Kawasaki disease (KD) is an acute self-limited systemic vasculitis of unknown etiology affecting mainly children less than 5 years of age. Risk factors for cardiac involvement and resistance to treatment are insufficiently studied in non-Japanese children. This study aimed to investigate the epidemiology, clinical features and risk factors for resistance to treatment and coronary artery lesions (CAL) in KD in Spain. Retrospective study (May 2011-June 2016) of all patients less than 16 years of age diagnosed with KD included in KAWA-RACE network (84 Spanish hospitals). A total of 625 cases were analyzed, 63% were males, 79% under 5 year-olds and 16.8% younger than 12 months. On echocardiographic examination CAL were the most frequent findings (23%) being ectasia the most common (12%). Coronary aneurysms were diagnosed in 9.6%, reaching 20% in infants under 12 months (p<0.001). A total of 97% of the patients received intravenous immunoglobulin (IVIG) with a median number of days from fever onset to IVIG administration of 7.2. A second dose was given to 15.7% and steroids to 14.5% patients. Only 1.4% patients received infliximab. No deaths were reported. A multivariate analysis identified anemia, hypoalbuminemia, hyponatremia, higher creatinine and procalcitonin as independent risk factors for treatment failure and length under 103 cm, hemoglobin < 10.2 mg/dL, platelets > 900,000 cells/mm³, maximum temperature < 39.5°C, total duration of fever > 10 days and fever before treatment ≥ 8 days as independent risk factors for developing coronary aneurysms. In our population, children under 12 months develop coronary aneurysms more frequently and children with KD with anemia and leukocytosis have high risk of cardiac involvement. Adding steroids early should be considered in those patients, especially if the treatment is not started before 8 days of fever. A score applicable to non-Japanese children able to predict the risk of aneurysm development and IVIG resistance is necessary.

Kawasaki disease (KD) is an acute self-limited systemic vasculitis of unknown etiology. Intravenous immunoglobulin (IVIG) is an effective treatment and decreases the risk of cardiac complications to less than 5%. In spite of its effectiveness, some children do not respond to this therapy and still develop coronary aneurysms (CAA). The optimal treatment for IVIG non-responsive patients remains controversial although corticoids have been suggested to be an effective treatment in some patients. For those patients still resistant to IVIG and corticoids, interleukin-1 receptor antagonists (IL-1RA) such anakinra could be an alternative. We present a 3 year-old Caucasian patient with KD without cardiac complications but with important resistance to treatment. After becoming resistant to IVIG and corticoids, anakinra proved to be an effective treatment. To our knowledge, this is the first report of the utility of IL-1RA in refractory KD without coronary impairment. The patient fulfilled the classical criteria for KD and, after becoming resistant to first and second line treatments, anakinra proved to be an effective treatment. Further studies are required to determine if this is an effective treatment option for other cases of resistant Kawasaki disease.

Adult patients receiving anti-TNFα drugs are at increased risk of tuberculosis (TB), but studies in pediatric populations are limited, and the best strategy for latent tuberculosis infection (LTBI) screening in this population remains controversial. We describe the prevalence of LTBI prior to anti-TNFα therapy and the long-term follow-up after biological treatment initiation in a cohort of children and adolescents. Cohort observational study in children and adolescents receiving anti-TNFα agents in a tertiary-care pediatric hospital. LTBI was ruled out prior to the implementation of anti-TNFα drugs by tuberculin skin test (TST), and, from March 2012 on, QuantiFERON Gold-In Tube® test (QTF-G). During anti-TNFα treatment, patients were evaluated every 6 months for TB with history and physical examination. TST/QTF-G were not repeated unless signs or symptoms consistent with TB arose or there was proven TB contact. The final cohort consisted of 221 patients (56.1 % female; 261 treatments), of whom 51.7 %/30.0 %/17.3 % were treated with etanercept/adalimumab/infliximab, respectively, for a variety of rheumatic diseases (75.6 %), inflammatory bowel disease (20.8 %), and inflammatory eye diseases (3.6 %). The median (IQR) age at diagnosis of the primary condition was 6.8 years (2.7–11.0) and the duration of the disease before implementing the anti-TNFα agent was 1.8 years (0.6–4.2). LTBI was diagnosed in 3 adolescent girls (prevalence rate: 1.4 %; 95 % CI: 0.4–4.2) affected with juvenile idiopathic arthritis: TST tested positive in only 1, while QTF-G was positive in all cases (including 2 patients already on etanercept). They all received antiTB chemoprophylaxis and were later (re)treated with etanercept for 24–29 months, without incidences. No incident cases of TB disease were observed during the follow-up period under anti-TNFα treatment of 641 patients-year, with a median (IQR) time per patient of 2.3 years (1.4–4.3). In our study, the prevalence of LTBI (1.4 %) was similar to that reported in population screening studies in Spain; no incident cases of TB disease were observed. In low-burden TB settings, initial screening for TB in children prior to anti-TNFα treatment should include both TST and an IGRA test, but systematic repetition of LTBI immunodiagnostic tests seems unnecessary in the absence of symptoms or known TB contact.