Identification of nucleated red blood cells in maternal circulation: a second step in screening for fetal aneuploidies and pregnancy complications.

BACKGROUND: Identification of fetal nucleated red blood cells (NRBCs) in maternal circulation can facilitate non-invasive prenatal diagnosis, but technical difficulties still exist. An increase in the number of circulating NRBCs, however, could indicate fetal aneuploidies or pregnancy complications. MATERIALS AND METHODS: The number of NRBCs was determined from 20 mL peripheral blood in 351 women in the second trimester of pregnancy after isolation by magnetic cell sorting (MACS) with anti-CD71 antibody and identification with May-Grunwald/Giemsa staining. RESULTS: An average of eight NRBCs (range 1-12) were identified among 282 women with chromosomally normal fetuses. In cases known to carry aneuploid fetuses the mean number was 35 (range 7-113), but when the fetus had trisomy 21 (n = 17) an average of 71 NRBCs were identified. Among 26 carriers of beta-thalassemia, 42 NRBCs (range 22-158) were isolated. In pregnancies with abnormal Doppler findings in both uterine arteries (n = 20), 15 NRBCs (range 2-75) were isolated. CONCLUSION: Determining the number of NRBCs in maternal circulation could represent an additional screening step for fetal aneuploidies, as long as the anemic status of the mother is taken into consideration. However, more cases with abnormal Doppler results must be investigated before this test is used for in the prediction of pregnancy complications.

Identification of autosomal supernumerary chromosome markers (SMCs) by fluorescent in situ hybridization (FISH).

Supernumerary marker chromosomes (SMCs) are rare chromosomal abnormalities resulting in partial trisomy of specific genomic regions with characteristic phenotypic effects. Twenty six cases with autosomal SMCs are reported. Four were identified prenatally and 22 postnatally in children, aged from 8 days to 15 years, who were referred for genetic evaluation because of various congenital anomalies and developmental delay. In 22 of the 26 cases, the SMCs were de novo, in two they were familial and in another two a 11;22 reciprocal translocation was revealed in the mothers. In only one patient was the SMC present in a mosaic form. Sequential fluorescent in situ hybridization studies (FISH) using Whole Chromosome Paint (WCP) probes were performed in order to determine the chromosomal origin of the SMCs. Sixteen of them originated from chromosome 15, five were shown to be an isochromosome 18p and one was derived from chromosome 22, but did not contain the DiGeorge/ VCFS critical region. In two instances, the SMCs were derivatives of chromosome 13 and in two the SMCs resulted from a 11;22 maternal translocation and contained material from both chromosomes 11 and 22. Molecular investigation of two of the patients with an SMC[15] revealed three copies of the SNRPN gene, but the diagnosis of PW/AS due to possible imprinting was excluded in both patients by a methylation-specific PCR. FISH and molecular studies have greatly facilitated the characterization of marker chromosomes. As more SMCs are classified, better genetic counseling and risk evaluation can be achieved.

Ondansetron and tropisetron in the control of nausea and vomiting in children receiving combined cancer chemotherapy.

Ondansetron (Zofron, Glaxo) and tropisetron (Navoban, Sandoz) are selective serotonin (5HT3) antagonists that have proven very effective in the prevention of vomiting and nausea in adults and children receiving cancer chemotherapy. This study compared the efficacy of the two agents in the prevention of vomiting and nausea in children receiving chemotherapy for solid tumors and blood malignancies. A total of 23 children were studied in 205 chemotherapeutic cycles (116 one-day regimens and 89 multiple-day regimens). In 102 chemotherapeutic cycles the children received ondansetron as an antiemetic agent in a dose of 5 mg/m2 30 min before chemotherapy was given and then 4 mg/m2 every 8 h i.v. (group A) and in 103 cycles they received tropisetron in one dose of 0.2 mg/kg 24 h-1 i.v. (max dose 5 mg) 30 min before cytotoxic drugs administration every day they received chemotherapy (group B). The response was defined as complete in the absence of nausea and vomiting per 24 h of chemotherapy, as partial given the presence of 1-4 events of vomiting and/or nausea less than 5 h per 24 h, and as failure if there were more than 4 events of vomiting and/or nausea for more than 5 h per 24 h of chemotherapy. The response of the two groups was studied independently and depending on the degree of emetogenicity of the chemotherapeutic agents, which were divided into mildly, moderately, and highly emetogenic. The comparison of the two groups not taking into consideration the emetogenicity of the chemotherapeutic agents showed that ondansetron was more effective in 1-day regimens (P = .023), whereas the two agents were equally effective in multiple-day regimens (P = .2). The statistical analysis depending on the emetogenicity of the chemotherapeutic agents showed increased efficacy of ondansetron in mild (P = .017) and moderately emetogenic chemotherapeutic agents, whereas there was no difference in the highly emetogenic drug group. Ondansetron is found to be more effective than tropisetron in controlling acute nausea and vomiting in children receiving mild and moderately emetogenic chemotherapeutic drugs, although there is no difference in the efficacy of both antiemetic agents when highly emetogenic drugs are administered.

Congenital systemic Langerhans cell histiocytosis (report of two cases).

Two cases of congenital systemic Langerhans cell histiocytosis (LCH), diagnosed and treated in our department from June 1995 until May 1996, are described. The cases concern two neonates (one female and one male) born with necrotic lesions and skin nodules. The diagnosis was confirmed by skin biopsy which showed diffuse infiltration by CD1 antigen and S-100 protein positive histiocytes. The babies didn't present with anemia, hepatosplenomegaly or lymphadenopathy. Hepatic and renal function were normal. In both infants skeletal survey showed no lytic lesions but chest X-rays and high resolution computerized tomography (HRCT) scan revealed diffuse mottling of both lung fields. Bone marrow aspiration showed the presence of histiocytes in percentages of 6% and 10%, respectively. Both babies were treated with prednisolone 1 mg/kg body weight for three months. The first child who is 20 months old, is now well with resolution of skin and pulmonary lesions occurring within one month of the initiation of steroids, while the second, who presented spectacular resolution of skin lesions within the first three weeks of therapy, is also in excellent condition five months after completion of treatment. We conclude that congenital LCH has to be suspected in neonates with persisting skin lesions. If the disease is systemic but without organ dysfunction, treatment with steroids may be beneficial.