At birth, Down syndrome (DS) is the most common chromosome abnormality. A high incidence of acquired diseases, in particular, infections and autoimmune disorders, has been described in this condition [Ugazio et al., 1990]. Congenital heart defects play a major role in affecting prognosis; an accurate echocardiographic evaluation, in addition to the usual clinical and laboratory tests, is usually recommended. In this study, we performed a prospective analysis on the data obtained during echocardiographic examinations in DS patients without heart malformations. Unexpectedly, a significantly high prevalence of pericardial effusion (PE) was found in our patients compared with control children. We then evaluated prospectively the PE over the next 2 years. PE is frequently found in children with infectious diseases, usually viral infections, hypothyroidism [Gonzalez et al., 1998], and celiac disease [Riccabona and Rossipal, 2000]. Some reports have suggested that PE in DS may correlate with transient abnormal myelopoiesis [Hirashima et al., 2000], acquired hypothyroidism [Werder et al., 1993], and celiac disease [Riccabona and Rossipal, 2000]. Recent studies suggest that PE might be an echographic marker for prenatal diagnosis of DS [DeVore, 2000].
A total of 86 children (40 males, 46 females) with DS (age range: 1 month-19 years, median 36 months) from Calabria, Southern Italy, without congenital cardiac malformations, were studied for the presence of PE over 2 years with echocardiograms every 3 months. One hundred healthy children (50 males, 50 females; age range: 2 months-18 years, median 34 months), matched for age and demographic characteristics, were enrolled in the study during the same period and were evaluated with the same frequency. The echocardiographic evaluation was performed by M,B-mode and by color Doppler. We distinguish between mild, moderate, and severe PE, depending on the volume of pericardial fluid: mild, 3-4 mm; moderate, 5-10 mm; severe >10 mm. All individuals with PE underwent clinical examination with careful anamnesis in order to identify transient abnormal myelopoiesis and symptoms suggestive of infections, all had chest radiographs in order to identify pleural effusions. We performed blood tests in order to identify, eventually, a pathogenetic correlation of PE with thyroid dysfunction, celiac disease, and infections; in particular, blood cell count, sedimentation rate, C reactive