Lymphoproliferative disease of granular lymphocytes (LDGL) is a heterogeneous disorder and the pathogenesis is likely to be complex. Some patients with chronic active EBV (CAEBV) infection also have LDGL. To investigate the relationship between EBY infection and the pathogenesis of LDGL, we conducted a survey for EBV DNA sequences by Southern blot analysis of DNA obtained from the peripheral blood of seven patients with LDGL including one with CAEBV infection.

The effect of long-term inhaled steroid therapy on linear growth in asthmatic children is still a point of controversy. We tried to clarify the effect of long-term treatment with inhaled beclomethasone dipropionate (BDP) on linear growth and final height of asthmatic children. Height data measured annually from 12 years (beginning at age 10 years in most patients) to 20 years of age were retrospectively collected from clinical records in 97 moderate to severe asthmatics (49 boys, 48 girls) born in 1971-1975 who were observed regularly for more than 8 years at our outpatient clinic. Data were expressed as standard deviation scores and were compared between patients treated with BDP (30 boys and 31 girls, mean daily dosages were 300-800 microg) and without BDP. Growth delay in the early period of puberty and catch-up growth in the late period of puberty was found in both patients treated with and without BDP. The age of onset of treatment with BDP inhalation had no influence on linear growth, and asthmatic children receiving optimum treatment eventually attained standard final height for their age group. Long-term treatment with inhaled BDP in conventional doses does not significantly impair linear growth in asthmatic children.

Neonates with Down's syndrome occasionally show an excess of blasts in their peripheral blood. This disorder spontaneously resolves within several months and is called transient abnormal myelopoiesis (TAM) or transient myeloproliferative disorder. It has been uncertain whether the excess of blasts in TAM is a result of a clonal proliferation or a polyclonal reactive condition. The clonality of cells in females can be examined by analysis of the methylation patterns of the X chromosomes of proliferating cells using restriction fragment length polymorphism (RFLP). Using this strategy, we studied three females with Down's syndrome accompanied by TAM who showed heterozygosity in RFLP of either the hypoxanthine phosphoribosyltransferase or phosphoglycerate kinase gene. Analysis of the methylation patterns of these genes demonstrated a clonal nature for blasts in three patients. Thus, TAM is a clonal proliferative disorder. In addition, lymphocytes with a normal appearance contained in analyzed samples from these patients also showed a monoclonal pattern, suggesting that TAM may be a disorder of multipotent stem cells.

Neonates with Down's syndrome occasionally show an excess of blasts in their peripheral blood. This disorder spontaneously resolves within several months and is called transient abnormal myelopoiesis (TAM) or transient myeloproliferative disorder. It has been uncertain whether the excess of blasts in TAM is a result of a clonal proliferation or a polyclonal reactive condition. The clonality of cells in females can be examined by analysis of the methylation patterns of the X chromosomes of proliferating cells using restriction fragment length polymorphism (RFLP). Using this strategy, we studied three females with Down's syndrome accompanied by TAM who showed heterozygosity in RFLP of either the hypoxanthine phosphoribosyltransferase or phosphoglycerate kinase gene. Analysis of the methylation patterns of these genes demonstrated a clonal nature for blasts in three patients. Thus, TAM is a clonal proliferative disorder. In addition, lymphocytes with a normal appearance contained in analyzed samples from these patients also showed a monoclonal pattern, suggesting that TAM may be a disorder of multipotent stem cells.

No abstract