POSSIBLE VIRUS IN SCHIZOPHRENIA AND SOME NEUROLOGICAL DISORDERS
Specimens Throat swabs, faeces, paired sera, and a sample of c.s.F. collected from patients diagnosed as schizophrenic. From the other patients, only C.S.F. was obtained. At first all specimens, except faeces, were tested before freezing. Later, frozen specimens were tested (see below). Specimens from other hospitals were collected and transported to Northwick Park in liquid nitrogen. were
D. A. T.
R. P. PARRY EVE JOHNSTONE I. N. FERRIER
J. TYRRELL J. CROW
Divisions of Communicable Diseases and Psychiatry, Clinical Research Centre, Northwick Park Hospital, Harrow, Middlesex HA1 3UJ
Cerebrospinal fluid from 13 of 38 patients with schizophrenia had a cytopathic effect in cultures of MRC5 cells. The cytopathic agent passed a 100 nm but not a 50 nm filter and was unaffected by heat at 56°C for 30 min, treatment with chloroform, or the presence in cultures of bromodeoxyuridine. The agent could not be propagated serially in a satisfactory manner but its properties were those of a virus. A similar cytopathic effect was induced by cerebrospinal fluid from 8 of 11 patients with serious or chronic nervous system disease but only 1 of 25 patients with surgical or general medical conditions. Summary
Introduction SCHIZOPHRENIC symptoms have occurred during illwith neurological signs and cerebrospinal fluid (c.s.F.) changes which suggested an encephalitic process. 1-4 Such symptoms were common in the wake of the encephalitis lethargica epidemics-7 and were associated with Vilyuisk encephalitis in the Yakat Republic of the U.S.S.R.8 As in Creutzfeldt-Jakob disease and subacute sclerosing panencephalitis, slow virus infections of the nervous system may present with a clinical picture which includes mental disturbance and is quite unlike that of acute encephalitis. Moreover, changes in the c.s.F. in some patients with schizophrenia9 are consistent with the possibility of chronic infection. We thought it possible that some psychoses might be rare manifestations of a common virus infection and decided to look for common viruses in c.s.F. from patients with acute schizophrenia. Unexpectedly we found evidence of an unusual agent. nesses
Specimens from schizophrenic patients were inoculated into roller-tube cultures of the MRC5 strain of human lung fibroblasts and 0-HeLa cells in 2% fetal bovine serum (F.B.S.) in Eagle’s basal medium, and into secondary rhesus-monkey kidney cells in 1% F.B.s. in medium 199. The cultures were incubated in a roller drum at 33°C and examined regularly for cytopathic effects. These methods were later modified as described below. Results Viruses were isolated from the throat of 5 patients with schizophrenia (table I). They were species commonly found there. No virus was isolated from fseces or from c.s.F. (poliovirus 3 was obtained from two c.s.F. TABLE I-ISOLATED VIRUSES AND C.P.E. OF C.S.F. FROM PSYCHOTIC PATIENTS
Patients and Methods Patients We studied patients admitted with a diagnosis of schizoand patients with a variety of other conditions admitted to this district general hospital, and patients admitted to The London Hospital, the National Hospital for Nervous Diseases, London, and the Southern General Hospital, Glasgow, who needed lumbar puncture. The patients are described in detail in a subsequent paper. 10
*Fxces from this patient also had a C.P.E. Patients from whom no viruses were isolated C.P.E. are not shown.
specimens but was almost certainly a laboratory minant). No serum contained interferon. However, in cultures inoculated with
pathic effect (C.P.E.) like that induced by virus was often seen, particularly in MRC5 cells. C.P.E. The
of C.S.F. C.P.E. was
first in small foci
cells became distorted and granular and eventually detached from the glass or degenerated into debris. The effect was often seen within one or two days of inoculation. It was reminiscent of a slowly progressive c.P.E. produced by picornaviruses such as rhinoviruses. In early experiments the effect was limited and after a few days the cultures appeared normal. The effect was seen in all three types of cells but it was most frequently and easily seen in MRC5 fibroblasts. c.s.F. from 13 of 38 schizophrenic patients and faeces from schizophrenic patients had a C.P.E. The degree of cell destruction varied, and sometimes the C.P.E. was sufficient to destroy the whole culture. Repeated attempts were made to transmit the effect to other cultures but this was successful with only one specimen and even then only once. We therefore compared the c.p.E. produced by several different positive c.s.F. samples after various modifications of the culture technique. The effect was enhanced if cultures were kept for a few days in maintenance medium, were not changed on the day of inoculation, and were kept stationary thereafter. Ham’s medium F12K (Kaighn’s modification) also enhanced c.P.E.S in some experiments. Under these conditions the C.P.E. of one c.s.F. specimen was passed through three cultures. The C.P.E. was reduced if the medium contained 10% F.B.s. but incubation at 300C made little difference. The Vero and V3 continuous lines of monkey kidney cells and a cultured grade 2-3 glioma (43/78) were insensitive to killing by c.s.F., but C.P.E.S were typical in cultures of fetal brain, another grade 2-3 glioma (32/78), and a medulloblastoma (RF). In 32/78 cells the C.P.E.S of c.s.F. from patient 34 and a patient with possible Huntington’s chorea were passed through two and three cultures, respectively, over a period of about three weeks. There was no apparent growth in organ cultures of fetal brain. A C.P.E. was seen in only four of seven cloned strains of human embryo lung cells. In general, the appearance of the degenerating cells was similar after the inoculation of all positive c.s.F. specimens. But the extent of C.P.E. varied considerably between patients (figure) and between types of cultured cell.
Some Properties of the Agent c.s.F. was diluted about 1/10
effect in cultures of MRC5 cells after inoculation of C.S.F. from two psychotic patients.
Unstained (xabout 120) Top: uninoculated cells; middle: a small focus with a few rounded cells and a bare area from which cells have been lost (case 28); bottom: extensive and generalised cytopathic effect
in medium and filtered, and 1 ml was inoculated into MRC5 cultures. The results (table n) suggest that the effect is associated with a particle of diameter < 100 nm. The effects on C.P.E. of heating c.s.F. at 56°C or treating it overnight with 20% chloroform showed the agent to be rather heat stable and solvent resistant. 5 of 8 cytopathogenic specimens became inactive after a month or more at -40°C but it was possible to produce C.P.E. with c.s.F. which had been frozen and stored for long periods at -70°C or in liquid nitrogen and which had been thawed and frozen again. To gain some idea of whether the genome of the putative virus was R.N.A. or D.N.A., C.S.F. was inoculated into cultures containing 40 tg,/ml bromodeoxyuridine (B.U.D.R.). C.P.E.S appeared simultaneously in B.U.D.R.-treated and untreated cultures and control tests showed that the c.P.E. of herpes simplex (a D.N.A. virus) was inhibited in treated cultures while that of an echovirus (an R.S..t
virus) was not. We considered the
841 or undiagnosed neurological disease (including Huntington’s chorea and multiple sclerosis) (table ill). These patients are described in detail in the subsequent
TABLE II-EFFECT OF TREATMENT ON C.P.E. OF C.S.F. FROM
SCHIZOPHRENIA, HUNTINGTON’S CHOREA, AND MULTIPLE SCLEROSIS
*This specimen was centrifuged at 100 000 g for cytopathic but the supernatant was not. fTest not repeated owing to lack of material. K.D.. not
h; the deposit
caused by a mycoplasma or virus carried by the cultures. Two cultures in which the C.P.E. was extensive were cultured for mycoplasmas; there was a light growth of Mycoplasma orale which was also found in a control culture. The c.P.E. was not inhibited by the antimycoplasma drug tylosin (50 ug,/ml), or by treating with chloroform. Uninoculated cultures were maintained in parallel with all inoculated cultures and were passed with them, but no c.P.E.was ever seen. We thus concluded that the C.P.E. was not due to a contaminating agent and that the c.s.F. of about one third of our series of schizophrenic patients contained a virus-like agent.
Other patients Stationary cultures of MRC5 or glioma cells in which the medium was not changed after inoculation were maintained at 33°C after inoculation with c.s.F. from patients under investigation or treatment of various medical and surgical conditions. Cells cultured in these conditions were among the most sensitive to C.P.E.S A c.P.E. was produced by C.S.F. from only 1 of 25 patients who either had no neurological disease or had acute meningitis or febrile convulsions. However, a C.P.E. was induced by c.s.F. from 8 of 11 patients with
We have considered critically how to interpret these phenomena. The C.P.E. can be very localised and transient, and may vary in extent from test to test, presumably because there are subtle differences in the state of the cultures; nevertheless if attention is given to the technique the effect is basically repeatable-some c.s.F. samples have produced C.P.E.S on retesting up to six times and Dr M. S. Pereira (Virus Reference Laboratory, Central Public Health Laboratory, Colindale), has also found that some of our material has a "rhinoviruslike" C.P.E. which she failed to transmit. The c.P.E. appears to be due to an agent which replicates because in certain experiments it starts in one or two foci and then spreads, over perhaps a week, until all the cells are killed. Nevertheless passage is difficult, and although we have succeeded on some occasions with improved techniques we cannot yet produce enough material to study the agent propagated in vitro. The agent passes a 100 nm filter but not one of 50 nm, is presumably lipid free, and possibly contains infectious R.N.A. It is too large and too labile to be like the scrapie agent and its properties do not correspond to,any virus which we know is found in the human central nervous system. It cannot be a mycoplasma because it is chloroform stable and resists treatment with tylosin. Although we appear to be dealing with one infectious agent our characterisation is so incomplete that there could be several different organisms or several serotypes of the same organism. The one positive fxces suggests that there may be transmission by the fsecal-oral route. The agent seems to be distinct from the agent apparently isolated by Mitchell et al. 11 from the bone-marrow of patients with multiple sclerosis. Although Russian and other workers have described the detection of toxic and viral substances in the blood and C.S.F. of patients with schizophrenial2 we are unconvinced by their data which did not include the results of testing in tissue culture. We thank Mrs C. Allen, Mr J. Parry, Ms M. Sergeant, and Mr S. Gamble for assistance, Mr D. G. T. Thomas and Mr J. Darling for supplying cells and C.S.F., Mr J. Clarke for photomicrographs, PtofesW. B. Jennett, Dr E. Teasdale, Dr P. Sanderson, Dr P. Rudge, Dr D. Webster, and Dr M. J. Swash for supplying C.S.F. samples from patients with non-psychiatric disease, and Dr N. Yorkstone for help in organising an earlier investigation which was unsuccessful. We thank Dr D. Taylor-Robinson and Miss P. Furr for the mycoplasma tests. sor
TABLE III-C.P.E. OF C.S.F. FROM PATIENTS WITHOUT PSYCHOSIS
Requests for reprints should be addressed to D.A.J.T. REFERENCES 1. Sobin, A., Ozer, M. N J Mt Sinai Hosp. 1966, 33, 73. 2. Himmelhoch, J., Pincus, J., Tucker, G., Detre, T. Br. J. Psychiat. 531.
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’Posmve result in an elderly African male with unexplained back and a normal radiculogram who recovered undiagnosed. F:gum in parentheses are numbers of patients tested. ’the 12 schizophrenic patients were tested in parallel with the xhtzophrenic patients.