Development and Initial Validation of the ONCOREUM Score to Differentiate Childhood Cancer with Arthropathy from Juvenile Idiopathic Arthritis.

OBJECTIVE: To develop and validate a weighted score, the ONCOREUM score, that aids physicians in differentiation of cancer with arthropathy from juvenile idiopathic arthritis (JIA). STUDY DESIGN: Data were extracted from the ONCOREUM Study, a multicenter, cross-sectional investigation aimed at comparing children with cancer and arthropathy to children with JIA. Three statistical approaches were applied to develop the ONCOREUM score and assess the role of each variable in the diagnosis of cancer with arthropathy, including 2 approaches based on multivariable stepwise selection (models 1 and 2) and 1 approach on a Bayesian model averaging method (model 3). The ß coefficients estimated in the models were used to assign score points. Considering that not missing a child with cancer is a mandatory clinical objective, discriminating performance was assessed by fixing sensitivity at 100%. Score performance was evaluated in both developmental and validation samples (representing 80% and 20% of the study population, respectively). RESULTS: Patients with cancer and arthropathy (49 with solid tumors and 46 with hematologic malignancies without peripheral blasts) and 677 patients with JIA were included. The highest area under the receiver operating characteristic (ROC) curve (AUC) in the validation data set was yielded by model 1, which was selected to constitute the ONCOREUM score. The score ranged from -18 to 21.8, and the optimal cutoff obtained through ROC analysis was -6. The sensitivity, specificity, and AUC of the cutoff in the validation sample were 100%, 70%, and 0.85, respectively. CONCLUSIONS: The ONCOREUM score is a powerful and easily applicable tool that may facilitate early differentiation of malignancies with articular complaints from JIA.

Discordance between Clinical and Ultrasound Examinations in Juvenile Idiopathic Arthritis: An Experimental Approach.

Clinical examination (CE) and musculoskeletal ultrasound (MSUS) of ten joints (knee, ankle, wrist, elbow, II-MCP) and their extra-articular (EA) compartments (tendons and bursae) were performed on 35 consecutive patients with active juvenile idiopathic arthritis (JIA) (active group) to test how the extension of MSUS examinations to EA changes the concordance between MSUS and CE. The overall concordance between CE and MSUS, measured with Cohen's Kappa (k), was moderate (k = 0.43); the addition of EA MSUS increased the concordance in all joints, with the exclusion of II-MCP (k = 0.49). In the ankle and wrist, the k increase was relevant (k from 0.13 to 0.27 and 0.11 to 0.41). In the active group patients, we observed 44 subclinical synovitis; the number of subclinical synovitis per patient was correlated with JADAS-27 (p = 0.03) and was higher in a control group composed of 15 patients with persistent disease remission (1.3 vs. 0.4 p = 0.03). Our results show that EA compartments should always be evaluated during MSUS. Furthermore, we demonstrate a moderate concordance between CE and MSUS in JIA; the finding of subclinical synovitis is common in patients with active diseases and is related to disease activity.

Musculoskeletal manifestations of childhood cancer and differential diagnosis with juvenile idiopathic arthritis (ONCOREUM): a multicentre, cross-sectional study.

BACKGROUND: Presenting symptoms of childhood cancers might mimic those of rheumatic diseases. However, the evidence available to guide differential diagnosis remains scarce. Preventing wrong or delayed diagnosis is therefore important to avoid incorrect administration of glucocorticoid or immunosuppressive therapy and worsening of prognosis. As such, we aimed to assess the prevalence and characteristics of presenting musculoskeletal manifestations in patients at cancer onset and to identify the factors that differentiate childhood malignancies with arthropathy from juvenile idiopathic arthritis. METHODS: We did a multicentre, cross-sectional study at 25 paediatric haemato-oncology centres and 22 paediatric rheumatology centres in Italy. We prospectively recruited patients who were younger than 16 years that were newly diagnosed with cancer or juvenile idiopathic arthritis. We excluded patients with glucocorticoid pre-treatment (>1 mg/kg per day of oral prednisone or equivalent for ≥2 consecutive weeks). We collected data for patients with a new diagnosis of cancer or juvenile idiopathic arthritis using an electronic case report form on a web-based platform powered by the Cineca Interuniversity Consortium. The primary outcome was to describe the frequency and characteristics of musculoskeletal manifestations at cancer onset; and the secondary outcome was to identify factors that could discriminate malignancies presenting with arthropathy, with or without other musculoskeletal symptoms, from juvenile idiopathic arthritis using multivariable logistic regression analysis. FINDINGS: Between May 1, 2015, and May 31, 2018, 1957 patients were eligible, of which 1277 (65%) had cancer and 680 (35%) had juvenile idiopathic arthritis. Musculoskeletal symptoms occurred in 324 (25% [95% CI 23·0-27·8]) of 1277 patients with cancer, of whom 207 had arthropathy. Patients with malignant bone tumours had the highest frequency of musculoskeletal symptoms (53 [80%] of 66), followed by patients with Langerhans histiocytosis (16 [47%] of 34), leukaemia (189 [32%] of 582), soft-tissue sarcomas (16 [24%] of 68), and neuroblastoma (21 [19%] of 109). In the 324 patients with cancer and musculoskeletal symptoms, the most common complaints were joint pain (199 [61%]), followed by limb bone pain (112 [35%]). Joint involvement had a prevalent monoarticular pattern (100 [48%] of 207) and oligoarticular pattern (86 [42%] had 2-4 joints involved and 20 [10%] had >4 joints involved), with the most frequently involved joints being the hip (88 [43%] of 207) and knee (81 [39%]). On multivariable analysis, limb bone pain was the independent variable most strongly associated with cancer (odds ratio [OR] 87·80 [95% CI 18·89-408·12]), followed by weight loss (59·88 [6·34-565·53]), thrombocytopenia (12·67 [2·40-66·92]), monoarticular involvement (11·30 [4·09-31·19]), hip involvement (3·30 [1·13-9·61]), and male sex (2·40 [1·03-5·58]). Factors independently associated with juvenile idiopathic arthritis were morning stiffness (OR 0·04 [95% CI 0·01-0·20]), joint swelling (0·03 [0·01-0·09]), and involvement of the small hand joints (0·02 [0-1·05]). INTERPRETATION: Our study provides detailed information about presenting musculoskeletal manifestations of childhood cancers and highlights the clinical and laboratory features that are most helpful in the differential diagnosis with juvenile idiopathic arthritis. FUNDING: Associazione Lorenzo Risolo.

Cryopyrin-associated Periodic Syndromes in Italian Patients: Evaluation of the Rate of Somatic NLRP3 Mosaicism and Phenotypic Characterization.

OBJECTIVE: To evaluate the rate of somatic NLRP3 mosaicism in an Italian cohort of mutation-negative patients with cryopyrin-associated periodic syndrome (CAPS). METHODS: The study enrolled 14 patients with a clinical phenotype consistent with CAPS in whom Sanger sequencing of the NLRP3 gene yielded negative results. Patients' DNA were subjected to amplicon-based NLRP3 deep sequencing. RESULTS: Low-level somatic NLRP3 mosaicism has been detected in 4 patients, 3 affected with chronic infantile neurological cutaneous and articular syndrome and 1 with Muckle-Wells syndrome. Identified nucleotide substitutions encode for 4 different amino acid exchanges, with 2 of them being novel (p.Y563C and p.G564S). In vitro functional studies confirmed the deleterious behavior of the 4 somatic NLRP3 mutations. Among the different neurological manifestations detected, 1 patient displayed mild loss of white matter volume on brain magnetic resonance imaging. CONCLUSION: The allele frequency of somatic NLRP3 mutations occurs generally under 15%, considered the threshold of detectability using the Sanger method of DNA sequencing. Consequently, routine genetic diagnostic of CAPS should be currently performed by next-generation techniques ensuring high coverage to identify also low-level mosaicism, whose actual frequency is yet unknown and probably underestimated.

A neonatal case of 3-hydroxy-3-methylglutaric-coenzyme A lyase deficiency.

3-hydroxy-3-methylglutaric aciduria (OMIM 246450) is a rare autosomal recessive inborn of metabolism due to the deficiency of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) lyase, an enzyme involved both in the ketogenic pathway and leucine catabolism. Acute decompensations present with lethargy, cianosis, hypotonia, vomiting and metabolic acidosis with hypoketotic hypoglycemia. We report the case of a 3 days male with sudden hypoglycemic crisis initially misdiagnosed as a sepsis. HMG-CoA lyase deficiency was achieved through acyl-carnitines profile (showing a typical increasing of 3-hydroxy-isovaleryl and 3-methylgluraryl carnitines) and urinary organic acids analysis (disclosing elevation of 3-hydroxy-3-methylglutaric, 3-methyl-glutaconic, 3-methylglutaric and 3-hydroxyisovaleric acids). This case underlines the need of suspecting such inborn metabolic disorder in cases with hypoglycemia and metabolic acidosis. Acyl-carnitine and urinary organic acids profiles are essential to achieve a prompt diagnosis of treatable metabolic disorders in order to prevent their acute crisis with serious or even fatal consequences.