X-LINKED AGAMMAGLOBULINEMIA, GROWTH-HORMONE DEFICIENCY AND DELAY OF GROWTH AND PUBERTY

Coinheritance of X-linked agammaglobulinemia and grow;h hormone defici ency (XLA/GHD) has been classified as an independent primary immune de ficiency. We evaluated the pattern of growth and endocrine function in seven XLA subjects (ages 10.9-20.1 years); four belonged to two diffe rent XLA pedigrees and three represented sporadic XLA cases. Three had reached adulthood (final stature 176.0, 173.5 and 165.0 cm, respectiv ely) and their retrospective growth showed delay in growth and puberty during adolescence. In the other four subjects, growth hormone produc tion was measured by growth hormone pharmacological stimulation tests (clonidine, arginine): three of four patients had insufficient growth hormone responses (peak growth hormone <10 mu g/l); all three had dela yed puberty; their growth hormone responses increased after ''priming' ' with testosterone, reaching values > 10 mu g/l in two of them and al lowing diagnosis of ''true'' growth hormone deficiency in the third. T he fourth was a normally growing subject who showed a normal growth ho rmone response both before and after testosterone priming. Six out of the seven subjects showed a growth pattern consistent with delay in gr owth and puberty. Our results suggest that true XLA/GHD is rarer than previously supposed and that subnormal responses to growth hormone sti mulation tests may be found without sex steroid priming of the test in adolescence. The most probable growth pattern in XLA appears to be de lay in growth and puberty, as has already been described for other chr onic diseases.