Predictive plain X-ray findings in distinguishing early stage acute lymphoblastic leukemia from juvenile idiopathic arthritis

A clinical perspective on imaging in juvenile idiopathic arthritis

In recent years, imaging has become increasingly important to confirm diagnosis, monitor disease activity, and predict disease course and outcome in children with juvenile idiopathic arthritis (JIA). Over the past few decades, great efforts have been made to improve the quality of diagnostic imaging and to reach a consensus on which methods and scoring systems to use. However, there are still some critical issues, and the diagnosis, course, and management of JIA are closely related to clinical assessment. This review discusses the main indications for conventional radiography (XR), musculoskeletal ultrasound (US), and magnetic resonance imaging (MRI), while trying to maintain a clinical perspective. The diagnostic-therapeutic timing at which one or the other method should be used, depending on the disease/patient phenotype, will be assessed, considering the main advantages and disadvantages of each imaging modality according to the currently available literature. Some brief clinical case scenarios on the most frequently and severely involved joints in JIA are also presented.

M-ficolin: a valuable biomarker to identify leukaemia from juvenile idiopathic arthritis

OBJECTIVE

Distinction on clinical grounds between acute lymphoblastic leukaemia presenting with arthropathy (ALLarthropathy) and juvenile idiopathic arthritis (JIA) is difficult, as the clinical and paraclinical signs of leukaemia may be vague. The primary aim was to examine the use of lectin complement pathway proteins as markers to differentiate ALLarthropathy from JIA. The secondary aims were to compare the protein levels at baseline and follow-up in a paired number of children with ALL and to examine the correlation with haematology counts, erythrocyte sedimentation reaction (ESR), C-reactive protein (CRP), blasts, relapse and death.

STUDY DESIGN

In this observational study, we measured M-ficolin, CL-K1 and MASP-3 in serum from children with ALL (n=151) and JIA (n=238) by time-resolved immunofluorometric assays. Logistic regression was used for predictions of ALL risk, considering the markers as the respective exposures. We performed internal validation using repeated '10-fold cross-validation' with 100 repetitions computing the area under the curve (AUC) as well as positive and negative predictive values in order to evaluate the predictive performance.

RESULTS

The level of M-ficolin was higher in JIA than ALLtotal and the ALLarthropathy subgroup. The M-ficolin level normalised after remission of ALL. M-ficolin could differentiate ALL from JIA with an AUC of 94% and positive predictive value (PPV) of 95%, exceeding CRP and haemoglobin. In a dichotomised predictive model with optimal cut-offs for M-ficolin, platelets and haemoglobin, AUC was 99% and PPV 98% in detecting ALL from JIA.

CONCLUSION

M-ficolin is a valuable marker to differentiate the child with ALL from JIA.

Utility of emergent plain X-ray for childhood acute leukemia with bone pain

BACKGROUND

We aimed to evaluate the utility of plain X-ray radiograph (PXR) findings in suggesting a diagnosis of acute leukemia in children presenting with bone pain in the emergency department (ED) of a children's hospital.

METHODS

Using our radiology reporting system and registered data for childhood acute leukemia, we collected data regarding patients who underwent musculoskeletal PXR examinations in the ED due to bone pain in their extremities, from March 1, 2002 to June 30, 2015. We retrospectively reviewed their PXR findings and clinical information from the electronic medical records.

RESULTS

A total of 1,331 patients underwent PXR examinations and in 12 PXR findings showed suspected acute leukemia. From the registered data we found 12 acute leukemia patients who underwent emergency extremity PXR. Ten patients were finally confirmed to have acute leukemia by bone marrow examinations. The most common finding was lucent metaphyseal bands, demonstrated in seven cases, whereas six patients did not show any abnormalities in their peripheral blood cell counts. Sensitivity and specificity values of PXR for acute leukemia diagnosis were 90.0% and 99.8%, respectively. Positive predictive value and negative predictive values were 75.0% and 99.9%, respectively.

CONCLUSIONS

Plain X-ray radiograph is a useful diagnostic tool to detect possible acute leukemia in patients presenting with bone pain, earlier than abnormalities of their peripheral blood cell counts. Our results implied the possibility of re-examining PXRs in acute leukemia more carefully, even when there are no abnormalities in blood cell counts.

Uncommon Presentation of Childhood Leukemia in Emergency Department: The Usefulness of an Early Multidisciplinary Approach

ABSTRACT

Leukemia is the most common childhood malignancy, and it is often characterized by pallor, fatigue, cytopenia, and organomegaly; sometimes musculoskeletal symptoms, mainly characterized by diffuse bone pain in the lower extremities, are the onset clinical characteristics of the disease. In these cases, the disease may initially be misdiagnosed as reactive arthritis, osteomyelitis, or juvenile idiopathic arthritis delaying appropriate diagnosis and management. Even if leukopenia, thrombocytopenia, and a history of nighttime pain are reported to be the most important predictive factors for a pediatric leukemia, blood examinations can sometimes be subtle or within normal limits, and this represents a further diagnostic difficulty. Radiological findings of leukemic bone involvement are described in patients with musculoskeletal symptoms of acute lymphoblastic leukemia and often appear before hematologic anomalies, but they are not specific for the disease. However, they could be helpful to get the right diagnosis if integrated with other features; thus, it is important knowing them, and it is mandatory for the multidisciplinary comparison to talk about dubious cases even in an emergency setting. We describe 4 patients visited in the emergency department for musculoskeletal complaints and having radiological lesions and a final diagnosis of acute lymphoblastic leukemia, in whom the onset of the manifestations could mimic orthopedic/rheumatologic diseases.

Identifying acute lymphoblastic leukemia mimicking juvenile idiopathic arthritis in children

Objective

Acute lymphoblastic leukemia (ALL) may present with arthritis implying the risk of being misdiagnosed as juvenile idiopathic arthritis (JIA). The aim of this study was to identify predictors for ALL based on clinical and laboratory information.

Methods

This cross-sectional, retrospective study compared clinical presentation and laboratory results of 26 children with ALL and arthritis versus 485 children with JIA (433 non-systemic, 52 systemic JIA). Using a Bayesian score approach the findings were evaluated by calculating odds ratios (OR) and lnOR as a measure of diagnostic weight.

Results

Distinction on clinical grounds was difficult, as even a high number of joints involved did not exclude ALL. One or more hematologic cell counts were low (Hb <10 g/dL, platelet count <100 x 10⁹/L, neutrophil count < 1.0 x 10⁹/L) in 92% with ALL, 25% with systemic JIA and 10% with non-systemic JIA. Neutropenia and thrombocytopenia had the highest ORs of 128 (95% CI 43–387) and 129 (95% CI 26–638), each giving a diagnostic weight of 4. The estimated risks of ALL were 0.2% with normal cell counts and 9%, 67% and 100% when one, two or three cell lines were affected.

Conclusion

A simple count of cell lines with low counts can serve as a basic diagnostic strategy. Children with tri- or bilinear involvement should be referred to a bone marrow, and those with unilinear involvement a thorough screen for further evidence of ALL (organomegaly, ESR, LDH, uric acid, and blood smear).

Acute Leukemia Presenting with Musculoskeletal Manifestations: A Case Series

Introduction: Leukemia is the most common childhood malignancy accounting for 30%–40% of cases. Acute lymphoblastic leukemia is the most common leukemia in children with peak incidence in 2–6 years of age. The present study aims to assess the incidence of acute leukemia in patients presenting with musculoskeletal manifestations. Materials and Methods: This is a retrospective study conducted in a tertiary center from January 2014 to December 2018. A total of 63 children presented with musculoskeletal manifestations and underwent bone marrow examination. Based on final marrow diagnosis, the study group was divided into leukemic and nonleukemic groups. Results: Fever was the most common presenting complaint and was present in all the patients of both the groups. The occurrence of hepatosplenomegaly was comparatively higher in the leukemic group than in patients with juvenile idiopathic arthritis (JIA). The predominant type of arthritis was oligoarticular (68.15%) in the leukemic group and polyarticular (77.27%) in the nonleukemic group. Rheumatoid rash was noted in 20% of JIA patients, and none of the patients in the leukemic group had rash. The percentages of anemia, leukopenia, and thrombocytopenia were statistically higher in leukemia patients than in JIA patients. Conclusion: Bone marrow studies are a prerequisite in diagnosing leukemias. However, based on the presence of few atypical clinical and laboratory features, leukemia can be excluded in JIA patients.

Conventional radiography in juvenile idiopathic arthritis: Joint recommendations from the French societies for rheumatology, radiology and paediatric rheumatology

BACKGROUND

Juvenile idiopathic arthritis (JIA) can cause structural damage. However, data on conventional radiography (CR) in JIA are scant.

OBJECTIVE

To provide pragmatic guidelines on CR in each non-systemic JIA subtype.

METHODS

A multidisciplinary task force of 16 French experts (rheumatologists, paediatricians, radiologists and one patient representative) formulated research questions on CR assessments in each non-systemic JIA subtype. A systematic literature review was conducted to identify studies providing detailed information on structural joint damage. Recommendations, based on the evidence found, were evaluated using two Delphi rounds and a review by an independent committee.

RESULTS

74 original articles were included. The task force developed four principles and 31 recommendations with grades ranging from B to D. The experts felt strongly that patients should be selected for CR based on the risk of structural damage, with routine CR of the hands and feet in rheumatoid factor-positive polyarticular JIA but not in oligoarticular non-extensive JIA.

CONCLUSION

These first pragmatic recommendations on CR in JIA rely chiefly on expert opinion, given the dearth of scientific evidence. CR deserves to be viewed as a valuable tool in many situations in patients with JIA.

KEY POINTS

• CR is a valuable imaging technique in selected indications. • CR is routinely recommended for peripheral joints, when damage risk is high. • CR is recommended according to the damage risk, depending on JIA subtype. • CR is not the first-line technique for imaging of the axial skeleton.

A new autoinflammatory and autoimmune syndrome associated with NLRP1 mutations: NAIAD (NLRP1-associated autoinflammation with arthritis and dyskeratosis)

OBJECTIVES

Inflammasomes are multiprotein complexes that sense pathogens and trigger biological mechanisms to control infection. Nucleotide-binding oligomerisation domain-like receptor (NLR) containing a PYRIN domain 1 (NLRP1), NLRP3 and NLRC4 plays a key role in this innate immune system by directly assembling in inflammasomes and regulating inflammation. Mutations in NLRP3 and NLRC4 are linked to hereditary autoinflammatory diseases, whereas polymorphisms in NLRP1 are associated with autoimmune disorders such as vitiligo and rheumatoid arthritis. Whether human NLRP1 mutation is associated with autoinflammation remains to be determined.

METHODS

To search for novel genes involved in systemic juvenile idiopathic arthritis, we performed homozygosity mapping and exome sequencing to identify causative genes. Immunoassays were performed with blood samples from patients.

RESULTS

We identified a novel disease in three patients from two unrelated families presenting diffuse skin dyskeratosis, autoinflammation, autoimmunity, arthritis and high transitional B-cell level. Molecular screening revealed a non-synonymous homozygous mutation in NLRP1 (c.2176C>T; p.Arg726Trp) in two cousins born of related parents originating from Algeria and a de novo heterozygous mutation (c.3641C>G, p.Pro1214Arg) in a girl of Dutch origin. The three patients showed elevated systemic levels of caspase-1 and interleukin 18, which suggested involvement of NLRP1 inflammasome.

CONCLUSIONS

We demonstrate the responsibility of human NLRP1 in a novel autoinflammatory disorder that we propose to call NAIAD for NLRP1-associated autoinflammation with arthritis and dyskeratosis. This disease could be a novel autoimmuno-inflammatory disease combining autoinflammatory and autoimmune features. Our data, combined with that in the literature, highlight the pleomorphic role of NLRP1 in inflammation and immunity.

TRIAL REGISTRATION NUMBER

NCT02067962; Results.

Musculoskeletal Imaging Findings of Hematologic Malignancies

Hematologic malignancies comprise a set of prevalent yet clinically diverse diseases that can affect every organ system. Because blood components originate in bone marrow, it is no surprise that bone marrow is a common location for both primary and metastatic hematologic neoplasms. Findings of hematologic malignancy can be seen with most imaging modalities including radiography, computed tomography (CT), technetium 99m (^99mTc) methylene diphosphonate (MDP) bone scanning, fluorine 18 (¹⁸F) fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT, and magnetic resonance (MR) imaging. Because of the diversity of imaging appearances and clinical behavior of this spectrum of disease, diagnosis can be challenging, and profound understanding of the underlying pathophysiologic changes and current treatment modalities can be daunting. The appearance of normal bone marrow at MR imaging and FDG PET/CT is also varied due to dynamic compositional changes with normal aging and in response to hematologic demand or treatment, which can lead to false-positive interpretation of imaging studies. In this article, the authors review the normal maturation and imaging appearance of bone marrow. Focusing on lymphoma, leukemia, and multiple myeloma, they present the spectrum of imaging findings of hematologic malignancy affecting the musculoskeletal system and the current imaging tools available to the radiologist. They discuss the imaging findings of posttreatment bone marrow and review commonly used staging systems and consensus recommendations for appropriate imaging for staging, management, and assessment of clinical remission. ^©RSNA, 2017.

EULAR-PReS points to consider for the use of imaging in the diagnosis and management of juvenile idiopathic arthritis in clinical practice

To develop evidence based points to consider the use of imaging in the diagnosis and management of juvenile idiopathic arthritis (JIA) in clinical practice. The task force comprised a group of paediatric rheumatologists, rheumatologists experienced in imaging, radiologists, methodologists and patients from nine countries. Eleven questions on imaging in JIA were generated using a process of discussion and consensus. Research evidence was searched systematically for each question using MEDLINE, EMBASE and Cochrane CENTRAL. Imaging modalities included were conventional radiography, ultrasound, MRI, CT, scintigraphy and positron emission tomography. The experts used the evidence obtained from the relevant studies to develop a set of points to consider. The level of agreement with each point to consider was assessed using a numerical rating scale. A total of 13 277 references were identified from the search process, from which 204 studies were included in the systematic review. Nine points to consider were produced, taking into account the heterogeneity of JIA, the lack of normative data and consequent difficulty identifying pathology. These encompassed the role of imaging in making a diagnosis of JIA, detecting and monitoring inflammation and damage, predicting outcome and response to treatment, use of guided therapies, progression and remission. Level of agreement for each proposition varied according to the research evidence and expert opinion. Nine points to consider and a related research agenda for the role of imaging in the management of JIA were developed using published evidence and expert opinion.

Arthritis as presenting manifestation of acute lymphoblastic leukaemia in children

BACKGROUND

At disease onset, children with acute lymphoblastic leukaemia (ALL) may present with arthralgia or even signs of arthritis. This might cause misdiagnosis and thereby lead to prolonged diagnostic delay. The present study aimed to identify children with ALL with joint involvement and to compare their characteristics and outcome with children with ALL without joint involvement.

METHODS

Case records of 286 children diagnosed with ALL between 1992 and 2013 were reviewed and analysed in this retrospective, descriptive study.

RESULTS

Fifty-three (18.5%) children with ALL presented with localised joint pain, and half of them had objective signs of arthritis. The mean number of joints involved was 2.5, most frequently presenting as asymmetric oligoarthritis. The suspected misdiagnosis were reactive arthritis (19/53), osteomyelitis (9/53) and juvenile idiopathic arthritis (8/53). Children with joint involvement had less objective signs of haematological disease. Cytopenia was absent in 24% in children with joint involvement (vs 8% without, p=0.001), 50% had only one cell line affected (vs 21%, p=0.0005) and 44% had no organomegaly (vs 29%, p=0.05). Median diagnostic delay was 4 vs 2 weeks. The 5-year event-free and overall survival was superior for children with joint involvement: 94% vs 87% (p=0.049), and 96% vs 83% (p=0.044).

CONCLUSIONS

ALL with joint involvement is a frequent finding (18.5%). The clinical signs of leukaemia are less prominent, but non-articular pain should alert the clinician of a possible diagnosis of leukaemia. The overall and event-free survivals were superior compared with the children without joint involvement.

Pediatric Rheumatology for the Primary Care Clinicians-Recognizing Patterns of Disease

This review presents a diagnostic approach to musculoskeletal and rheumatic diseases in children for primary care clinicians. The focus is on juvenile idiopathic arthritis (JIA) as the major arthritis disease in children. It is necessary to know the personalities of these JIA categories. It is also crucial to be able to recognize the common infectious, orthopedic and mechanical, malignant, genetic, other rheumatic diseases, and other miscellaneous syndromes that can mimic JIA. To do so requires recognition of clinical patterns using a thorough musculoskeletal and rheumatic history and repeated complete physical exams with emphasis on the musculoskeletal exam. It also requires targeted and limited laboratory testing with careful follow-up over time.

Survival rates of children with acute lymphoblastic leukemia presenting to a pediatric rheumatologist in the United States

BACKGROUND

Approximately 30% of pediatric acute lymphoblastic leukemia patients present with musculoskeletal symptoms and are often referred first to a pediatric rheumatologist. We examined the survival and causes of death of these patients presenting to a pediatric rheumatologist and compared the rates with that reported in the hematology-oncology literature.

PROCEDURE

We used the Pediatric Rheumatology Disease Registry, including 49,023 patients from 62 centers, newly diagnosed between 1992 and 2001. Identifiers were matched with the Social Security Death Index censored for March 2005. Deaths were confirmed by death certificates, referring physicians, and medical records. Causes of death were derived by chart review or from the death certificate.

RESULTS

There were 7 deaths of 89 patients (7.9%, 95% confidence interval: 3.9%-15.4%) with acute lymphoblastic leukemia with a 5-year survival rate of 95.5% (88.3 to 98.3) and 10-year survival rate of 89.8% (79.0% to 95.2%). The causes of death were sepsis (bacterial and/or fungal) in 4 (57%) patients, the disease in 2 (29%) and post bone-marrow transplantation in 1 (14%).

CONCLUSION

The overall survival of patients with acute lymphoblastic leukemia seen first by pediatric rheumatologists is higher than the range reported in the pediatric oncology literature for the same period of diagnosis.

Discrimination of acute lymphoblastic leukemia from systemic-onset juvenile idiopathic arthritis at disease onset

OBJECTIVE

To assess clinical and laboratory features that differentiate acute lymphoblastic leukemia from systemic juvenile idiopathic arthritis at disease onset.

METHODS

Fifty-seven leukemia patients with musculoskeletal involvement, without blasts on peripheral blood and without glucocorticoid therapy at disease onset and 102 systemic juvenile idiopathic arthritis patients (International League of Associations for Rheumatology criteria) were retrospectively evaluated. The following features were examined: fever, rheumatoid rash, arthritis, limb pain, hepatomegaly, splenomegaly, pericarditis, myocarditis, pleuritis, weight loss, bleeding, anemia, leukopenia, neutropenia, thrombocytopenia, erythrocyte sedimentation rate, and lactic dehydrogenase levels.

RESULTS

The median age at disease onset was significantly higher in leukemia patients than in those with systemic-onset juvenile idiopathic arthritis (5.8 vs. 3.8 years). In addition, the frequencies of limb pain, hepatomegaly, weight loss and hemorrhagic manifestations were significantly higher in leukemia patients than in systemic-onset juvenile idiopathic arthritis patients (70% vs. 1%, 54% vs. 32%, 30% vs. 8%, and 9% vs. 0%, respectively). Likewise, the frequencies of anemia, leukopenia, neutropenia, thrombocytopenia and high lactic dehydrogenase levels were statistically higher in leukemia patients than in patients with systemic-onset juvenile idiopathic arthritis (88% vs. 57%, 39% vs. 1%, 60% vs. 1%, 77% vs. 1%, and 56% vs. 14%, respectively). Remarkably, multivariate analysis revealed that limb pain (OR = 553; 95% CI = 46.48-6580.42) and thrombocytopenia (OR = 754.13; 95% CI = 64.57-8806.72) were significant independent variables that differentiated leukemia from systemic-onset juvenile idiopathic arthritis. The R2 of the Nagelkerke test was 0.91, and the Kaplan-Meier survival curves were similar for acute lymphoblastic leukemia patients with and without limb pain.

CONCLUSION

Our study emphasizes the importance of investigating leukemia in patients presenting with musculoskeletal manifestations and, in particular, limb pain associated with thrombocytopenia.

Summary of worldwide pediatric malignancies reported after exposure to etanercept

BACKGROUND

Concerns have been raised about a potential link between the use of TNF inhibitors and development of malignancy in the pediatric population. We examined the worldwide experience of etanercept use in pediatric patients and the occurrence of malignancies as reported from clinical trials, registry studies, post-marketing surveillance, and published scientific literature.

METHODS

All reports of "malignancy" in pediatric patients (including subjects who received etanercept before age 18 and developed a malignancy before age 22) were collected from the etanercept clinical trials database and global safety database using the Medical Dictionary for Regulatory Activities (MedDRA; v12.0) standardized MedDRA query "Malignancies" from 1998 to August 2009. Cases were collected irrespective of treatment indication. All cases were included regardless of exposure to other TNF blockers or other biologics and whether the other exposure was before or after etanercept.

RESULTS

A total of 18 potential malignancies were identified: 4 leukemias, 7 lymphomas, and 7 solid tumors. Three of the 18 malignancies remain unconfirmed. No malignancies were reported from clinical trials or the open-label extension studies in any indication in children.

CONCLUSION

The data suggest that there does not appear to be an increased risk of malignancy overall with the use of etanercept. Among etanercept-exposed patients aged 4 to 17 years, the estimated worldwide and US reporting rates for lymphoma were approximately 0.01 per 100 patient-years (1 in 10,000 pt-yrs). While the reported rate of lymphoma is higher in pediatric patients treated with etanercept than in normal children, the expected rate of lymphoma in biologic naïve JIA patients is currently unknown. The risk of TNF inhibitors in the development of malignancies in children and adolescents is difficult to assess because of the rarity of malignant events, the absence of knowledge of underlying frequency of leukemia and lymphoma in JIA, and the confounding use of concomitant immunosuppressive medications.