Reconstitution of the T cell receptor alpha beta repertoire in recipients of allogeneic BMT.

This report describes the qualitative analysis of T cell receptor (TCR) repertoire regeneration in recipients of BMT. RNA samples from patient and control peripheral blood lymphocytes were prepared and tested for the presence of multiple V alpha and V beta transcripts by the polymerase chain reaction. TCR V gene expression was highly diverse within the first 6 months post-transplantation in recipients receiving either T cell-depleted or T cell-replete marrow, and in HLA mismatched as well as matched donor-recipient pairs. The sequencing of TCR message from BMT recipients also demonstrated J gene diversity and apparently normal junctional diversity at the V-J alpha join. Thus, T cell pools in BMT recipients are largely heterogeneous, not mono- or oligoclonal.

Cytologic diagnosis of respiratory syncytial virus infection in a bronchoalveolar lavage specimen from a bone marrow transplant recipient.

Cytologic examination of a bronchoalveolar lavage specimen from a 6-year-old bone marrow transplant recipient revealed pulmonary infiltrates and occasional cells containing discrete pink cytoplasmic inclusions on a May-Grunwald-Giemsa stain. Direct immunofluorescence stains of cytospins prepared from the same specimen were positive for respiratory syncytial virus (RSV). Electron microscopy revealed occasional epithelial cells with cytoplasmic inclusions composed of filamentous virions. The patient died 6 months after the specimen was taken. An autopsy showed ongoing bronchiolitis with diffuse alveolar damage. Occasional bronchiolar epithelial cells contained discrete eosinophilic cytoplasmic inclusions, which on ultrastructural examination proved to be compatible with RSV. Examination of bronchoalveolar lavage fluid from bone marrow transplant recipients should include a search for cytopathic changes compatible with RSV infection. Electron microscopy can be helpful in confirming this diagnosis.

Avascular femoral head necrosis in pediatric cancer patients.

Avascular femoral head necrosis was identified in 15 patients treated at a major pediatric oncology center from 1974 to 1991. The predominant underlying diagnosis was acute leukemia (lymphoblastic, n = 6; non-lymphoblastic, n = 2); two patients had chronic myeloid leukemia, two Hodgkin's disease, and three other solid tumors. Patients ranged from 7 to 27 years of age at diagnosis of this complication, with a median interval of 25 months (range, 0-11 years) from primary diagnosis. Both steroids and radiation therapy appear implicated in the pathogenesis of avascular necrosis: nine patients had received high cumulative doses of prednisone (3.4-14 g/m2), four had received 35-64.8 Gy local irradiation involving the femoral head, and one underwent total body irradiation (12 Gy). Of the 11 surviving patients, six are asymptomatic and fully active. Two patients have joint pain that is responsive to conservative measures. Severe pain and joint deterioration necessitated arthroplasty in two cases, and a third child is undergoing orthopedic evaluation because of worsening symptoms. Thus, like adult cancer patients, children who receive high doses of steroids or local irradiation involving femoral heads are at risk for avascular necrosis. In patients with chronic myeloid leukemia, the complication may be disease related. Although outcomes in our series are better than those reported in adults, the long period of risk for these children and young adults precludes definitive conclusions.