Leukocyte subpopulations in cerebrospinal fluid of normal rabbits

Cerebrospinal fluid leukocytes from 48 apparently healthy New Zealand white rabbits were examined to define the number and types of cells present. The cerebrospinal fluid contained 0 to 7 leukocytes/mm3 (median 3/mm3). This small pool of mononuclear cells was comprised of 40 to 79% lymphocytes (median 67%) and 21 to 60% monocytes (median 33%). T lymphocytes were the predominant cell type, outnumbering B cells by approximately 100 to 1. In contrast to cerebrospinal fluid, normal rabbit blood contained nearly equal proportions of B and T cells (median 39% and 46% of lymphocytes, respectively). Three cerebrospinal fluid samples from apparently healthy rabbits had greater than 20 leukocytes/mm3.