Serum amyloid A (SAA) in viral infection: rubella, measles and subacute sclerosing panencephalitis (SSPE).

Serum amyloid A (SAA) levels were determined in the serial serum samples of eight rubella, 10 measles and seven subacute sclerosing panencephalitis (SSPE) patients. An early rise in SAA levels was detected in the acute phase in rubella and measles, followed by a prompt decrease in the convalescent phase. In a number of measles and rubella patients from whom early serum samples were available, the rise of SAA levels could be demonstrated before specific viral antibodies could be detected by complement fixation (CF) (measles) and haemagglutination inhibition (HI) (rubella). In only one rubella and one measles patient was no rise of SAA level detected. In SSPE only a moderate increase in SAA levels was noted except in one patient during a temporary deterioration, at which time the SAA level was very high; it returned to close to normal shortly thereafter. The possibility that SAA levels might be of value in monitoring the severity of infections, the recovery process and effects of anti-viral agents is discussed.     

Immunological study of the agent responsible for subacute sclerosing panencephalitis and biochemical characterization of measles antibody in subacute sclerosing panencephalitis

Antibody of restricted heterogeneity produced in high titers in response to a given antigen is commonly observed in patients affected with subacute sclerosing panencephalitis and is comparable to what is observed in rabbits hyperimmunized with bacterial vaccines. Subacute sclerosing panencephalitis immunoglobulins were isolated and partially sequenced. Their immunological activity was measured with measles virus, subacute sclerosing panencephalitis virus (LEC strain) and distemper virus.     

Biological and biochemical characterization of a latent subacute sclerosing panencephalitis (SSPE) virus infection in tissue culture

The present investigation describes the biological and biochemical properties of a persistent SSPE virus infection. Persistently infected cells were derived by cocultivation of infected brain cells and uninfected Vero cells, and cultures were maintained by normal subculturing methods. No infectious virus was ever released from these cultures, and all attempts to induce infectious virus release were unsuccessful. Biological assays showed that infected cells contained nucleocapsid and salt-dependent hemagglutinin antigens, whereas the normal hemagglutinin appeared not to be present. Electron microscopic examination demonstrated the presence of both intranuclear and cytoplasmic nucleocapsids together with the release of virus particles (defective?) from the cell membrane. Biochemical analysis demonstrated that approximately 90% of the intracellular genomic RNA was defective or subgenomic although a small quantity of infectious genomes was present. It is proposed that the large quantities of defective genomes in the infected cells are the major factor in the maintenance of this persistent infection.     

Subacute sclerosing panencephalitis (SSPE) agent in hamsters. 3. Induction of defective measles infection in hamster brain

A hamster-adapted SSPE agent was shown to cause a productive infection in weanling hamster brain which changed to a cell-associated or defective infection coincident with the appearance of measles antibodies in serum. Antibodies to measles hemagglutinin, hemolysin and nucleocapsid antigens developed in serum which also contained neutralizing activity for regular measles virus. The agent recovered from brains prior to the appearance of serum antibodies was infectious in cell free media, capable of rapidly destroying Vero cell cultures and able to progressively destroy primary hamster brain cultures. In contrast, the agent recovered from brain after serum antibodies were present was infectious only within cells, destroyed Vero cells ineffectively and spread slowly through primary brain tissue cultures releasing minute amounts of extracellular virus intermittently even though no measles antibodies were present in the culture media. Nevertheless, infected giant cells in the primary brain cultures contained both the HA and HL measles antigens in their cytoplasmic membranes. This in vivo conversion of a productive to a cell-associated cerebral infection appeared to be caused by the host antibody response and may mirror the initial events of human SSPE and possibly other slow or latent measles infections of the CNS.     

Intranuclear polypeptides of measles and subacute sclerosing panencephalitis virus-infected cultures

CV-1 cells infected with either measles virus or five different isolates of SSPE virus each manifest a unique overall pattern of intranuclear polypeptides as well as differences in growth and yields of infectious particles. Of the viral structural proteins within the nucleus, both the P and M species most commonly exhibit migration differences on polyacrylamide gels. Each virus also generates a nonstructural protein of 20,000 daltons. Two of the SSPE viruses grow more slowly than the other viruses and produce significantly lower yields of infectious particles. Their nuclear isolates contain the most slowly migrating M protein, as well as two large species of 80,000 and 135,000 daltons. These findings suggest that there are differences in nuclear polypeptides between the viruses, not reflected in virion structural protein composition nor in the infected host cell cytoplasm, and that these changes occur particularly in less productive, more indolent infections.     

High risk of subacute sclerosing panencephalitis following measles outbreaks in Georgia

ObjectiveTo describe cases and estimate subacute sclerosing panencephalitis (SSPE) risk following large-sale measles outbreaks in Georgia. A rare, fatal late complication of measles, SSPE is often overlooked in assessments focused on the acute illness. Georgia had 8377 and 11,495 reported measles cases during the 2004–2005 and 2013–2015 outbreaks, respectively, but SSPE burden has not been assessed.MethodsSSPE cases diagnosed during 2008–2017 were identified from hospitalization registries in major neurological departments likely to admit SSPE patients. Information on reported measles cases and deaths was obtained from the national measles surveillance system and published reports. The risk of SSPE (number of measles cases per one SSPE case) was calculated for cases associated with the 2004–2005 outbreak. Crude estimates were adjusted to account for potential under-reporting of measles, using 50%, 25% and 10% estimates of completeness of reporting.ResultsSixteen SSPE cases diagnosed during 2008–2017 were identified. Eleven (92%) of 12 SSPE cases with a known history of measles had infection at ≤2 years and one (8%) at 3 years of age. Crude estimate of SSPE risk for the 2004–2005 outbreak was 1:1396. Adjusted estimates were 1:2792, 1:1:5584 and 1:13 960, assuming 50%, 25% and 10% completeness of reporting measles cases, respectively.ConclusionsThe review demonstrated substantial risk of SSPE in Georgia, supporting recent data suggesting that risk of SSPE following measles infection is higher than previously thought. To prevent SSPE in Georgia, very high timely immunization coverage for measles should be achieved among children, and immunity gap among adults should be closed.     

The relationship between measles virus-specific antibodies and oligoclonal IgG in the cerebrospinal fluid (CSF) in patients with subacute sclerosing panencephalitis (SSPE) and multiple sclerosis (MS)

A comparison of measles virus antibody titers in sera and CSF samples has demonstrated that antibodies appearing in the latter type of samples are locally produced in the central nervous system in all patients with SSPE and in about 60% of patients with MS. The relationship between these locally produced measles virus antibodies and the oligoclonal IgG in patients with these diseases was studied by use of two different techniques. One technique was to absorb concentrated CSF with purified measles virus particles to analyse their capacity to remove oligoclonal IgG. Antigen-antibody complexes formed were isolated by sedimentation whereafter IgG was eluted at pH levels of 4.0, 3.0 and 2.0. The second technique was to make a preparatory electrophoresis of concentrated CSF and then to analyse the distribution of antibodies against different measles virus antigens in fractions collected. In the case of SSPE repeated absorbtions with measles virus antigens caused an almost complete removal of all oligoclonal IgG. After preparatory electrophoresis peaks of antibody activities correlated in their electrophoretic position to the occurrence of bands of oligoclonal IgG. Different bands were interpreted to carry different antibody activities. Results of studies of materials from MS patients differed somewhat from those obtained in characterization of materials from SSPE patients. Only in exceptional cases could absorption with purified virus particles modify the band pattern of oligoclonal IgG and generally absorption with measles virus antigens in the selected cases did not influence the level of IgG in the samples. However in low pH eluates measles virus antibody activities and a few bands of oligoclonal IgG were recovered. Preparatory electrophoresis of concentrated CSF material from MS patients resulted in a varying distribution of antibodies against different measles virus antigens but a distinct correlation between accumulation of antibody activity and bands present in the electropherogram could not be discernedIt is concluded that in the case of SSPE the oligoclonal IgG represents an oligoclonal IgG response to an intense hyper-immunization with measles virus antigens. In contrast a local immunization with measles virus antigens accounted only for a few bands of oligoclonal IgG in cases of MS whereas the potential antibody activity of the major part of oligoclonal IgG remains to be explained.Supported by grants from the Swedish Medical Research Council (Project No. 16X-116).Presented at the workshop on molecular and pathogenetic aspects of measles virus, 9./11. April 1974, Belfast, Northern Ireland.     

Detection of measles virus antigen(s) in peripheral lymphocytes from patients with subacute sclerosing panencephalitis

Summary Peripheral blood lymphocytes from 5 patients with subacute sclerosing panencephalitis (SSPE) were stimulated with phytohemagglutinin (PHA) and analyzed for the presence of the measles virus antigen(s) by immunofluorescence (IF). For detection of viral antigen fluorescein-conjugated globulins from SSPE patients or from measles convalescents both with high anti-measles titer were used. Peripheral blood lymphocytes from 5 children with measles were used as a positive control.Measles virus antigen(s) were localized in PHA-transformed lymphocytes in all SSPE patients.The present results indicate that in SSPE measles-like virus infection may be found not only in the central nervous system, but also in the circulating lymphoid cells.With 2 Figures     

Immunological studies of subacute measles encephalitis in ferrets: similarities to human subacute sclerosing panencephalitis.

Ferrets inoculated with subacute sclerosing panencephalitis virus strains D.R. and Biken developed a subacute encephalitis. Brain extracts, at neutral pH, from these ferrets showed high measles antibody titers, increased concentrations of immunoglobulin G (IgG), and higher IgG/albumin ratios than those of controls. Although the brain extracts of subacute encephalitic animals showed significant synthesis of measles-specific IgG (20 to 60% of the total IgG) within the central nervous system, the electrophoretic patterns of these extracts did not show oligoclonal bands in the gamma-globulin region. Brain residues from most ferrets with subacute encephalitis, when eluted at low pH, demonstrated the presence of bound measles-specific antibodies. Excluding the electrophoresis data, other results are identical to those seen in human subacute sclerosing panencephalitis, indicating that the subacute encephalitis in ferrets may serve as a model for human subacute sclerosing panencephalitis.     

Detection and characterization of measles virus strains in cases of subacute sclerosing panencephalitis in Croatia

Two cases of subacute sclerosing panencephalitis (SSPE), diagnosed in Croatia in 2002, were investigated. The coding regions of the matrix (M), hemagglutinin (H) and nucleoprotein (N) genes of measles virus were sequenced following direct RT-PCR amplification of viral RNA extracted from brain tissue. Phylogenetic analysis of the sequences of H and N genes, showed that both strains belonged to genotype D6. No vaccine strain was detected although both patients had been previously immunized. The comparison of analyzed sequences of two SSPE causative viruses with corresponding sequences of D6 genotype and with each other revealed a number of mutations in N and H gene sequences. In comparison to the Edmonston reference strain, the M gene of the SSPE viruses showed the characteristic biased hypermutation and a premature termination codon in one of the patients.     

Lymphokines and immunoregulatory molecules in subacute sclerosing panencephalitis

Frozen brain specimens from six patients with subacute sclerosing panencephalitis (SSPE) were analyzed immunohistochemically for the presence of leukocyte subpopulations and specific cytokines. In brain regions demonstrating perivascular cell infiltration and gliosis, CD4 and CD8 positive cells were identified within the brain parenchyma. Cytokine analysis revealed cells staining positively for tumor necrosis factor-alpha and interferon-gamma. These results were similar to those observed in multiple sclerosis (MS) and progressive rubella panencephalitis tissue and were different from other predominantly noninflammatory neurologic diseases and normal controls. Although SSPE and MS differ significantly in their etiology and histopathology, the similarities in leukocyte and cytokine staining patterns suggest a common mechanism of disease progression.     

Western blot analyses of measles virus antibody in normal persons and in patients with multiple sclerosis, subacute sclerosing panencephalitis, or atypical measles.

A version of the Western blot was developed to detect serum antibodies against measles virus polypeptides. With this technique, a seroepidemiological survey of antibodies to the several measles virus proteins in diverse measles-related conditions was conducted. The sera were obtained from individuals with a recent or long-past history of natural measles, from persons with a history of immunization with live attenuated measles vaccine, and from patients with multiple sclerosis, subacute sclerosing panencephalitis, or atypical measles. The findings indicated that live attenuated measles vaccine elicits an antibody response qualitatively resembling that of a natural infection. In addition, multiple sclerosis patients made less antibody to the measles virus M protein than did individuals with a long-past history of natural measles. Thus, the immunological reaction of multiple sclerosis patients to measles virus is qualitatively, as well as quantitatively, different from that of normal persons. Finally, persons with subacute sclerosing panencephalitis and atypical measles mounted abnormally high antibody responses to measles virus polypeptides, in particular the P protein.     

HLA and C4 in subacute sclerosing panencephalitis

The frequencies of HLA-A, B, C, DR and DQ antigens were studied in 63 Japanese patients with subacute sclerosing panencephalitis (SSPE). The results could not confirm the statistical association between SSPE and HLA antigens. In addition, the allele frequencies of complement components C4, C2 and BF were determined in the 20 haplotypes with 10 unrelated SSPE patients. A significant association of C4A QO with SSPE in Caucasians was not found in Japanese.     

Molecular characterization of measles virus strains causing subacute sclerosing panencephalitis in France in 1977 and 2007

Measles virus strains from two subacute sclerosing panencephalitis (SSPE) cases diagnosed in 1977 (Laine strain) and in 2007 (Hoedts strain) were studied. Phylogenetic analysis based on C-terminal part of the nucleoprotein and the entire H gene showed that Hoedts strain, circulating in France presumably in the 1980s, belonged to genotype C2. However, Laine strain, suspected to have circulated between 1940s and 1960s, could not be assigned to any known measles virus genotypes. Sequences analysis of the Laine strain suggested that it originated from a measles virus that may have circulating at the same period as the Edmonston strain. The analysis of the whole genome of both SSPE strains revealed biased hypermutations in M, F, and H gene. Some of these mutations like the L165P found in the M protein sequence of the Laine strain, the amino acid position 94, where a mutation M94V was found in the F protein sequence of the Hoedts strain are known to play an important role in the glycoprotein interaction and to impair the ability of measles virus strain to produce cell-free infectious viral particles.This is the first study on molecular characterization of the entire coding region of measles virus isolated from SSPE cases in France.     

Isolation and characterisation of a defective measles virus from a subacute sclerosing panencephalitis patient.

A cytopathic measles virus was isolated from a brain biopsy of a subacute sclerosing panencephalitis (SSPE) patient. The agent could be transferred to Vero cells by cocultivation, but the infectivity always remained cell-associated -ie, a defective virus infection. The cell-associated nature of the virus was retained through 25 passages in Vero cells. Intracerebral inoculation of hamsters (2-6 days old) with the cocultured Vero cells gave rise to 100% mortality in 5-7 days. The virus retained its cell-associated nature after passage in hamsters. Electron microscopy of the brain and Vero cocultures showed the presence of virus-like ribonucleoparticles mainly in the nucleus. The presence of viral antigens in the nucleus, cytoplasm, and on the plasma membranes was confirmed by immunofluorescence. Using a combination of immunological and biochemical techniques, it was shown that all the viral proteins were synthesized with the exception of the haemagglutinin. Inclusion of the fusion inhibitor SV4814 (CBZ-D phenylalanine-L-phenylalanine-L-arginine-NO2) in the culture medium led to the elimination of the SSPE infection.