title: Letter: B lymphocytes during ageing.
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging; D001402:B-Lymphocytes / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007128:Immunoglobulin Fragments / Q000302:isolation & purification; D007075:Immunoglobulin M / Q000302:isolation & purification; D007223:Infant; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D007128:Immunoglobulin Fragments; D007075:Immunoglobulin M