T-cell alterations in late postpoliomyelitis.

The immunologic status of patients with prior poliomyelitis was studied using two-color flow cytometric analyses. Ten lymphocyte subsets including subsets of CD4+ T cells, CD8+ T cells, B cells, and natural killer cells were examined. Eighteen patients presented with clinical symptoms compatible with the postpolio syndrome. This group was compared with 18 asymptomatic postpolio survivors and 22 age-matched healthy controls. The results demonstrated significant alterations in CD4+ subsets in the postpolio group as a whole when compared with normal controls. These findings reveal definite alterations in the immune status of postpolio survivors and raise the possibility that immunologic factors may contribute to late disease progression.

Fluctuations of CD4+ T-cell subsets in remitting-relapsing multiple sclerosis.

Patients with multiple sclerosis (MS) frequently have selective depletion of the CD45R+CD4+ T-cell subset during active phases of disease. To study the relationship between changes in this subset and the onset of objective clinical exacerbations of disease, a longitudinal study was undertaken. Two CD4+ T-cell subsets and two CD8+ T-cell subsets were monitored by two-color immunofluorescence using a fluorescence-activated cell sorter. These subsets of peripheral blood lymphocytes were monitored monthly for one year in a group of 9 patients with remitting-relapsing MS and in 11 healthy age-matched control subjects. Significant changes in the ratio of two CD4+ T-cell subsets (CD45R-/CD45R+) were detected in 7 of 9 patients with MS, but not in any of the control subjects. Of those 7 persons, 4 suffered major clinical relapses substantiated by alterations in the neurological examination. The other 3 suffered minor relapses with subjective clinical abnormalities. All 7 had increased CD4+ T-cell subset ratios (%CD4+CD45R-/%CD4+CD45R+) within the month that new symptoms were reported. Most such increases resulted from a simultaneous depletion in the number of CD45R+CD4+ T cells and an increase in the number of CD45R-CD4+ T cells. One patient suffered a major relapse with no change in the ratio of CD4+ subsets but had a depletion of all CD4+ T cells. There were no consistent changes in any of the other subsets measured. These results indicate that a subgroup of patients with MS have abnormal fluctuations of two CD4+ T-cell subsets, which may correlate with increased disease activity.

Selective loss of a subset of T helper cells in active multiple sclerosis.

Patients with active multiple sclerosis (MS) have a selective loss of a subset of T helper cells (Th), detectable by two-color fluorescence-activated cell sorter analysis of peripheral blood lymphocytes. By using pairs of monoclonal antibodies to the T-cell subset markers CD4 (Th) and CD8 [T suppressor/cytotoxic cell (Ts)] and the common leukocyte markers Lp220 and Lp95-150, five phenotypically distinct T-cell subsets have been identified in peripheral blood: two CD4+ Th cell subsets and three CD8+ Ts cell subsets. The frequencies and absolute numbers of these five populations were measured in patients with active and inactive MS and were compared with those in healthy age-matched controls and in patients with other neurologic diseases. A high frequency of patients with active MS (80%) had a selective reduction of one Th subset (CD4+ Lp220+) compared with normal controls (P less than 0.001) or patients with inactive MS (P less than 0.001). Three patients examined sequentially had a further loss of the Lp220+ Th subset as disease activity progressed. The proportion of two Ts subsets was also abnormal in patients with active MS, but this defect was not restricted to that group. Total Th and Ts cell frequencies and Th/Ts ratios were not significantly different between patient and normal control groups. Thus, two-color analysis of T-cell subsets may be a more sensitive indicator than conventional single-marker assays of abnormal immune status in MS patients.

Viral antibodies in cerebrospinal fluid of multiple sclerosis and control patients: comparison between radioimmunoassay and conventional techniques.

Cerebrospinal fluid antibodies to measles, rubella, vaccinia, herpes simplex, and varicella-zoster viruses in four patient study groups (clinically definite multiple sclerosis [MS], early probable MS, optic neuritis, and control patients with other neurological diseases) were assayed by radioimmunoassay, complement fixation, hemagglutination-inhibition, or complement-enhanced plaque reduction methods. Antibodies were more frequently found and at higher dilutions by radioimmunoassay than by other techniques. Measles virus antibody, the most frequently found antibody, was present in the cerebrospinal fluid of 72% of MS patients and 5% of control patients. The differences between the numbers of MS patients and control patients with antibodies to other viruses were not as marked. Thus, 58% of MS patients versus 21% of control patients had antibody to rubella virus, 20 versus 3% had antibody to vaccinia virus, 50 versus 33% had antibody to herpes simplex virus, and 25 versus 8% had antibody to varicella virus. Sixty-seven percent of MS patients and 26% of control patients had antibodies to two or more viruses in their cerebrospinal fluid.

Effect of cyclophosphamide in vitro and on vaccinia virus replication in tissue culture.

The effect of cyclophosphamide on the growth of Vero, BSC-1, and HeLa cells in monolayer cultures was studied. By using hemocytometer counts and tritiated thymidine uptake as indicators of growth, it was found that cyclophosphamide significantly interfered with the metabolism of Vero and BSC-1 cells when sustained in Leibovitz medium. Vero cells and HeLa cells grown in Eagle medium were not affected by exposure to cyclophosphamide. Vaccinia virus replication in Vero cell monolayer cultures incubated with cyclophosphamide was markedly augmented, and this enhanced growth was reflected by virus quantitation techniques and metabolic studies using tritiated thymidine uptake. No difference in the distribution of infectious particles was found when cyclophosphamide-treated and control infected cultures were compared. Pathways other than through hepatic enzymes appear available to activate cyclophosphamide in vitro. These effects are dependent on both the cell type and the medium in which the cells are grown. Cyclophosphamide can facilitate vaccinia virus replication in vitro through metabolic interactions at the cellular level. The precise mechanisms underlying this effect require further study.

Antibodies to vaccinia and measles viruses in multiple sclerosis patients.

A virologic comparison was made of 144 patients with multiple sclerosis, 34 of their healthy siblings, and 40 patients with other neurologic diseases (OND). Antibodies in serum and cerebrospinal fluid (CSF) to vaccinia and measles viruses were measured, and these were correlated in the multiple sclerosis patients with the clinical characteristics of their disease. The CSF antibody to vaccinia virus was more frequent and at a higher titer in multiple sclerosis patients than in either control group. Moreover, a statistically significant increase was found in both frequency and titer of CSF vaccinia antibody in patients with the progressive form of the disease as compared with those classified as relapsing-remitting. Statistically significant differences between multiple sclerosis patients and their siblings were not observed for CSF or serum measles virus antibody, although both groups had significantly higher serum antibody titers than patients with OND.

Vaccinia virus meningitis in mice after intracerebral inoculation.

The pathogenesis of experimental vaccinia virus infection in weanling mice after intracerebral inoculation was followed with virological, histological, and immunohistological methods. High-dose inoculation, virus spread from brain to thoracic and abdominal viscera probably by an undetected early viremia. Virus did rise to detectable levels in blood by day 5 and was found to be associated with the mononuclear cell fraction. By day 12, 30% of the animals had died and no further deaths occurred. Rise of neutralizing antibody correlated with disappearance of cell-free virus in blood, brain, and viscera. Virus was present in the brains of animals for 20 days after inoculation. This animal model may be useful to study mechanisms of persistent central nervous system virus disease relevant to man.