P0575 - Assessing the Need for Hematology Evaluation of Cytopenia in Children with Respiratory Viral Illnesses

Background: Acquired cytopenias, especially neutropenia, are common in pediatric practice in the setting of viral and bacterial illnesses. Hematologists are sometimes consulted for guidance to perform further diagnostic testing. It is unknown whether or not these consultations change clinical outcomes for patients.

Methods: Children from 3 months to 10 years old admitted with the ICD-10 diagnosis of leukopenia, neutropenia, lymphopenia, anemia, thrombocytopenia, or pancytopenia between January 2015 and December 2019 were identified. Hospital records were reviewed to confirm the diagnosis of a respiratory viral infection. The following were recorded: patient demographics, risk factors, clinical characteristics, laboratory results, and hospitalization outcomes. Excluded patients were those who were immunocompromised, on medications that cause cytopenia, had cystic fibrosis or a tracheostomy, prior cytopenia, Kawasaki Disease, anemia due to nutritional deficiencies, or other concurrent bacterial illnesses. Chi-squared testing was used to detect categorical variables that were significantly associated with hematology evaluation. The Mann-Whitney test was used to detect outcomes of continuous variables that were significant between those evaluated by a hematologist and those who were not. Statistical significance was defined as p<0.05.

Results: We included 262 patients in this study. The most commonly identified cytopenia was neutropenia. Among 170 neutropenic patients, concurrent anemia occurred in 17 (10%) patients and concurrent thrombocytopenia occurred in 64 (38%) patients. A respiratory viral agent was identified in 168 (64%) of patients with the most common being respiratory syncytial virus. Influenza B was the most common virus to cause neutropenia. Overall, 58 (22%) patients were evaluated by a hematologist. On chi-squared analysis, patients with no identification of a viral pathogen, odds ratio (OR) = 3.40, 95% confidence interval (CI) [1.86-6.14] and more than one cell line affected, OR = 2.34, CI [1.29-4.31] were significantly associated with a hematologist evaluation. Improvement of cytopenia prior to discharge was not significant. Patients who were evaluated by a hematologist had significantly longer length of stay, longer duration of symptoms prior to admission, lower white cell count, lower hemoglobin, lower platelet count, and lower absolute neutrophil count during admission. A diagnostic bone marrow aspiration was performed in 10 (4%) patients. All biopsies were normal.

Conclusion: Respiratory viral illnesses may affect one or more hematological cell lines, prompting evaluation by a specialist particularly if there is no identifiable pathogen or if there are multiple cell lines affected. Length of stay was longer for these patients, but most patients were still discharged without improvement in cytopenia. This study suggests that children with viral illnesses and new onset cytopenia may not need extensive inpatient work-up, but that follow-up as an outpatient for count recovery may be sufficient.