Human herpesvirus-8 serology in pediatric organ transplantation.

Human herpesvirus (HHV)-8 has been demonstrated to be involved in the pathogenesis of Kaposi's sarcoma, body cavity lymphomas, multicentric Castleman disease, and, more recently, acute bone marrow failure. In order to study the correlation between HHV-8 and immunosuppression, we performed a serological study in a group of 28 pediatric heart and heart-lung transplant recipients; of mean age 11.5 +/- 2.5 years. We analyzed blood samples prior to, at 3 to 6 months, and at least 12 months after transplantation. All patients were negative pretransplantation. We observed 10 seroconversions: one patient at 6 months; two patients at 12 months; and seven within the third year after transplantation. Our preliminary data demonstrated that HHV-8 seroconversion is frequent among pediatric transplant recipients. It was probably related to the length of immunosuppression rather than the organ transplantation; Serological assays of all donor specimens of seroconverted patients were negative.

[PTPN11 gene mutation in LEOPARD syndrome]. / Mutazione del gene PTPN11 nella sindrome LEOPARD.

The multiple lentigines/LEOPARD syndrome (ML/LS) is a rare and complex genetic syndrome. It is an autosomal dominant disorder with a variable expressivity. The syndrome is mainly characterised by growth retardation, multiple lentigines, and congenital heart diseases with electrocardiographic anomalies, dysmorphia of the face and deafness. The incidence of this pathology is still unknown and a familial inheritance is present in 70% of cases. Some of the ML/LS clinical features are the same as those of the Noonan syndrome (NS), such as congenital cardiac abnormalities, dysmorphia and growth retardation. NS and ML/LS are caused by allele mutations of the PTPN11 gene. We report the case of a 3-year-old girl, who was observed for the presence of widespread lentigines, a 1/6-protosystolic murmur at the mesocardium and growth retardation. The diagnosis of ML/LS was made and thus a molecular analysis of the PTPN11 gene was carried out, directly sequencing the codifying region. The molecular analysis revealed a missense mutation (A836G) in hexone 7 (TYR279CYS) of the PTPNII gene. This mutation is has been observed, at present, in a few cases of ML/LS and Noonan syndrome.