced severity of axial skeleton pain. CONCLUSIONS The coexistence of these 3 diseases - CNO, sacroiliac arthritis, and EDS - in the same patient is rare and requires interphysician collaboration to determine the correct diagnosis and subsequently arrange multi-speciality therapeutic management to achieve remission.

Extra-osseous manifestations in chronic recurrent multifocal osteomyelitis: a retrospective study

OBJECTIVES

Extra-osseous (EO) manifestations are poorly characterized in chronic recurrent multifocal osteomyelitis (CRMO). This study aimed to further define the frequency, characteristics and treatment of EO events in CRMO and whether different phenotypes can be distinguished and benefit from special management.

METHODS

This multicentre retrospective study included CRMO patients followed in several paediatric rheumatology departments in France between 2015 and 2022. EO manifestations were defined as skin lesions, gastrointestinal manifestations, arthritis, enthesitis, sacroiliitis, uveitis, vasculitis and fever. At the last visit, the physician defined CRMO as active in the presence of clinical manifestations including both osseous and EO symptoms.

RESULTS

We included 133 patients; 87 (65.4%) were girls and the median age at first symptoms was 9.0 years (interquartile range 7.0-10.0). EO manifestations were described in 90 (67.7%) patients, with a predominance of skin lesions [n = 51/90 (56.7%)], followed by sacroiliitis [n = 38/90 (42.2%)], enthesitis [n = 21/90 (23.3%)], arthritis [n = 14/90 (15.6%)] and gastrointestinal manifestations [n = 6/90 (6.7%)]. The use of non-steroidal anti-inflammatory drugs and bisphosphonates did not differ by the presence or not of EO manifestations. Biologics were taken more frequently by patients with than without EO manifestations (P < 0.001); TNF inhibitors were used in 33 (36.7%) EO-positive patients. Under this treatment, 18 (54.5%) patients achieved complete remission of osseous and EO manifestations. At the last visit, more EO+ than EO- patients were on treatment (P = 0.009), with active disease in 58 (64.4%) patients.

CONCLUSION

The analysis of EO manifestations in CRMO delineates two groups of patients in terms of severity and treatments used. Our study opens up new pathophysiological leads that may underlie the wide range of CRMO phenotypes.

Chronic non-bacterial osteomyelitis (CNO) and chronic recurrent multifocal osteomyelitis (CRMO) with a focus on pamidronate therapy

Chronic recurrent multifocal osteomyelitis (CRMO), also called chronic nonbacterial osteomyelitis (CNO) or nonbacterial osteomyelitis (NBO), is a rare autoinflammatory bone disease of unknown etiology. However, the number of patients properly diagnosed would increase with better knowledge of the disease. In this regard, whole-body magnetic resonance imaging (WB MRI) has been found to be a better predictor of active lesions than clinical examination. Importantly, the RINBO index (radiologic index for NBO) quantifies the involvement based on the WB MRI. Further, a chronic nonbacterial osteomyelitis MRI scoring (CROMRIS) has been developed as an online tool for assessing WB MRI. The therapy consists of non-steroidal anti-inflammatory drugs (NSAIDs), bisphosphonates (pamidronate, zoledronate, etc.) and other drugs, including biologics. Pamidronate is an appropriate and safe therapy. The first pilot prospective randomised controlled trial (RCT) on pamidronate vs. placebo was carried out in adults. No RCT has been done in children yet. Besides RCTs, there are a number of issues to be explored in future, i.e. predictors of therapy effect, optimal therapy duration, predictors of therapy discontinuation and evaluation of optimal therapy protocol. Recently, the CNO clinical disease activity score (CDAS) was constructed and validated but the classification criteria are still being developed. As collaboration on this rare disease is essential, a prospective Chronic Nonbacterial Osteomyelitis International Registry (CHOIR) was established to generate future comparative effectiveness research data.

An interactive dose optimizer based on population pharmacokinetic study to guide dosing of methotrexate in Chinese patients with osteosarcoma

PURPOSE

Osteosarcoma is a rare tumor with an incidence of 4.4 cases per million per year in adolescent. High-dose methotrexate (HD-MTX) is the standard first-line chemotherapeutic agent for osteosarcoma. However, its efficacy can vary significantly among individuals due to wide pharmacokinetic variability. Despite this, only a few population pharmacokinetics (popPK) models based on Chinese patients with osteosarcoma have been reported. Thus, this study aimed to develop a HD-MTX popPK model and an individual model-based dose optimizer for osteosarcoma therapy.

METHOD

A total of 680 MTX serum concentrations from 57 patients with osteosarcoma were measured at the end of MTX infusion and 10 h, 24 h, 48 h, and 72 h after the start of infusion. Using the first-order conditional estimation method with NONMEM, a popPK model was estimated. Goodness-of-fit plots, visual predictive checks, and bootstrap analysis were generated to evaluate the final model. A dose optimizer tool was developed based on the validated models using R Shiny. Additionally, clinical data from 12 patients with newly diagnosed osteosarcoma were collected and used as the validation set to preliminarily verify the predictive ability of the popPK model and the dose optimizer tool.

RESULTS

Body surface area (BSA) was the most significant covariate for compartment distribution. Creatinine clearance (CrCL) and co-administration of NSAIDs were introduced as predictors for central compartmental and peripheral compartmental clearance, respectively. Co-administration of NSAIDs was associated with significantly higher MTX concentrations at 72 h (p = 0.019). The dose optimizer tool exhibited a high consistency in predicting MTX AUC compared to the actual AUC (r = 0.821, p < 0.001) in the validation set.

CONCLUSION

The dose optimizer tool could be used to estimate individual PK parameters, and optimize personalized MTX therapy in particular patients.

Chronic recurrent multifocal osteomyelitis: Case report and review of the literature

BACKGROUNDS

Chronic recurrent multifocal osteomyelitis (CRMO) is a rare inflammatory disease.

OBJECTIVE

This report aims to analyze the clinical characteristics of CRMO and enhance clinicians' comprehension. We present 3 atypical cases, highlighting their unique clinical features, diagnostic challenges, and effective treatment strategies.

METHODS

We retrieved 3 CRMO cases in our hospital from September 2019 to August 2022. The clinical features were analyzed retrospectively, and relevant literatures were reviewed.

RESULTS

All 3 cases initially presented with bone pain, normal leucocyte counts, negative rheumatoid factors and no signs of sclerotic or hyperostotic lesions. Case 1, a 12-year-old girl, exhibited concurrent acne on the forehead and historic necrotizing lymphadenitis, a previously unreported association with CRMO. Case 2, a 14-year-old boy, tested positive for human leukocyte antigen-B27 and displayed scoliosis along with multifocal osteomyelitis. Case 3, a 9-year-old girl, presented with scoliosis, and chest computed tomography revealed changes in the T8 vertebral body, initially suggesting Langerhans cell histiocytosis. Bone biopsy was conducted in case 1 and case 3, revealing chronic inflammation. All 3 cases affected long bones, pelvis, and vertebra, involving 8, 6 and 5 bones, respectively, identified by magnetic resonance imaging. Genetic analysis was undertaken in cases 1 and 2 but no pathogenic mutations were identified. Upon the confirmation of a CRMO diagnosis, all patients were initiated on a treatment regimen comprising nonsteroidal anti-inflammatory drugs and tumor necrosis factor-α inhibitors. In cases 1 and 2, due to the severity of their bone pain, they were also administered to disease-modifying anti-rheumatic drugs, specifically methotrexate. All 3 patients achieved remission of bone pain. To gain a more comprehensive understanding of CRMO, we conducted a thorough review of relevant literature.

CONCLUSION

CRMO is a rare autoinflammatory bone disorder with diverse clinical presentations and a lack of specific laboratory tests, which leads to potency to misdiagnosis or delayed diagnosis. By raising awareness and improving diagnostic criteria, physicians are now better equipped to identify CRMO. We contribute to share our understanding of CRMO by presenting 3 cases with untypical clinical features, highlighting the importance of recognizing this rare condition for timely and effective management.

Successful treatment of erythema nodosum with salazosulfapyridine in a 9-year-old patient with chronic non-bacterial osteomyelitis

We report a 9-year-old Japanese girl with chronic non-bacterial osteomyelitis (CNO) accompanied by recurrent erythema nodosum (EN) which was successfully treated with salazosulfapyridine (SASP). She was referred to our hospital because of recurrent erythema on her lower extremities and persistent knee and ankle arthralgia, which had been present for approximately 1 year. Although naproxen, a nonsteroidal anti-inflammatory drug, was initiated, her symptoms frequently recurred. Magnetic resonance imaging demonstrated multiple distinct high-intensity signals in the talus bones suggestive of multiple bone oedemas. Additionally, a histological examination of erythematous lesions was consistent with the histopathological findings of EN. She was diagnosed as having CNO complicated by EN, and received 250 mg/day of SASP as a second-line treatment, which showed partial response of both skin and bone lesions. Following increase in the dose of SASP to 500 mg/day resulted in complete remission of her skin and bone lesions. In conclusion, our findings suggest that SASP is effective not only for CNO bone lesions but also for EN. SASP could serve as a second-line therapeutic option at least for some cases of CNO complicated by EN refractory to nonsteroidal anti-inflammatory drugs.

Childhood Arthritis and Rheumatology Research Alliance Biologic Disease-Modifying Antirheumatic Drug Consensus Treatment Plans for Refractory Moderately Severe Juvenile Dermatomyositis

OBJECTIVE

The objective was to develop consensus treatment plans (CTPs) for patients with refractory moderately severe juvenile dermatomyositis (JDM) treated with biologic disease-modifying antirheumatic drugs (bDMARDs).

METHODS

The Biologics Workgroup of the Childhood Arthritis and Rheumatology Research Alliance JDM Research Committee used case-based surveys, consensus framework, and nominal group technique to produce bDMARD CTPs for patients with refractory moderately severe JDM.

RESULTS

Four bDMARD CTPs were proposed: tumor necrosis factor α (TNFα) inhibitor (adalimumab or infliximab), abatacept, rituximab, and tocilizumab. Each CTP has different options for dosing and/or route. Among 76 respondents, consensus was achieved for the proposed CTPs (93% [67 of 72]) as well as for patient characteristics, assessments, outcome measures, and follow-up. By weighted average, respondents indicated that they would most likely administer rituximab, followed by abatacept, TNFα inhibitor, and tocilizumab.

CONCLUSION

CTPs for the administration of bDMARDs in refractory moderately severe JDM were developed using consensus methodology. The implementation of the bDMARD CTPs will lay the groundwork for registry-based prospective comparative effectiveness studies.

Molecular Imaging with PET-CT and PET-MRI in Pediatric Musculoskeletal Diseases

Molecular imaging has emerged as an integral part of oncologic imaging. Given the physiologic changes that precede anatomic changes, molecular imaging can enable early detection of disease and monitoring of response. [18F] Fluorodeoxyglucose (FDG) Positron emission tomography (PET) is the predominant molecular imaging modality used in oncologic assessment and can be performed using PET/CT or PET/MR. In pediatric patients, PET/MRI imaging is generally preferred due to low radiation exposure and PET/MRI is particularly advantageous for imaging musculoskeletal (MSK) diseases, as MRI provides superior characterization of tissue changes as compared to CT. In this article, we provide an overview of the typical role of PET CT/MRI in assessment of some common pediatric malignancies and benign MSK diseases with case examples. We also discuss the relative advantages of PET/MRI compared to PET/CT, and review published data with a primary focus on the use of PET/MR.

Collaborative approach to paediatric chronic non-bacterial osteomyelitis of the mandible: Great Ormond Street Hospital case series

This paper outlines a 10-patient case series of chronic non-bacterial osteomyelitis (CNO) of the mandible at a tertiary paediatric hospital in the UK. Our findings highlight the homogeneous presenting signs and symptoms of an intermittently painful, swollen angle and ramus of the mandible. We present the typical laboratory investigative findings (normal inflammatory markers) and imaging appearances (sclerosis and periosteal oedema). Our paper outlines an investigation protocol, including recommendations for extraoral bone biopsies and systemic magnetic resonance imaging (MRI). We explain the importance of multidisciplinary care, with combined care by rheumatologists and infectious disease specialists. Finally we demonstrate the efficacy of our treatment algorithm for oral non-steroidal anti-inflammatory drugs (NSAIDs), and in those cases refractory to NSAIDS, intravenous pamidronate. This paper provides a useful addition to the literature by informing OMF surgeons of this rare condition and given the clinical equipoise in treatments, it can hopefully guide clinicians in an investigation pathway and management protocol.

Chronic Non-bacterial Osteomyelitis (CNO) In Childhood: A Review

Chronic non-bacterial osteomyelitis (CNO) is an autoinflammatory bone disorder mostly affecting children and adolescents. Although it is considered a rare disease, CNO is likely to be the single most common autoinflammatory bone disease in childhood, underdiagnosed and underreported due to a lack of awareness of the condition in both medics and patients and the absence of validated diagnostic criteria. The exact underlying pathogenesis of CNO remains unknown, making targeted treatment difficult. This issue is exacerbated by the lack of any randomised control trials, meaning that treatment strategies are based solely on retrospective reviews and case series. This review summarises the current concepts in pathophysiology, the clinical features that help differentiate important differential diagnoses, and an approach to investigating and managing children with CNO. Ultimately, the timely and thorough investigation of children and young people with CNO is vitally important to exclude important mimics and initiate appropriate management that can prevent the complications of persistent inflammatory bone disease.

Treatment and monitoring of SAPHO syndrome: a systematic review

BACKGROUND AND OBJECTIVES

Synovitis acne pustulosis hyperostosis osteitis (SAPHO) is a rare heterogeneous disease of unknown aetiopathology. Externally validated and internationally agreed diagnostic criteria or outcomes and, as a result, prospective randomised controlled trials in SAPHO are absent. Consequently, there is no agreed treatment standard. This study aimed to systematically collate and discuss treatment options in SAPHO.

METHODS

Following 'Preferred Reporting Items for Systematic Reviews and Meta-Analyses' guidance, a systematic literature search was conducted using PubMed, Scopus and Web of Science databases. Prospective clinical studies and retrospective case collections discussing management and outcomes in SAPHO involving five or more participants were included. Articles not published in English, studies not reporting defined outcomes, and studies solely relying on patient-reported outcomes were excluded.

RESULTS

A total of 28 studies (20 observational, 8 open-label clinical studies) reporting 796 patients of predominantly European ethnicity were included. Reported therapies varied greatly, with many centres using multiple treatments in parallel. Most patients (37.1%) received non-steroidal anti-inflammatory drugs alone or in combination. Bisphosphonates (22.1%), conventional (21.7%) and biological (11.3%) disease-modifying antirheumatic drugs were the next most frequently reported treatments. Reported outcomes varied and delivered mixed results, which complicates comparisons. Bisphosphonates demonstrated the most consistent improvement of osteoarticular symptoms and were associated with transient influenza-like symptoms. Paradoxical skin reactions were reported in patients treated with TNF inhibitors, but no serious adverse events were recorded. Most treatments had limited or mixed effects on cutaneous involvement. A recent study investigating the Janus kinase inhibitor tofacitinib delivered promising results in relation to skin and nail involvement.

CONCLUSIONS

No single currently available treatment option sufficiently addresses all SAPHO-associated symptoms. Variable, sometimes descriptive outcomes and the use of treatment combinations complicate conclusions and treatment recommendations. Randomised clinical trials are necessary to generate reliable evidence.

Chronic Nonbacterial Osteomyelitis in Inflammatory Bowel Disease

Chronic nonbacterial osteomyelitis (CNO), also known as chronic recurrent multifocal osteomyelitis (CRMO), is a rare autoinflammatory bone disease primarily affecting children and adolescents. This review presents a comprehensive analysis of the intricate relationship between CNO and inflammatory bowel disease (IBD), shedding light on shared pathophysiological mechanisms and clinical management. A thorough literature review was conducted, encompassing 24 case reports involving 40 patients. The demographic distribution of patients revealed a near-equal gender ratio, with a median age of diagnosis at 12 years. The diagnosis patterns showed a higher proportion of CNO as the initial diagnosis, while Crohn's disease was more prevalent than ulcerative colitis. The time interval between the clinical presentations varied, ranging from simultaneous detection to a substantial 15-year gap. Treatment modalities included nonsteroidal anti-inflammatory drugs (NSAIDs), steroids, aminosalicylates, and biologic agents, such as infliximab, often overlapping in their use and suggesting shared pathophysiological pathways. Both conditions displayed systemic manifestations, and patients often responded well to immunosuppressive medications. The pathophysiology of CNO involves a genetic predisposition, cytokine dysregulation, and osteoclast activation. Dysregulated innate immunity results in immune cell infiltration into bones, causing sterile bone lesions. Notably, emerging evidence hints at a potential link between the microbiome and CNO. In contrast, IBD results from imbalanced mucosal immune responses to the intestinal microbiota. Polymorphisms in the promotor region of IL-10, common cytokines, immune cells, and genetic markers indicate shared immunological and genetic factors between CNO and IBD. Both conditions also involve extraintestinal symptoms. This analysis underscores the need for clinical awareness of the co-occurrence of CNO and IBD, especially among pediatric patients. A deepened understanding of the connections between these seemingly distinct diseases could lead to more effective management and improved patient outcomes.

Long-term follow-up of children with chronic non-bacterial osteomyelitis-assessment of disease activity, risk factors, and outcome

INTRODUCTION

Chronic non-bacterial osteomyelitis (CNO) is an autoinflammatory bone-disease of unknown origin. The National Pediatric Rheumatologic Database (NPRD) collects long-term data of children and adolescents with rheumatic diseases including CNO.

OBJECTIVE

To assess characteristics, courses, and outcomes of CNO with onset in childhood and adolescence and to identify outcome predictors.

METHODS

From 2015 to 2021 patients with a confirmed diagnosis of CNO, who were registered in the NPRD during their first year of disease and at least one follow-up visit, were included in this analysis and observed for up to 4 years.

RESULTS

Four hundred patients with recent diagnosis of CNO were enrolled in the NRPD during the study period. After 4 years, patient data documentation was sufficient to be analyzed in 81 patients. A significant decline of clinical and radiological lesions is reported: at inclusion in the registry, the mean number of clinical lesions was 2.0 and 3.0 MRI lesions per patient. A significant decrease of manifestations during 4 years of follow-up (mean clinical lesions 0.5, p < 0.001; mean MRI lesions 0.9 (p < 0.001)) was documented. A significant improvement of physician global disease activity (PGDA), patient-reported overall well-being, and childhood health assessment questionnaire (C-HAQ) was documented. Therapeutically, an increase of disease-modifying anti-rheumatic drugs over the years can be stated, while bisphosphonates rather seem to be considered as a therapeutic DMARD option in the first years of disease. Only 5-7% of the patients had a severe disease course as defined by a PGDA >  = 4. Predictors associated with a severe disease course include the site of inflammation (pelvis, lower extremity, clavicle), increased erythrocyte sedimentation rate, and multifocal disease at first documentation. The previously published composite PedCNO disease activity score was analyzed revealing a PedCNO70 in 55% of the patients at 4YFU.

CONCLUSION

An improvement of physician global disease activity (PGDA), patient reported overall well-being and imaging-defined disease activity measures was documented, suggesting that inactivity of CNO disease can be reached. PedCNO score and especially PGDA, MRI-defined lesions and in a number of patients also the C-HAQ seem to be reliable parameters for describing disease activity. The identification of risk factors at the beginning of the disease might influence treatment decision in the future.

Feasibility of Conducting Comparative Effectiveness Research and Validation of a Clinical Disease Activity Score for Chronic Nonbacterial Osteomyelitis

OBJECTIVE

Prospective comparative effectiveness research (CER) in chronic nonbacterial osteomyelitis (CNO) is lacking. Our objectives were to (1) determine the use and safety of each consensus treatment plan (CTP) regimen for CNO, (2) assess the feasibility of using the Chronic Nonbacterial Osteomyelitis International Registry (CHOIR) data for CER, and (3) develop and validate a CNO clinical disease activity score (CDAS) using CHOIR.

METHODS

Consenting children or young adults with CNO were enrolled into CHOIR. Demographic, clinical, and imaging data were prospectively collected. The CNO CDAS was developed through a Delphi survey and nominal group technique. External validation surveys were administered to CHOIR participants.

RESULTS

One hundred forty (78.2%) CHOIR participants enrolled between August 2018 and September 2020 received at least 1 CTP regimen. Baseline characteristics from different CTP groups were well matched. Patient pain, patient global assessment, and clinical CNO lesion count were key variables included in the CNO CDAS. The CDAS showed a strong correlation with patient/parent report of difficulty using a limb, back, or jaw and patient/parent report of disease severity, but a weak correlation with patient/parent report of fatigue, sadness, and worry. The change in CDAS was significant in patients reporting disease worsening or improvement (P < 0.001). The CDAS significantly decreased after initiating second-line treatments from median 12.0 (IQR 8.0-15.5) to 5.0 (IQR 3.0-12.0; P = 0.002). Although second-line treatments were well tolerated, psoriasis was the most common adverse event.

CONCLUSION

The CNO CDAS was developed and validated for disease monitoring and assessment of treatment effectiveness. CHOIR provided a comprehensive framework for future CER.

Golimumab in Children with Chronic Recurrent Multifocal Osteomyelitis: A Case Series and Review of the Literature

BACKGROUND

Chronic recurrent multifocal osteomyelitis (CRMO) is a rare autoinflammatory bone disease requiring immunosuppressive treatment in half of patients. Monoclonal tumor necrosis factor inhibitors (TNFi) are often used as effective second-line off-label therapies. However, paradoxical psoriasis can occur in a subset of patients exposed to monoclonal TNFi and can prompt conversion to alternate therapy if severe.

OBJECTIVE

The aim of this study was to determine the efficacy and safety of golimumab, a fully humanized TNFi, in children with CRMO, including those who develop paradoxical psoriasis after exposure to other monoclonal TNFi.

METHODS

A retrospective chart review was conducted of patients with CRMO who received golimumab in a single center between 01 June, 2018 and 31 December, 2020. Patients who were diagnosed before 21 years of age and followed up for CRMO at least once after receiving ≥ 3 months of golimumab were included. Extracted data included patient demographics, whole-body MRI lesion counts, clinically relevant data, laboratory results, patient-reported outcomes, and psoriasis burden. Linear mixed models with log-transformed outcomes were used to assess changes in the outcomes over time. The random effect is included in the model to account for the within-subject correlation of repeated measures. p-values and 95% confidence intervals were reported.

RESULTS

Eighteen patients were included. Patients were observed for a median of 9.95 months [interquartile range 3.84-15.64]. The median age at the initiation of golimumab was 10.95 years [9.86-13.77] and the median duration of disease between the disease onset and the initiation of golimumab was 2.60 years [1.66-3.62]. Ten patients received golimumab via intravenous route and eight patients received golimumab via subcutaneous route. The median dose was 1.64 mg/kg/month [1.46, 2]. Fourteen patients were previously treated with disease-modifying antirheumatic drugs and 17 with other TNFi. Patients treated with golimumab showed significant improvement in median physician global assessment for CRMO from 2.00 [1.00-3.00] to 0.00 [0.00-0.25] by the fourth visit (p < 0.001), with median erythrocyte sedimentation rate (ESR) decreasing significantly from 12.00 [6.75-23.75] to 5.00 [3.00-10.00] by the fourth visit (p < 0.05). The median number of lesions on MRI decreased significantly from 3.50 [2.00-5.50] to 0.50 [0.00-4.25] lesions per patient (p < 0.01). Nine out of 12 patients who had previous paradoxical psoriasis associated with adalimumab or infliximab had persistent active psoriasis at study baseline. For patients with psoriasis at study baseline, the prevalence of psoriasis had decreased from 100% to approximately 50-57% at the following visits. Of the 18 patients initiated on golimumab in this study, there was only one new case of mild psoriasis in a patient with previously resolved infliximab-associated paradoxical psoriasis. No serious infections or adverse events were noted during the study. Two patients in the study showed clinical improvement with concomitant golimumab and ustekinumab with no reported adverse side effects or increased effects in these patients over a 16-month interval, showing that this combination can be safe and effective for children with CRMO.

CONCLUSION

In our experience, golimumab has been shown to be a safe and effective therapy for CRMO and demonstrated improvement in paradoxical psoriasis in many patients. Longer follow-up periods would be helpful to develop longer term outcomes data for patients with CRMO and overall paradoxical psoriasis risk.

MRI features of spinal chronic recurrent multifocal osteomyelitis/chronic non-bacterial osteomyelitis in children

BACKGROUND

Spinal lesions in pediatric chronic recurrent multifocal osteomyelitis/chronic non-bacterial osteomyelitis (CRMO/CNO) can cause permanent sequelae; thus, early recognition of these is vital for management.

OBJECTIVE

To characterize the MR imaging features and patterns of pediatric spinal CRMO/CNO.

MATERIALS AND METHODS

This cross-section study received IRB approval. The first available MRI with documented spine involvement in children with CRMO/CNO was reviewed by a pediatric radiologist. Descriptive statistics were used to describe the characteristics of vertebral lesions, disc involvement, and soft tissue abnormality.

RESULTS

Forty-two patients were included (F:M, 30:12); median age was 10 years (range 4-17). At diagnosis, 34/42 (81%) had spine involvement. Kyphosis in 9/42 (21%) and scoliosis in 4/42 (9.5%) patients were present at the time of spinal disease recognition. Vertebral involvement was multifocal in 25/42 (59.5%). Disc involvement was found in 11/42 (26%) patients, commonly in the thoracic spine and often with adjacent vertebrae height loss. Posterior element abnormalities were present in 18/42 patients (43%) and soft tissue involvement in 7/42 (17%). One hundred nineteen vertebrae were affected, commonly the thoracic vertebrae (69/119; 58%). Vertebral body edema was focal in 77/119 (65%) and frequently superior (42/77; 54%). Sclerosis and endplate abnormality were present in 15/119 (13%) and 31/119 (26%) vertebrae, respectively. Height loss was present in 41/119 (34%).

CONCLUSION

Chronic non-bacterial osteomyelitis of spine is usually thoracic. Vertebral body edema is often focal at the superior vertebral body. Kyphosis and scoliosis occur in a quarter and vertebral height loss in a third of children at spinal disease recognition.

An unusual presentation of chronic recurrent multifocal osteomyelitis involving bones of the skull

Chronic recurrent multifocal osteomyelitis is a rare, multisystemic inflammatory disease that affects children and adolescents. We present the case of an African-American adolescent male who presented with recurrent swelling of the temporal region with skull involvement on head imaging, which is atypical for chronic recurrent multifocal osteomyelitis. He had clinical and laboratory improvement after initiation of indomethacin and pamidronate.

Chronic Recurrent Multifocal Osteomyelitis: A Comprehensive Literature Review

Chronic recurrent multifocal osteomyelitis (CRMO) is a non-infectious, inflammatory disorder of the bones. CRMO typically affects children, with a predisposition to females. Bone-related pain is often felt in the metaphysis of long bones, particularly of the lower extremities, but it can also target other sites at varied time intervals. Patients are likely to complain of tenderness and swelling that may cause considerable disability and adversely impact quality of life. There are three main pathophysiological mechanisms that have been hypothesized to drive CRMO including imbalanced cytokine expression, increased inflammasome activation, and enhanced osteoclast differentiation. Therapies have been based on targeting and suppressing these key players in CRMO patients. The first step in management involves pain control. Non-steroidal anti-inflammatory drugs should provide initial relief, albeit temporarily. It is imperative to initiate immunosuppressive medication that will help limit bone involvement and thereby prevent the development of fractures or leg-length discrepancies, for example. The purpose of this literature review is to study the pathophysiology of CRMO and carefully dissect the agents that have been previously employed in the management of CRMO patients. This could allow for the purposeful formulation of individualized care plans and improving the overall well-being of patients. The authors included a multitude of PubMed-indexed articles published from 2000 onwards in this review.

Update on treatment responses and outcome measure development in chronic nonbacterial osteomyelitis (CNO)

PURPOSE OF REVIEW

To review recent trends in treatment and recent progress in developing outcome measures needed for chronic nonbacterial osteomyelitis (CNO) clinical trials.

RECENT FINDINGS

CNO is an autoinflammatory bone disease. In a minority of patients, the disease is genetically driven, and diagnosis can be made by DNA sequencing. However, for nonsyndromic CNO there is no diagnostic test. The number of children with CNO appears to be increasing and damage is common. Increases in CNO diagnosis is due to raised awareness, increased availability of whole-body magnetic resonance imaging and rising incidence. Treatment remains empiric and it is unclear which second line treatment is superior. Tumor necrosis factor inhibitors (TNFi) and bisphosphonates continue to be used as second line agents for nonsteroidal anti-inflammatory drugs (NSAID) refractory CNO; newer immune modulatory medications are used if this fails. Validated classification criteria, clinical outcome measures and imaging scoring standards are needed for successful clinical trials.

SUMMARY

Best treatment for NSAID refractory CNO remains unclear. Classification criteria, clinical outcomes measures and standardized imaging scoring have been developed or are near completion. This will facilitate robust clinical trials in CNO with the goal of having approved medications for this painful disease.

Classification and management strategies for paediatric chronic nonbacterial osteomyelitis and chronic recurrent multifocal osteomyelitis

INTRODUCTION

Chronic non-bacterial osteomyelitis (CNO) is an autoinflammatory bone disease that most commonly affects children and adolescents causing significant pain and damage to bones. The absence of diagnostic criteria and biomarkers, an incomplete understanding of the molecular pathophysiology, and lack of evidence from randomized and controlled trials make the diagnosis and care challenging.

AREAS COVERED

This review provides an overview of the clinical and epidemiological features of CNO and displays diagnostic challenges and how they can be addressed following strategies used internationally and by the authors. It summarizes the molecular pathophysiology, including pathological activation of the NLRP3 inflammasome and IL-1 secretion, and how these observations can inform future treatment strategies. Finally, it provides a summary of ongoing initiatives aiming at classification criteria (ACR/EULAR) and outcome measures (OMERACT) that will enable the generation of evidence through clinical trials.

EXPERT OPINION

Scientific efforts have linked molecular mechanisms to cytokine dysregulation in CNO, thereby delivering arguments for cytokine blocking strategies. Recent and ongoing collaborative international efforts are providing the basis to move toward clinical trials and target directed treatments for CNO that find approval by regulatory agencies.

Pediatric autoinflammatory bone disorders-a mini review with special focus on pathogenesis and inborn errors of immunity

Autoinflammatory bone disorders are a group of diseases characterized by sterile osteomyelitis. This includes chronic nonbacterial osteomyelitis and the monogenic forms, Majeed syndrome and deficiency of the interleukin-1 receptor antagonist. These disorders result from innate immune system dysregulation and cytokine imbalance that triggers inflammasome activation causing downstream osteoclastogenesis and excessive bone remodeling. In this review, we will summarize the immunopathogenesis of pediatric autoinflammatory bone diseases with a special focus on the genetics and inborn errors of immunity, while briefly touching on the clinical manifestations and management of each disease as well as areas for future research.

HLA-B*27 is associated with CNO in a European cohort

OBJECTIVES

To determine the influence of HLA-B27 positivity on risk of developing chronic nonbacterial osteomyelitis (CNO).

METHODS

HLA-B*27 genotype was assessed in 3 European CNO populations and compared with local control populations (572 cases, 33,256 controls). Regional or whole-body MRI was performed at diagnosis and follow-up in all cases which reduces the risk of disease misclassification. Genotyping was performed using either next generation DNA sequencing or PCR based molecular typing. Statistical analysis used Fisher's exact test with Bonferroni correction and a fixed effects model for meta-analysis of odds ratios.

RESULTS

HLA-B*27 frequency was higher in all 3 populations compared with local controls (combined odds ratio (OR) = 2.2, p-value = 3 × 10^-11). This association was much stronger in male compared with female cases (OR = 1.99, corrected p-value = 0.015). However, the HLA-B*27 status was not statistically significantly associated with co-occurrence of psoriasis, arthritis or inflammatory bowel disease.

CONCLUSION

Carriage of HLA-B*27 is associated with greater risk of developing CNO, particularly in male cases.

Juvenile idiopathic arthritis with systemic onset with inflammatory bone lesions: two case reports of patients successfully treated with canakinumab and experience gained from literature

Non-bacterial osteomyelitis (NBO) is a rare chronic inflammatory bone disease related to immune system dysregulation. This disease belongs to a family of autoinflammatory diseases. It often coexists with other TNF-α-mediated immune-mediated diseases such as juvenile idiopathic arthritis (JIA) and inflammatory bowel diseases. Previously, interleukin-1-driven inflammation was described predominantly in monogenic cases of NBO, such as DIRA syndrome or Majeed syndrome. However, the association between NBO and JIA with systemic onset (soJIA) has not been described yet. Herein, we describe the cases of two patients with soJIA with inflammatory bone lesions wherein canakinumab (anti-interleukin-1β antibodies) caused remission.

Case descriptions

Patient 1-A 6-month-old boy with typical soJIA suffered a destruction of the 7th to 9th ribs and the left pubic bone. Antibiotics, IVIG, and cyclosporine proved ineffective. Corticosteroids were effective, but due to the factor of corticosteroid dependence, which has some disadvantages, canakinumab with a dosage of 4 mg/kg was initiated every 4 weeks, which completely controlled the disease and allowed to taper corticosteroids.Patient 2-A 2-year-old girl developed chronic non-bacterial osteomyelitis of the 5th rib 2 months after taking corticosteroids prescribed for typical soJIA. She underwent surgical debridement removal, and several courses of antibiotics proved ineffective. She developed macrophage activation syndrome, following which anakinra was prescribed, which resulted in only temporary improvement. Therefore, this drug was switched to canakinumab, which caused corticosteroid-free remission.

Conclusion

This is the first description of a rare association of soJIA with inflammatory bone lesions with the proven efficacy of IL-1 blockade. The association of two autoinflammatory conditions should indicate IL-1-driven mechanisms and a possible genetic basis. Follow-up genetic and functional studies are required to better understand the pathogenesis of such overlapping diseases.

Bisphosphonate-treatment of secondary chronic osteomyelitis of the jaw - a case report

Secondary chronic osteomyelitis (SCO) is caused by bacterial infection leading to progressive jawbone destruction. Antibiotics are used as first-line treatment; surgical therapy is usually extensive and may not provide a cure. Bisphosphonates have been reported to be successful in patients with primary nonbacterial osteomyelitis, and literature indicates promising results in SCO. A 38-year-old patient presented with a progressive mandible-destruction 17 years after wisdom tooth extraction. Several treatment attempts have been unsuccessful. Seeking a second opinion, the patient was then interdisciplinary treated with 90 mg of intravenous pamidronate every four weeks, three times. The patient did not experience side effects presenting a considerable improvement in mouth opening and reporting a dissolvent of signs of pain or infection. The MRI showed edema reduction and decreased contrast uptake. Therefore, bisphosphonate treatment of secondary chronic osteomyelitis of the jaw is a safe and effective option in selected cases after unsuccessful first- and second-line therapy.

Gathering expert consensus to inform a proposed trial in chronic nonbacterial osteomyelitis (CNO)

Chronic nonbacterial osteomyelitis (CNO) is an autoinflammatory bone disease that primarily affects children and adolescents. CNO is associated with pain, bone swelling, deformity, and fractures. Its pathophysiology is characterized by increased inflammasome assembly and imbalanced expression of cytokines. Treatment is currently based on personal experience, case series and resulting expert recommendations. Randomized controlled trials (RCTs) have not been initiated because of the rarity of CNO, expired patent protection of some medications, and the absence of agreed outcome measures. An international group of fourteen CNO experts and two patient/parent representatives was assembled to generate consensus to inform and conduct future RCTs. The exercise delivered consensus inclusion and exclusion criteria, patent protected (excludes TNF inhibitors) treatments of immediate interest (biological DMARDs targeting IL-1 and IL-17), primary (improvement of pain; physician global assessment) and secondary endpoints (improved MRI; improved PedCNO score which includes physician and patient global scores) for future RCTs in CNO.

Diagnosis and Treatment of Chronic Non-bacterial Osteomyelitis: A Survey on Current Practices Adopted by Pediatric Rheumatologists in Saudi Arabia

INTRODUCTION

Chronic nonbacterial osteomyelitis (CNO) is an autoinflammatory bone disease usually managed by pediatric rheumatologists (PRs). There is a need for a consensus treatment plan to minimize the diversity in clinical practice in the diagnosis and management of CNO. In this study, we explored the practice of PRs in Saudi Arabia on the diagnosis and treatment of patients with CNO.

METHODS

This is a cross-sectional study that was conducted among PRs in Saudi Arabia (May to September 2020). A survey was performed among PRs registered in the Saudi Commission for Health Specialties using an electronic-based questionnaire. The survey consisted of 35 closed-ended questions about the diagnosis and management of CNO patients. We explored the approaches adopted by PRs in diagnosing and monitoring the disease activity, their awareness of clinical possibilities that necessitate ordering bone biopsy, and the treatment choices they considered for CNO patients.

RESULTS

We scrutinized data from a total of 77% (n=41/53) PRs who responded to our survey. Magnetic resonance imaging (MRI) was reported as the most frequently used modality in suspected CNO (82%, n=27/33), followed by plain X-ray (61%) and bone scintigraphy (58%). Magnetic resonance imaging of a symptomatic site is the imaging modality of choice for the diagnosis of CNO (82%), Followed by X-ray (61%) and bone scintigraphy (58%). The reasons for performing bone biopsy were unifocal lesions (82%), unusual sites of presentation (79%), and multifocal lesions (30%). The preferred treatment regimens were bisphosphonates (53%), non-steroidal anti-inflammatory drugs alone (43%), or biologics with bisphosphonates (28%). The reasons to upgrade the treatment in CNO included the development of vertebral lesions (91%), the development of new lesions in MRI (73%), and the elevation of inflammatory markers (55%). The disease activity was assessed by history and physical examination (91%), inflammatory markers (84%), MRI of targeted symptomatic site (66%), and a whole-body MRI (41%).

CONCLUSIONS

The approach to diagnosis and treatment of CNO varies among PRs in Saudi Arabia. Our findings provide a background for the development of a consensus treatment plan for challenging CNO patients.

Chronic Nonbacterial Osteomyelitis and Inflammatory Bowel Disease: A Literature Review-Based Cohort

Background: Chronic nonbacterial osteomyelitis (CNO) is a rare autoinflammatory bone disorder that mainly involves children and adolescents. The association with other inflammatory disorders, such as inflammatory bowel disease (IBD), psoriasis, and arthritis, has been reported in the literature. In particular, the relationship between bone and intestinal inflammation is still poorly understood. For this purpose, our review aims to describe the cases reported in the literature concerning this association and to compare them with data from our single-center cohort of patients. Methods: We conducted a literature review of published cases of CNO associated with IBD. Eligible articles were identified through a Medline search in the PubMed database until December 2022. We retrospectively reviewed medical records of patients with CNO referred to G. Pini Hospital and compared them with the literature-review-based cohort. Results: Fifty-seven patients with a defined diagnosis of CNO and associated IBD were described in the literature (female 55%). The median age of onset of the disease (CNO or IBD) was 11 years. In 32/53 (60%), a diagnosis of Crohn’s disease (CD) was made, while 18 (34%) patients were classified as suffering from ulcerative colitis (UC) and 3 (6%) from undifferentiated IBD. The diagnosis of CNO preceded the diagnosis of IBD in 59% of cases; while in 24%, IBD anticipated CNO; and in 17%, the two conditions appeared simultaneously. The median time between the two events was 24 months. In our Italian cohort (n = 23 patients), no diagnosis of IBD was made. No significant differences were found when comparing clinical and demographical characteristics of the Italian vs. review-based cohort, except for a significant involvement of rachis in the Italian group. Conclusions: The correlation between autoinflammatory bone disease and intestinal inflammation should be further investigated. It is essential to promote awareness among pediatric rheumatologists and gastroenterologists about this possible association to facilitate the diagnosis and better optimize treatment.

Chronic recurrent multifocal osteomyelitis: A multidisciplinary experience of 22 pediatric cases with a mean follow-up of 27 months

BACKGROUND

Chronic recurrent multifocal osteomyelitis (CRMO) is not a well known disorder among nonpediatricians. The aim of this study is to retrospectively evaluate the clinical outcomes of twenty-two CRMO patients presenting to two referral centres.

METHODS

This retrospective study included twenty-two children (12 males, 10 females; mean age 13 years; range 7-17 years). The diagnosis was based on clinical, radiological, and pathological findings. Data were retrieved from hospital charts.

RESULTS

The mean delay in diagnosis was 26 months (range, 0-96 months). The mean follow-up after diagnosis was 27.4 months (range, 6-47 months). Symptoms included pain, limping, local swelling, morning stiffness, and fever. 18 patients had multifocal and 4 patients had unifocal disease. Bone lesions were detected with whole-body or local MRI (Magnetic Resonance Imaging). The mean number of bone lesions was 2.5 (range, 1-8). Ten cases underwent biopsy to exclude malignancy and infection. Prior to diagnosis, cast immobilization or curettage was erroneously performed in four patients. One patient suffered from vertebral compression fracture. There is no growth disturbance or deformity in any patient.

CONCLUSION

This study demonstrated that early recognition of the disease can be improved by using Bristol criteria which should be evaluated by a multidisciplinary team rather than one single specialist. In this way, the reliability of these criteria is improved and the treatment could be given earlier with decreased delay in diagnosis. This multidisciplinary approach is also important for decision for biopsy, timely aggressive medical treatment, and follow-up of the disease to minimise possible complications.

Clinical characteristics and predictors for recurrence in chronic nonbacterial osteomyelitis: a retrospective multicenter analysis

Background/aim

Chronic nonbacterial osteomyelitis (CNO) is a rare disease of unknown etiology and most commonly occurs during childhood or adolescence. The purpose of this study is to collect data on the clinical features, outcomes, and management of the disease and to identify the factors affecting recurrence.

Materials and methods

This is a retrospective multicenter cross-sectional study of pediatric patients diagnosed with CNO. A total of 87 patients with a diagnosis of CNO followed for at least 6 months in 8 pediatric rheumatology centers across the country between January 2010 and December 2021 were included in this study.

Results

The study included 87 patients (38 girls, 49 boys; median age: 12.5 years). The median follow-up time was 20 months (IQR: 8.5-40). The median time of diagnostic delay was 9.9 months (IQR: 3-24). Arthralgia and bone pain were the most common presenting symptoms. Multifocal involvement was detected in 86.2% of the cases and a recurrent course was reported in one-third of those included in the study. The most commonly involved bones were the femur and tibia. Vertebrae and clavicles were affected in 19.5% and 20.6% of cases, respectively. The erythrocyte sedimentation rate (ESR) values of 60.9% of the patients were above 20 mm/h and the C-reactive protein values of 44.8% were above 5 mg/L. The remission rate was 13.3% in patients using nonsteroidal antiinflammatory drugs and 75.0% in those using biological drugs. Vertebral and mandibular involvement and high ESR values at the time of diagnosis were associated with recurrence.

Conclusion

In this multicenter study, CNO with vertebral and mandibular involvement and high ESR at diagnosis were associated with recurrence.

A Successful Bisphosphonates Monotherapy in Spinal Form of Paediatric Chronic Recurrent Multifocal Osteomyelitis (CRMO)—Case Report

Chronic recurrent multifocal osteomyelitis (CRMO) is a non-infectious inflammatory disorder resulting from the multifocal bone and bone marrow lesions with periodic relapses and remissions and with an uncertain prognosis. Treatment options in CRMO are based on expert opinion and relatively small groups of patients. A nine-year-old female patient with no significant past medical history presented with compression fractures and multifocal bone lesions in the thoracic and lumbar spine, as shown in imaging (CT, MRI). Densitometry revealed a diffuse decrease in bone density. Based on the patient’s clinical image and above examinations, the other possible aetiologies—infectious (including tuberculosis), neoplasms, Langerhans cell histiocytosis—were ruled out, which led to eventual final diagnosis—CRMO. The patient was successfully treated with pamidronate infusion initiated in cycles over three consecutive days every 3 months. In addition to clinical improvement, there was a significant remission of inflammation and bone structure healing assessed by MRI after four treatment cycles. Intravenous bisphosphonates usage seems to be a good therapeutic option in CRMO paediatric patients with spinal localization of the lesions complicated by compressive fractures. However, more data, based on larger patient populations, are needed to provide a detailed paediatric CRMO treatment algorithm.

How Have the Diagnosis and Treatment of Chronic Recurrent Multifocal Osteomyelitis Changed Over Time?

PURPOSE

Chronic recurrent multifocal osteomyelitis (CRMO) is a rare inflammatory condition characterized by sterile bone lesions. There appears to be a shift in the diagnostic modalities and treatment over the past decades despite insufficient published data. The purpose of this study was to document: 1) the number of patients diagnosed with CRMO, 2) patient demographics, 3) disease characteristics at presentation, 4) diagnostic modalities employed, and 5) treatments prescribed at our institution over a 30-year period.

METHODS

This single-center, retrospective cohort study included children diagnosed with CRMO who presented between 1990 and 2020. The electronic medical records were queried using numerous search terms. Patients were excluded if CRMO was included in the differential diagnosis but was not confirmed at the time of chart review or if CRMO was suspected early in the disease course but the patient was ultimately diagnosed with another condition. The predictor (time in years) and outcome variables (diagnostic modalities and treatment types) were tested using bivariate analyses using IBM SPSS, Version 27 (IBM Corp., Armonk, NY).

RESULTS

A total of 224 patients were diagnosed with CRMO during the observation period (68.3% female; 67.4% white). The number of patients diagnosed over the past decade rose by 215%, as compared to the previous 2 decades (1990 to 2010). Regional magnetic resonance imaging (83.8%) and biopsy (66.5%) were the most utilized diagnostic modalities over the past decade, with a statistically significant decline in the proportion of biopsies performed (66.5% during the past decade vs 84.9% in the previous 2 decades, P = .01). Over the past decade, nonsteroidal anti-inflammatory drugs (40.1%), disease-modifying antirheumatic drugs (27.1%), and tumor necrosis factor inhibitors (21.1%) were the most commonly used treatments, with a statistically disproportionate increase in the use of tumor necrosis factor inhibitors (21.1% during the past decade vs 3.8% in the previous 2 decades, P < .001).

CONCLUSIONS

This is one of the largest CRMO cohort studies and the only study to observe changes in diagnostic modalities and treatment over a 30-year period. Future studies should assess the impact of variations in clinical presentation, time to diagnosis, diagnostic modalities, and management as predictors of disease outcomes.

Neurosurgical management of vertebral lesions in pediatric chronic recurrent multifocal osteomyelitis: patient series

BACKGROUND

Chronic recurrent multifocal osteomyelitis (CRMO) is a rare pediatric autoinflammatory disorder involving 2 or more inflammatory bone lesions separated in time and space associated with pathological vertebral fractures. There are no current guidelines for the role of pediatric spine surgeons in the management of this condition. The authors demonstrate the importance of close and early involvement of neurosurgeons in caring for patients with CRMO with vertebral involvement.

OBSERVATIONS

Fifty-six pediatric patients with clinical and radiographic evidence of CRMO were identified and clinical, radiographic, laboratory, and histopathological data were reviewed. All were evaluated via Jansson and Bristol CRMO diagnostic criteria. Ten had radiographic evidence of vertebral involvement (17.9%). Nine of these had multifocal disease. Five patients had multiple vertebrae affected. Six patients were evaluated for possible surgical intervention and one required intervention due to vertebra plana leading to a progressive kyphotic deformity and significant spinal canal stenosis.

LESSONS

In conjunction with management by the primary pediatric rheumatology team using nonsteroidal anti-inflammatory drugs, disease-modifying anti-rheumatic drugs, immunotherapies, and bisphosphonates, given the risk of pathological fractures and potential resulting long-term neurological deficits, the authors recommend close monitoring and management by pediatric spine surgeons for any patient with CRMO with vertebral lesions.

Bell's palsy with facial bone involvement: A rare presentation of chronic nonbacterial osteomyelitis with literature review

Chronic nonbacterial osteomyelitis (CNO) is a chronic, sterile, inflammatory disease. It primarily presents with nonspecific bone pain and swelling but ultimately can cause bone destruction and deformities, if left untreated. The involvement of the cranial bones (apart from the mandible) is rare in CNO. In this report, we present a rare case of CNO affecting facial and cranial bones presenting as facial palsy with a review of the literature about similar affection. A 10-year-old, previously healthy female was initially evaluated for swelling of the left side of her face with slight tenderness on palpation, but no fever. Her complete blood count was unremarkable, her inflammatory markers were elevated (C-reactive protein 7.5 mg/dl and erythrocyte sedimentation rate 104 mm/h), and CT of facial and skull bones and MRI of brain showed a destructive osseous process involving the left maxillary, zygomatic, sphenoid bones and the clivus. Bone biopsy of the left maxilla showed fibrous dysplasia with abscess formation, most consistent with an infectious aetiology (acute osteomyelitis). She was started on oral clindamycin for a 3-month course. The facial swelling improved after starting clindamycin, but on her sixth week of treatment, she developed right-sided Bell's palsy. An MRI of the brain showed hyperenhancement of the right seventh cranial nerve. A month later, she was evaluated for right wrist and knee swelling, pain, and limitation of movement. Skeletal survey and MRI showed multifocal lesions with mixed sclerosis and lucency. Her inflammatory markers continued to be elevated. Another bone biopsy of the right radius showed similar findings of destruction with no evidence of malignancy. She was ultimately diagnosed with CNO. She was started on nonsteroidal anti-inflammatory drugs with gastric protection and regular follow-up. Over more than a year of follow-up, the patient's inflammatory markers remain normal, and joint swelling/limitation has remained in remission. We found five additional cases in the literature that presented with a similar presentation. To our knowledge, our patient is the first reported case in the USA involving the cranial/facial bones apart from the mandible presenting with facial palsy. The affection of the facial bones (apart from the mandible) in CNO is very rare, but the awareness of such a presentation by the clinician is an important aspect of reaching the diagnosis.

Colchicine as rescue treatment in two pediatric patients with chronic recurrent multifocal osteomyelitis (CRMO)

Chronic recurrent multifocal osteomyelitis (CRMO) is a rare idiopathic autoinflammatory bone disease characterised by noninfective inflammation of bones. Diagnostic approach is challenging and requires exclusion of other causes such as malignancies or infections. Nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids are usually applied as first-line therapy in CRMO patients; however, some cases require more intensive therapy with second-line agents to control disease activity. We hereby describe the use of colchicine as a nonconventional second-line disease-modifying antirheumatic drug in two pediatric patients with CRMO refractory to NSAIDs and corticosteroids. Our data indicate that colchicine might prove an important area for future research as a potential therapeutic option with easy administration, low cost, and a good safety profile in CRMO patients refractory to first-line therapy.

Case report: Child chronic nonbacterial osteomyelitis with rapid progressive scoliosis-an association with disease?

Background

Chronic nonbacterial osteomyelitis (CNO) is an auto-inflammatory bone disease that usually develops in childhood. Spinal involvement is a common manifestation of CNO, but it is rare for CNO to lead to rapid progression of scoliosis deformity. Here we present a 9-year-old girl with acute scoliosis with CNO and scoliosis progressed rapidly in 2 months.

Case Presentation

A 9-year-old girl presented bilateral shoulder inequality with pain in the left hypochondrium for 2 months. Standing spinal x-rays showed right convex scoliosis with a 25° Cobb angle. Chest magnetic resonance imaging (MRI) showed that the T8 vertebra was flattened and local bone was destroyed with bone marrow edema. The bone biopsy showed evidence of fibrosis and chronic inflammatory changes with no specific diagnosis. One month later, her scoliosis and bone destruction deteriorated obviously. Thoracic vertebra MRI showed that the T8 vertebra had a compression fracture. ^99mTc-MDP whole-body bone scintigraphy showed intense uptake at T8/9 and the right sacroiliac joint. She was diagnosed with CNO accompanied by rapidly progressive scoliosis. The scoliosis was successfully treated with adalimumab and zoledronic acid, which showed significant improvement after 6 months of follow-up.

Conclusion

Zoledronic acid and adalimumab successfully treated CNO with rapidly progressive scoliosis, but could not prevent vertebral compression.

Two phenotypes of chronic recurrent multifocal osteomyelitis with different patterns of bone involvement

INTRODUCTION

Chronic Recurrent Multifocal Osteomyelitis (CRMO) is an autoinflammatory bone disorder with predominantly paediatric onset. Children present with multifocal osteolytic lesions accompanied by bone pain and soft tissue swelling. Patients often exhibit extraosseous co-morbidities such as psoriasis, inflammatory bowel disease, and arthritis.

OBJECTIVES

Comparison of children with two different phenotypes of CRMO defined by presence or absence of extraosseous co-morbidities.

METHODS

Children diagnosed with CRMO at the Motol University Hospital between 2010 and 2020 were retrospectively reviewed, and according to the absence or presence of extraosseous manifestations divided into two cohorts - bone limited CRMO and complex CRMO. The two groups were compared in terms of demographic data, age at disease onset, number and site of bone lesions, laboratory biomarker values, and need of escalation to a second-line therapy.

RESULTS

Thirty-seven children (30 female, 7 male) with confirmed CRMO were included in the analysis. The mean age at disease onset was 10 years. All but 3 patients presented with multifocal disease. Twenty-three children (62%) had at least one extraosseous manifestation (13 sacroiliitis, 8 inflammatory bowel disease, 6 skin disease [acne, pustulosis, or psoriasis], 7 arthritis). Complex CRMO was associated with a significantly higher ESR rate (p = 0.0064) and CRP level (p = 0.018). The groups did not differ in number of foci or in age at disease onset. Bone lesion distribution differed between the two groups with significantly more frequent involvement of clavicle (p = 0.011) and pelvis (p = 0.038) in patients with complex CRMO. Children with complex CRMO more often needed escalation of therapy to DMARDs and biologic agents.

CONCLUSION

Our data suggest that CRMO affecting solely the skeleton has milder course compared to complex CRMO with extraskeletal features. Further studies are needed to explore the clinical as well as the patient reported outcomes and promote individually tailored therapeutic strategies in both CRMO phenotypes.

Whole-body MRI at initial presentation of pediatric chronic recurrent multifocal osteomyelitis and correlation with clinical assessment

BACKGROUND

Chronic recurrent multifocal osteomyelitis (CRMO) is a diagnosis of exclusion, relying heavily on whole-body magnetic resonance imaging (WB-MRI) for diagnosing and evaluating response to therapy. Information with respect to disease distribution and imaging correlation with clinical disease severity at initial presentation is lacking.

OBJECTIVE

To retrospectively characterize distribution of disease on WB-MRI and to correlate imaging findings with disease severity at initial rheumatology presentation.

MATERIALS AND METHODS

Using a modified version of a recently devised imaging-based scoring system, we evaluated disease distribution and correlation between findings on WB-MRI and clinical disease severity in 54 patients presenting for initial evaluation of CRMO. Symptomatic lesion sites were extracted from chart review and physician global assessment was determined by the consensus of two rheumatologists.

RESULTS

Sites of CRMO involvement evident on imaging at initial presentation had a strong predilection for the pelvis and lower extremities. There was significant correlation between the number of lesions detected on WB-MRI and total clinical severity score at initial rheumatology presentation (P&lt;0.01). However, no other imaging parameter correlated with disease severity.

CONCLUSION

While the overall number of lesions identified on MRI correlates with clinical severity scores at initial imaging, other MR parameters of CRMO lesions may not be reliable indicators of disease severity at initial presentation. Further research is needed to assess whether these parameters are implicated in longitudinal disease severity or overall response to therapy.

Chronic Recurrent Multifocal Osteomyelitis (CRMO): A Study of 12 Cases from One Institution and Literature Review

BACKGROUND

CRMO is a sterile auto inflammatory bone disease that affects the pediatric population. Recently, single gene mutations in LPIN2, DIRA, and IL1RN have been reported in murine models of CRMO.

MATERIALS AND METHODS

The medical records and histopathological slides of twelve patients were reviewed.

RESULTS

The diagnosis was determined by multiple lesions, imaging, negative cultures, bone biopsy, and lack of antibiotic response. Biopsy showed early neutrophilic infiltrates, and older lesions showed lymphoplasmacytic infiltrates and fibrosis. Patients were treated with anti-inflammatory medication with some lesions completely resolving.

CONCLUSION

Bone biopsy aids the diagnosis of CRMO in correlation with clinical presentation, imaging, and culture findings. Our findings indicate the kinetics of CRMO is not well defined and the fibrosis may be reached after months, in contrast to the previously reported several years. We hope that these genetic mutations can be further studied in human models to describe the genetics behind CRMO.

Chronic nonbacterial osteomyelitis: the role of whole-body MRI

Background

Chronic nonbacterial osteomyelitis (CNO), also known as chronic recurrent multifocal osteomyelitis, is a noninfectious autoinflammatory disorder that occurs primarily in children and adolescents and is characterized by episodic musculoskeletal pain with a protracted course.

Main body

Traditionally, the diagnosis of CNO is made by exclusion and commonly requires bone biopsy to rule out infection and malignancy. However, bone biopsy may be avoided when imaging and clinical characteristic features are present, such as multifocal bone lesions at typical sites, no constitutional symptoms and no signs of infection in laboratory test results. Whole-body magnetic resonance imaging (WB-MRI) can assess signs of acute and chronic inflammation and enables the detection of CNO typical patterns of lesion location and distribution, thereby helping to exclude differential diagnosis. The goal of the present study paper is to review the main clinical and imaging aspects of the disease with emphasis on the role of WB-MRI in the diagnosis, assessment of disease burden and follow-up monitoring.

Conclusion

Radiologists need to be familiar with the imaging features to suggest the diagnosis as the early therapy may help to avoid irreversible secondary damage of skeletal system.

New insights on multigenic autoinflammatory diseases

Autoinflammatory diseases are disorders of the innate immune system, which can be either monogenic due to a specific genetic mutation or complex multigenic due to the involvement of multiple genes. The aim of this review is to explore and summarize the recent advances in pathogenesis, diagnosis, and management of genetically complex autoinflammatory diseases, such as Schnitzler's syndrome; adult-onset Still's disease; synovitis, acne, pustulosis, hyperostosis, osteitis syndrome/chronic recurrent multifocal osteomyelitis/chronic non-bacterial osteomyelitis; Adamantiades-Behçet's disease; Yao syndrome; and periodic fever with aphthous stomatitis, pharyngitis, and adenitis syndrome. The PubMed database was screened for relevant articles using free text words and specific search strings. The search was limited to English-language articles, reporting the results of studies in humans, published through March 2021. Evidence from literature suggest that these rare multigenic autoinflammatory diseases can present with different clinical features and the diagnosis of these diseases can be challenging due to a combination of nonspecific manifestations that can be seen in a variety of other conditions. Diagnostic delays and disease complications may occur due to low disease awareness and the lack of pathognomonic markers. The pathogeneses of these diseases are complex and in some cases precise pathogenesis is not clearly understood. Conventional treatments are commonly used for the management of these conditions, but biologics have shown promising results. Biologics targeting proinflammatory cytokines including IL-1, IL-6, TNF-α, IL-17A and IL-18 have been shown to ameliorate signs and symptoms of different multigenic autoinflammatory diseases.

Pediatric rheumatologists' perspectives on diagnosis, treatment, and outcomes of Sjögren disease in children and adolescents

BACKGROUND

Sjögren disease in children and adolescents (pedSD) presents differently than adult disease. Diagnosis and classification are controversial, optimal treatment is unknown and outcomes are poorly understood. Here, we describe the current perspectives of pediatric rheumatologists on diagnosis, treatment, and outcomes of pedSD.

METHODS

A voluntary, 17-question survey was distributed to providers in the Childhood Arthritis and Rheumatology Research Alliance and/or the American College of Rheumatology Childhood Sjögren's Study Group at the 2020 Convergence Virtual Conference. Findings are reported using descriptive statistics and chi-square testing.

RESULTS

Of 465 eligible providers, 157 (34%) responded with 135 (29%) completing the survey. The majority (85%) saw five or fewer patients with pedSD in the past year. Parotitis, dry eye and/or dry mouth, and constitutional symptoms were among the most specific and common clinical features. Most providers (77%) used clinical judgment guided by adult criteria for diagnosis. The vast majority (86-99%) of survey participants indicated routine use of serologic testing, while salivary gland ultrasound, minor salivary gland biopsy and other diagnostic tests were less often used. The most commonly prescribed systemic immunomodulators were hydroxychloroquine, corticosteroids, methotrexate, rituximab, and mycophenolate. Seven providers reported malignancy in a patient with pedSD, including one death.

CONCLUSIONS

Pediatric rheumatologists diagnose and treat pedSD; however, most only see a few patients per year and rely on clinical judgment and laboratory testing for diagnosis. Treatment frequently includes systemic immunomodulators and malignancies are reported. More studies are needed to better understand natural history, risk factors, and the impact of interventions on outcomes.