[Lymphocytes in the human brain]

There are different concepts of the role of lymphocytes in the brain of schizophrenics available in the literature (they are considered as manifestations of encephalitis or as an allergic reaction, etc.). Autopsy of 350 schizophrenics and 16 mentally healthy subjects who died at the age of 15 to 87 years revealed the constant (nearly in 90 percent of the cases) presence of sparse segmentary clusters of small lymphocytes in the adventitial vessels in the medulla oblongata irrespective of the death causes. The biological role of lymphocytes in the brain is discussed, particularly, in terms of immunologic tolerance manifestations.