Lithium Treatment of Cyclic Hematopoiesis in the Gray Collie

Abstract

Cyclic hematopoiesis is a rare human disorder for which a remarkably close analogue exists in collie dogs. This disorder in the dog, variously named the “lethal grey syndrome,” the “grey collie syndrome,” “canine cyclic neutropenia,” and “canine cyclic hematopoiesis” is an autosomal recessive disease characterized by grey coat color, cyclic fluctuations in blood cell counts, recurrent infections, and premature death (Lund et al., 1967). Approximately 50% of these grey collies die from infections before they reach 3 weeks of age. Initial studies showed that the neutrophil counts cycled at 11 to 13 day intervals and that the distribution and survival of neutrophils in the circulation is normal (Dale et al., 1972b). Later studies showed that reticulocytes, platelets, lymphocytes, monocytes, and eosinophils also cycled with the same period length (although not in phase with one another) and suggested that varying marrow production of cells accounted for these fluctuations (Dale et al., 1972a; Patt et al., 1973). in human cyclic hematopoiesis, regular 21 day cycles of neutrophils, monocytes, lymphocytes, eosinophils, platelets, and reticulocytes also occur and the neutropenic periods are accompanied by local infections and considerable morbidity (Dale and Wolff, 1972; Guerry et al., 1973). The human defect likewise appears to reside in a periodic decrease of cell production by the marrow. Thus, we have proposed that a more thorough understanding of this model disease in the dog should provide insights into the mechanisms regulating marrow cell production in man.