Interference from heterophilic antibodies in D-dimer assessment. A case report.

We describe the case of a 3-year-old girl, admitted to the pediatric ward for three repeated episodes of severe migraine associated with vertigo, with onset 1 week after complete remission from an episode of chicken pox (i.e., varicella-zoster virus infection). All radiological and laboratory examinations were normal, except for a markedly elevated value of D-dimer (i.e. 8998 ng/ml; local reference range: < 243 ng/ml), measured with a commercial latex-enhanced immunoturbidimetric assay. After physical and Doppler ultrasound examination, possible presence of thrombosis was ruled out, and the patient was discharged. In the following year, however, her plasma D-dimer values always remained frankly elevated, so that an analytical interference was suspected. A plasma sample was treated with a specific heterophilic antibodies blocking reagent and then assayed along with the untreated sample, with these showing a marked discrepancy of D-dimer values, that is 232 versus 2877 ng/ml. These results, highly indicative for the presence of heterophilic antibodies, are discussed in the light of the serious challenges that this type of analytical interference may pose on quality and reliability of D-dimer testing.

Oral ondansetron versus domperidone for symptomatic treatment of vomiting during acute gastroenteritis in children: multicentre randomized controlled trial.

BACKGROUND: Vomiting in children with acute gastroenteritis (AG) is not only a direct cause of fluid loss but it is also a major factor of failure of oral rehydration therapy (ORT). Physicians who provide care to paediatric patients in the emergency department (ED) usually prescribe intravenous fluid therapy (IVT) for mild or moderate dehydration when vomiting is the major symptom. Thus, effective symptomatic treatment of vomiting would lead to an important reduction in the use of IVT and, consequently, of the duration of hospital stay and of frequency of hospital admission. Available evidence on symptomatic treatment of vomiting shows the efficacy of the most recently registered molecule (ondansetron) but a proper evaluation of antiemetics drugs largely used in clinical practice, such as domperidone, is lacking. OBJECTIVES: To compare the efficacy of ondansetron and domperidone for the symptomatic treatment of vomiting in children with AG who have failed ORT. METHODS/DESIGN: Multicentre, double-blind randomized controlled trial conducted in paediatric EDs. Children aged from 1 to 6 years who vomiting, with a presumptive clinical diagnosis of AG, and without severe dehydration will be included. After the failure of a initial ORS administration in ED, eligible children will be randomized to receive: 1) ondansetron syrup (0,15 mg/Kg of body weight); 2) domperidone syrup (0,5 mg/Kg of body weight); 3) placebo. The main study outcome will be the percentage of patients needing nasogastric or IVT after symptomatic oral treatment failure, defined as vomiting or fluid refusal after a second attempt of ORT. Data relative to study outcomes will be collected at 30 minute intervals for a minimum of 6 hours. A telephone follow up call will be made 48 hours after discharge. A total number of 540 children (i.e. 180 patients in each arm) will be enrolled. DISCUSSION: The trial results would provide evidence on the efficacy of domperidone, which is largely used in clinical practice despite the lack of proper evaluation and a controversial safety profile, as compared to ondansetron, which is not yet authorized in Italy despite evidence supporting its efficacy in treating vomiting. The trial results would contribute to a reduction in the use of IVT and, consequently, in hospital admissions in children with AG. The design of this RCT, which closely reflect current clinical practice in EDs, will allow immediate transferability of results. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01257672.