CD4 and Chylothorax: Data indicated that while the overall cellularity of chyle, particularly the absolute numbers of T-cell subsets (T lymphocytes (CD3+), Helper/inducer T lymphocytes (CD3+CD4+) and Suppressor/cytotoxic T lymphocytes (CD3+CD8+)), was significantly higher in acquired chylothorax, the relative proportions (percentages) of most lymphocyte subsets and the levels of immunoglobulins were largely similar between congenital and acquired chylothorax.