Carpal erosions in children with juvenile idiopathic arthritis: repeatability of a newly devised MR-scoring system.

BACKGROUND: Juvenile idiopathic arthritis (JIA) is characterized by synovial inflammation, with potential risk of developing progressive joint destruction. Personalized state-of-the-art treatment depends on valid markers for disease activity to monitor response; however, no such markers exist. OBJECTIVE: To evaluate the reliability of scoring of carpal bone erosions on MR in children with JIA using two semi-quantitative scoring systems. MATERIALS AND METHODS: A total of 1,236 carpal bones (91 MR wrist examinations) were scored twice by two independent pediatric musculoskeletal radiologists. Bony erosions were scored according to estimated bone volume loss using a 0-4 scale and a 0-10 scale. An aggregate erosion score comprising the sum total carpal bone volume loss was calculated for each examination. RESULTS: The 0-4 scoring system resulted in good intra-reader agreement and moderate to good inter-observer agreement in the assessment of individual bones. Fair and moderate agreement were achieved for inter-reader and intra-reader agreement, respectively, using the 0-10 scale. Intra- and particularly inter-reader aggregate score variability were much less favorable, with wide limits of agreement. CONCLUSION: Further analysis of erosive disease patterns compared with normal subjects is required, and to facilitate the development of an alternative means of quantifying disease.

MRI of the wrist in juvenile idiopathic arthritis: erosions or normal variants? A prospective case-control study.

BACKGROUND: Bony depressions at the wrist resembling erosions are frequently seen on MRI in healthy children. The accuracy of MRI in detecting early bony destruction is therefore questionable. We compared findings on MRI of the wrist in healthy children and those with juvenile idiopathic arthritis (JIA) to investigate markers for true disease. MATERIALS AND METHODS: We compared the number and localisation of bony depressions at the wrist in 85 healthy children and 68 children with JIA, ages 5-15 years. The size of the wrist was assessed from a radiograph of the wrist performed on the same day as the MRI. RESULTS: No significant difference in the number of bony depressions in the carpal bones was seen between healthy children and children with JIA at any age. Depressions are found in similar locations in the two groups, except for a few sites, where bony depressions were seen exclusively in the JIA group, particularly at the CMC joints. The wrist was significantly smaller in children with JIA (P < 0.001). CONCLUSIONS: Using adult scoring systems and standard MR sequences in the assessment of bone destruction in children may lead to overstaging or understaging of disease. At present, standard MRI sequences cannot easily be used for assessment of early signs of erosions in children.

MRI assessment of bone marrow in children with juvenile idiopathic arthritis: intra- and inter-observer variability.

BACKGROUND: Bone marrow oedema (BMO) is included in MRI-based scoring systems of disease activity in adults with rheumatoid arthritis. Similar systems in juvenile idiopathic arthritis (JIA) are lacking. OBJECTIVE: To assess the reproducibility in a multi-centre setting of an MRI BMO scoring system in children with JIA. MATERIALS AND METHODS: Seventy-six wrist MRIs were read twice, independently, by two experienced paediatric radiologists. BMO was defined as ill-defined lesions within the trabecular bone, returning high and low signal on T2- and T1-weighted images respectively, with or without contrast enhancement. BMO extension was scored for each of 14 bones at the wrist from 0 (none) to 3 (extensive). RESULTS: The intra-observer agreement was moderate to excellent, with weighted kappa ranging from 0.85 to 1.0 and 0.49 to 1.0 (readers 1 and 2 respectively), while the inter-observer agreement ranged from 0.41 to 0.79. The intra- and inter-observer intraclass correlation coefficients were excellent and satisfactory, respectively. CONCLUSION: The scoring system was reliable and may be used for grading bone marrow abnormality in JIA. The relatively large variability in aggregate scores, particularly between readers, underscores the need for thorough standardisation.

Feasibility and efficacy of chronic transfusion for stroke prevention in children with sickle cell disease.

OBJECTIVES: In children with sickle cell disease (SCD), chronic transfusion to maintain haemoglobin S (HbS) below 30% markedly decreases both the risk of a first stroke when transcranial Doppler (TCD) ultrasonography shows abnormal cerebral blood flow velocities and the risk of recurrent stroke. Maintaining HbS below 30% may be difficult, especially in countries where blood donors and recipients belong to different ethnic groups and where the availability of closely matched blood products is limited. We assessed the feasibility and efficacy of chronic transfusion with an HbS target of 30% in children with SCD living in the Paris area. METHODS: We retrospectively studied 29 children aged 6.8 +/- 3.0 yr (3-15 yr) at inclusion who received chronic transfusion either because of abnormal TCD findings (primary prevention group, PPG, n = 17) or because of a previous cerebrovascular event (secondary prevention group, SPG, n = 12 including nine with a history of stroke and three of transient ischaemic attacks). RESULTS: Mean follow-up was 3.5 +/- 3.0 yr (0.5-12 yr). No cases of stroke occurred in the PPG. In the SPG, one patient with a history of stroke and severe cerebrovascular disease had a recurrence after 11 yr of chronic transfusion, when the HbS level was 20%. The stroke recurrence rate (SPG group) was 1.6/100 patient-years. Mean HbS levels before and after transfusion were 30 +/- 10% and 20.6 +/- 7%, respectively. Two patients acquired red-cell alloantibodies. Of the 29 patients, 22 required iron chelation. CONCLUSIONS: Regular transfusion maintaining HbS below 30% is feasible and safe in children with SCD in France and protects from overt stroke.

Thrombotic microangiopathy and Purtscher-like retinopathy as a rare presentation of juvenile dermatomyositis.

Juvenile dermatomyositis is a rare systemic vasculopathy that may sometimes present with acute complications. We report here the case of a 7-year-old boy with severe dermatomyositis associated with thrombocytopenia and blurry vision. The presence of schistocytosis and the secondary occurrence of hemolytic anemia were consistent with a diagnosis of thrombotic thrombocytopenic purpura (TTP). Further investigations demonstrated the association of TTP with muscular microangiopathy and Purtscher-like retinopathy. Retinal and hematologic involvements dramatically improved after the initiation of plasma exchange in emergency. This report emphasizes that early recognition of TTP and prompt plasmapheresis are important in a child with severe juvenile dermatomyositis associated with thrombocytopenia.