976 MULTIPLE-SCLEROSIS-ASSOCIATED AGENT
TABLE II-RESPONSE OF CIRCULATING MOUSE P.M.N. AFTER
INJECTION
SIR,-Koldovsky, Henle, and their colleagues1.2 indicatedthat a factor in multiple sclerosis (M.S.) brain depressed mouse circulating polymorphonuclear cells (P.M.N.S) after intraperitoneal injection. This agent seemed to be transmissible from mouse to mouse and was called the M.s.-associated antigen (M.S.A.A.). These reports seemed to confirm the work of Carp et al .,3 and The Lancet suggested that the cause of M.S. had been found.4 The initial findings were not confirmed by Brown and Gajdusek5 or McNeil et al.6 who found no P.M.N. depression in association with M.S. samples. Dr Kies and Dr Ames (Oct. 15, p. 814) have also reported failure, and Dr Carp, Dr Koldovsky, and Dr Henle and their colleagues (Oct. 15, p. 814), while reaffirming the validity of their published experiments, say that the P.M.N. assay is "too erratic to be useful". We have done studies using coded, well-documented brain specimens, to determine if we could differentiate M.S. patients from others with other neurological disease and normal controls using the mouse P.M.N. depression techniques described
OF BRAIN SAMPLES FROM M.S.
NEUROLOGICAL
PATIENTS,
OTHER
DISEASE, AND CONTROLS
now
by Koldovsky et al.’.1. Two sets of coded samples were studied. Both were obtained from W. W. T. who held the code until the studies were completed. The specimens were homogenised in phosphate-buffered saline to yield a 20% suspension, and, after clarification at low-speed centrifugation, the supernatant was frozen at —70°C. Mice used in this portion of the study (C57B and TABLE I-RESPONSE OF CIRCULATING MOUSE P.M.N. AFTER INTRAPERITONEAL
INJECTION OF
BRAIN SAMPLES FROM M.S.
PATIENTS AND CONTROLS
S.S.P.E.
=
subacute sclerosing panencephalitis.
later. Depression of r.r.t.rt.s was observed in mice inoculated with specimens from one M.S. patient after 4 and 14 days, and one control patient 4 days after injection. The same control was not positive on both tests. The results of the second set of coded specimens are presented in table u. Specimens from one of three M.S. patients were associated with a P.M.N. depression. Mice inoculated with the specimen from a patient with Alzheimer’s disease also had a depression in P.M.N.s. Mice inoculated with a suspension of brain from a patient with S.S.P.E., a patient with Parkinson’s disease, and three controls did not depress the P.M.N. count We conclude that there was no consistent association between inoculation of mice with M.S. tissue and the level of From our experience, P.M.N. depression, transient and random. We believe that controls were adequate provided and that all possible precautions were taken to avoid variation.
circulating when it
P.M.N.S.
occurred,
was
Infectious Diseases Branch, I.R.P., National Institute of Neurological and Communicative Disorders and Stroke National Institutes of Health Bethesda, Maryland 20014, U.S.A.
DAVID L. MADDEN AURELLA G. KREZLEWICZ MANETH GRAVELL JOHN L. SEVER
Neurology Service,
Yes=depression of circulating P.M.N. 20% t No = depression of circulating P.M.N.
TABLE II-RESPONSE OF CIRCULATING MOUSE P.M.N. AFTER
INJECTION
SIR,-Koldovsky, Henle, and their colleagues1.2 indicatedthat a factor in multiple sclerosis (M.S.) brain depressed mouse circulating polymorphonuclear cells (P.M.N.S) after intraperitoneal injection. This agent seemed to be transmissible from mouse to mouse and was called the M.s.-associated antigen (M.S.A.A.). These reports seemed to confirm the work of Carp et al .,3 and The Lancet suggested that the cause of M.S. had been found.4 The initial findings were not confirmed by Brown and Gajdusek5 or McNeil et al.6 who found no P.M.N. depression in association with M.S. samples. Dr Kies and Dr Ames (Oct. 15, p. 814) have also reported failure, and Dr Carp, Dr Koldovsky, and Dr Henle and their colleagues (Oct. 15, p. 814), while reaffirming the validity of their published experiments, say that the P.M.N. assay is "too erratic to be useful". We have done studies using coded, well-documented brain specimens, to determine if we could differentiate M.S. patients from others with other neurological disease and normal controls using the mouse P.M.N. depression techniques described
OF BRAIN SAMPLES FROM M.S.
NEUROLOGICAL
PATIENTS,
OTHER
DISEASE, AND CONTROLS
now
by Koldovsky et al.’.1. Two sets of coded samples were studied. Both were obtained from W. W. T. who held the code until the studies were completed. The specimens were homogenised in phosphate-buffered saline to yield a 20% suspension, and, after clarification at low-speed centrifugation, the supernatant was frozen at —70°C. Mice used in this portion of the study (C57B and TABLE I-RESPONSE OF CIRCULATING MOUSE P.M.N. AFTER INTRAPERITONEAL
INJECTION OF
BRAIN SAMPLES FROM M.S.
PATIENTS AND CONTROLS
S.S.P.E.
=
subacute sclerosing panencephalitis.
later. Depression of r.r.t.rt.s was observed in mice inoculated with specimens from one M.S. patient after 4 and 14 days, and one control patient 4 days after injection. The same control was not positive on both tests. The results of the second set of coded specimens are presented in table u. Specimens from one of three M.S. patients were associated with a P.M.N. depression. Mice inoculated with the specimen from a patient with Alzheimer’s disease also had a depression in P.M.N.s. Mice inoculated with a suspension of brain from a patient with S.S.P.E., a patient with Parkinson’s disease, and three controls did not depress the P.M.N. count We conclude that there was no consistent association between inoculation of mice with M.S. tissue and the level of From our experience, P.M.N. depression, transient and random. We believe that controls were adequate provided and that all possible precautions were taken to avoid variation.
circulating when it
P.M.N.S.
occurred,
was
Infectious Diseases Branch, I.R.P., National Institute of Neurological and Communicative Disorders and Stroke National Institutes of Health Bethesda, Maryland 20014, U.S.A.
DAVID L. MADDEN AURELLA G. KREZLEWICZ MANETH GRAVELL JOHN L. SEVER
Neurology Service,
Yes=depression of circulating P.M.N. 20% t No = depression of circulating P.M.N.
