Abnormal NK cell lymphocytosis detected after splenectomy: association with repeated infections,relapsing neutropenia,and persistent polyclonal B-cell proliferation

We report the case of a boy with hereditary spherocytosis who presented with mild microcytic hypochromic anemia and recurrent leg ulcers that had been present since childhood. Chronic natural killer (NK) cell and B-cell lymphocytosis was detected 1 year after therapeutic splenectomy during investigation of recurrent episodes of neutropenia and persistent lymphocytosis. NK cells proved to be abnormal at immunophenotyping studies, and B-cells were polyclonal and displayed a normal immunophenotype. Genotypic analysis of T-cell receptor (TCR)-β and TCR-γ genes showed a germ-line pattern. The clinical course of this patient was characterized by multiple pulmonary infections and amygdalitis. We discuss the potential roles of persistent immune stimulation due to chronic hemolysis and severe leg ulcers and of splenectomy in the origin of NK cell lymphocytosis and the relationship between NK cells and recurrent infections, relapsing neutropenia, and polyclonal B-cell response.Int J Hematol. 2002;75:484–488.     

Giardia spp. and Cryptosporidium spp. In the Ivaí Indigenous Land, Brazil

The objective of this study was to investigate the occurrence of cysts of Giardia spp. and oocysts of Cryptosporidium spp. in waters of the Ivaí Indigenous Land, Brazil. Samples of river and spring water and of treated water were filtered and analyzed by direct immunofluorescence (Merifluor kit, Meridian Bioscience, Cincinnati, Ohio). Of 21 samples, 7 from each locality, 3 (3/7, 42.8%) from a river were positive for Giardia (mean concentration 2.57 cysts/L), and 1 (1/7, 14.3%) was positive for Cryptosporidium (6 oocysts/L). From springs, 1 sample (1/7, 14.3%) was positive for Cryptosporidium (6 oocysts/L). One sample (1/7, 14.3%) from treated water was positive for both, with 4 oocysts/L and 2 cysts/L. Giardia was the more frequent protozoan present.