[Bone marrow lymphoid follicles in myelofibrosis compared with chronic myelogenous leukaemia (author's transl)]. / Les nodules lymphoïdes de la moelle dans la splénomégalie myéloïde: comparaison avec la leucémie myéloïde chronique.

The trephine bone marrow biopsies of 51 patients with myeloproliferative syndromes were revised searching for lymphoid follicles and lymphoplasmocytosis: 18 of these had idiopathic myelofibrosis and 33 chronic myelogenous leukaemia. Six of the 18 biopsies on patients with myelofibrosis showed lymphoid follicles but only one of the 33 with chronic meylogenous leukaemia did (P = 0.01, Fisher exact test). In addition, four of the six myelofibrosis having follicles had two or more of them. When the pathological pattern of myelofibrosis was considered according to the Lennert and al. classification we found significantly more follicles in the cellular phase of the disease than in the advanced phases (P = 00.4, Fisher exact test). These findings can be considered as a morphological argument supporting the idea of an immunological mechanism in the development of myelofibrosis.

CD34+ cell dose and CD33- subsets: collection and engraftment kinetics in autologous peripheral blood stem cells transplantation.

BACKGROUND AND OBJECTIVE: We analyzed the factors that affected the number and quality of peripheral blood stem cells (PBSC) collected for transplant in order to establish a minimum threshold for rapid hematopoietic recovery. DESIGN AND METHODS: From January 1995 to November 1996, a consecutive series of 67 patients, with hematologic and solid tumors underwent autologous PBSC transplantation. Collection of PBSC was performed after mobilization with granulocyte-colony stimulating factor (G-CSF) or with chemotherapy (CT) plus G-CSF. We calculated the factors that influenced PBSC collection, the kinetics of granulocyte and platelet recovery and the threshold value of CD34+ cells for a rapid recovery. The data were analyzed by means of multivariate Cox regression model and the receiver operating characteristic (ROC) methodology. RESULTS: Our results showed that mobilization with chemotherapy plus G-CSF was associated with a higher yield of PBSC in comparison with mobilization with G-CSF alone. Disease status, fewer cycles of conventional prior chemotherapy and absence of prior radiation therapy also influenced the yield of PBSC. The number of CD34+ cells, CD34+CD33- cell subsets, the mobilization schedule, and the conditioning regimen correlated significantly with time to hematopoietic recovery. In the multivariate analysis only the CD34+CD33- cell content and the total number of CD34+ were related with rapid neutrophil and platelet recovery, respectively. Use of G-CSF after transplant significantly shortened the neutrophil recovery time only in patients transplanted with suboptimal dose of PBSC. INTERPRETATION AND CONCLUSIONS: These data suggest the utility of quantitation of CD34+ cells subsets to predict quick engraftment.