1062 T-LYMPHOCYTE DEFICIENCY IN DOWN SYNDROME
SIR,-Dr Whittingham and her colleagues (Jan. 22, p. 163) suggests that the immunodeficiency in patients with Down syndrome is "accompanied, or even caused, by a heavy load of infections early in life, because of incapacity to maintain adequate standards of personal hygiene due to mental retardation and crowding". This hypothesis seems to accord with our find-
ings of progressively declining lymphocyte responsiveness
to
phytohaemagglutinin, starting at about 10-15 years of age, in patients with Down syndrome;however, Dr Whittingham and her colleagues’ hypothesis appears to be seriously challenged by the finding of a reduced percentage and absolute number of circulating T lymphocytes in infants and even newborn babies who
trisomic for chromosome 21.2-° To test this hypothesis further we assessed the percentage of circulating lymphocytes forming rosettes with sheep erythrocytes (E rosettes) in fourteen patients with Down syndrome aged 4 months to 3 years and in fourteen age and sex matched chromosomally normal children with cerebral palsy attributable to perinatal cerebral anoxia; all were living at home and being cared for by their mothers. The E-rosette test technique is described elsewhere.’The E-rosette percentages (mean + s.D., and range) were 45-3+6-0 (36-57) for Down syndrome and 667±7.9 (53-77) for the controls (P
SIR,-Dr Whittingham and her colleagues (Jan. 22, p. 163) suggests that the immunodeficiency in patients with Down syndrome is "accompanied, or even caused, by a heavy load of infections early in life, because of incapacity to maintain adequate standards of personal hygiene due to mental retardation and crowding". This hypothesis seems to accord with our find-
ings of progressively declining lymphocyte responsiveness
to
phytohaemagglutinin, starting at about 10-15 years of age, in patients with Down syndrome;however, Dr Whittingham and her colleagues’ hypothesis appears to be seriously challenged by the finding of a reduced percentage and absolute number of circulating T lymphocytes in infants and even newborn babies who
trisomic for chromosome 21.2-° To test this hypothesis further we assessed the percentage of circulating lymphocytes forming rosettes with sheep erythrocytes (E rosettes) in fourteen patients with Down syndrome aged 4 months to 3 years and in fourteen age and sex matched chromosomally normal children with cerebral palsy attributable to perinatal cerebral anoxia; all were living at home and being cared for by their mothers. The E-rosette test technique is described elsewhere.’The E-rosette percentages (mean + s.D., and range) were 45-3+6-0 (36-57) for Down syndrome and 667±7.9 (53-77) for the controls (P
