A cross-sectional retrospective study to analyze the underlying causes and clinical characteristics of children with reactive thrombocytosis at a Korean tertiary medical center

Abstract

BackgroundReactive thrombocytosis (RT) is a common condition among children, although no studies have examined the etiology or clinical characteristics of RT among Korean children.MethodsThis retrospective study evaluated children with RT at a single Korean tertiary center during a 10-year period.ResultsRT accounted for 13.5% of children who were admitted to the pediatric ward (4,113/30,355): mild RT, 82.7%; moderate RT, 14.1%; severe RT, 1.1%; and extreme RT, 2.1%. There was a negative correlation between platelet count and Hb level (P=0.008). There were positive correlations between platelet count and WBC (P=0.001), erythrocyte sedimentation rate (ESR) (P=0.007), and admission duration (P=0.006). The most common cause of RT was infection and the second most common was Kawasaki disease (KD). The highest proportion of lower respiratory tract infection was observed in extreme RT (P<0.001). The proportion of KD was highest in extreme RT (P<0.001) and in children aged 1–7.9 years (P<0.001). The proportion of refractory KD was highest in extreme RT (P=0.005). In cases of KD, there was a positive correlation between platelet count and fever duration (P=0.006). Non-KD autoimmune inflammation was only observed in mild/moderate RT, and its proportion was highest in children aged 8–18 years (P<0.001).ConclusionIn children, more severe RT was associated with lower Hb, increased WBC, ESR, and prolonged admission. With respiratory infection or KD, extreme RT was associated with more severe disease course.

Update on current views and advances on RSV infection (Review)

“…conversely, other authors have found that platelet counts do not correlate with disease severity and clinical outcome (68,69). Routine prophylactic anti-platelet treatment or further investigations are not necessary in children with RSV-positive bronchiolitis and thrombocytosis (61,68,70).…”

“…The most frequent causes of secondary thrombocytosis in childhood are acute respiratory tract infections (57)(58)(59)(60)(61). To date, several authors have reported significantly higher mean platelet counts in patients with RSV than in patients with other acute respiratory tract infections (61)(62)(63)(64). Thrombocytosis is more likely to occur in younger patients, who have clinical manifestations of wheezing and dyspnoea (62,64).…”

“…Excessive thrombocytosis has also been detected at an early stage in cases of RSV-positive bronchiolitis (65). It has been proposed that thrombocytotic patients have a more severe clinical course and longer duration of hospitalization and that the platelet count may be a useful clinical marker associated with ALRTI severity (61,64,66,67). conversely, other authors have found that platelet counts do not correlate with disease severity and clinical outcome (68,69).…”

Iron and platelets: A subtle, under‐recognized relationship

“…75 Thrombopoietin may be involved in this thrombopoiesis activation mechanism through its stimulation by IL-6. 76 Clinically, inflammation-related thrombocytosis is observed in infectious diseases 77 but also in non-infectious ones such as inflammatory bowel disease, 78,79 where a correlation has been found between plasma hepcidin levels and platelet counts, 80 auto-immune disorders (systemic lupus erythematosus, 81 juvenile arthritis 82 ), various malignancies including solid tumors, 83 or chronic myeloproliferative neoplasms, 84 in which thrombocytosis can also, of course, be of primary origin. As for the thrombotic risk, it may result from the conjunction of reactive thrombocytosis and the natural history of the causal disease.…”

Essential Thrombocythemia in Children and Adolescents

“…Moreover, many interleukins (IL) involved in the inflammation processes, mostly IL-6 and IL-11, can stimulate the platelet production in the liver [ 27 , 28 ]. These processes are highly active during childhood: ST is reported in 6–15% of hospitalized children, and up to 1% of children in intensive care units show platelet counts exceeding 1000 × 10 9 /L [ 5 , 29 , 30 , 31 , 32 , 33 , 34 , 35 ].…”