Cellular and humoral immunity in subacute sclerosing panencephalitis

Immune-dysregulation in subacute sclerosing panencephalitis: An exploratory case-control study

Subacute sclerosing panencephalitis (SSPE) is a chronic progressive neurological condition caused by a defective measles virus. It is postulated that immune-dysregulation might result in persistent infection (immune evasion) as well as initiation of autoimmune phenomenon (via natural killer cells) leading to panencephalitis. The primary objective of this case-control study was to analyse the pattern of immune dysregulation in cases with SSPE. The secondary objective was to assess the correlation between the measured immunological variables and disability/death at 6 months. This was an exploratory case-control study conducted at a tertiary-care referral-facility from January 2020 to September 2021. Thirty consecutive patients fulfilling the Dyken's criteria for SSPE and 30 age-and-sex-matched healthy controls were enrolled. Immunological profile constituted by lymphocyte subset analysis, immunoglobulin levels and complement levels were done in all cases and controls. Cases were staged as per Jabbour's system; disability was assessed using the modified Rankin Scale (mRS). Patients with SSPE had a mean age of 14.76 years (±6.9 years). There were 25 males and 5 females; 6.7% cases belonged to Jabbour's first stage, 40% to second stage and 53.3% to third stage. At least 1/4th had evidence of measles vaccination. Levels of absolute lymphocyte count, B-cells, T cells, helper T-cells, and cytotoxic T-cells were significantly higher in cases. IgG, IgM, and IgE levels were significantly higher while IgD levels were significantly lower in cases. At baseline, 13.3% of cases had a mRS score of 0-2 and 86.7% had a score of 3-6; at 6 months 10% had a mRS score 0-2 (favorable outcome) while 90% had a mRS score 3-6 (poor outcome). Higher IgE levels were found to correlate significantly with favorable outcome. Immune-dysregulation may play a significant role in shaping one's response to measles infection as well as in determining vaccine-efficacy.

Mechanisms of diabetic cardiomyopathy and potential therapeutic strategies: preclinical and clinical evidence

The pathogenesis and clinical features of diabetic cardiomyopathy have been well-studied in the past decade, but effective approaches to prevent and treat this disease are limited. Diabetic cardiomyopathy occurs as a result of the dysregulated glucose and lipid metabolism associated with diabetes mellitus, which leads to increased oxidative stress and the activation of multiple inflammatory pathways that mediate cellular and extracellular injury, pathological cardiac remodelling, and diastolic and systolic dysfunction. Preclinical studies in animal models of diabetes have identified multiple intracellular pathways involved in the pathogenesis of diabetic cardiomyopathy and potential cardioprotective strategies to prevent and treat the disease, including antifibrotic agents, anti-inflammatory agents and antioxidants. Some of these interventions have been tested in clinical trials and have shown favourable initial results. In this Review, we discuss the mechanisms underlying the development of diabetic cardiomyopathy and heart failure in type 1 and type 2 diabetes mellitus, and we summarize the evidence from preclinical and clinical studies that might provide guidance for the development of targeted strategies. We also highlight some of the novel pharmacological therapeutic strategies for the treatment and prevention of diabetic cardiomyopathy.

Evaluation of lymphocyte subgroups in children with subacute sclerosing panencephalitis

The aetiology of subacute sclerosing panencephalitis (SSPE) remains to be fully elucidated, although it follows infection with a hypermutant defective M-protein measles virus. This study analysed peripheral blood lymphocyte subgroups to determine their role in the pathophysiology of SSPE. It included 22 children with SSPE aged 2 - 15 years (patient group) and 22 age- and gender-matched healthy children (control group). In children < 6 years old, there were no statistically significant differences between the two groups in the proportions of lymphocytes expressing the surface markers CD3, CD8, CD19 or CD16/56, or in CD4/CD8 ratio. The proportion of CD4(+) lymphocytes in SSPE patients < 6 years of age was significantly lower compared with the control group. In children >or= 6 years old, there were no significant differences in the lymphocyte subgroups. In conclusion, these findings suggest that a low CD4(+) lymphocyte count might be responsible for SSPE in younger children.

Lymphocyte subsets, TNFα and interleukin-4 levels in treated and untreated subacute sclerosing panencephalitis patients

Immunologic studies in relation to clinical status might help to understand the pathogenesis of subacute sclerosing panencephalitis (SSPE) and the effect of treatment. We measured lymphocyte subsets and intracellular TNFalpha and interleukin-4 levels in peripheral blood in SSPE patients. Patients had elevated percentages of CD8+ cells compared to age-matched control children. Rapidly progressive course was associated with increased CD4+ cells. Treatment with interferons and inosiplex altered the percentage of CD3+, CD4+ and CD19+ cells. TNFalpha and interleukin-4 levels had no correlation with course or treatment. The proportions of lymphocyte subsets appear to have a role in the evolution or manifestations of SSPE, if not in the pathogenesis.

Atypical EEG findings in subacute sclerosing panencephalitis

A total of 72 EEGs from 57 patients with SSPE were studied. The EEG studies in SSPE revealed periodic high amplitude complexes in all except one. Besides periodic complexes, we found several atypical EEG findings including frontal rhythmic delta activity in intervals between periodic complexes, electrodecremental periods following EEG complexes, diffuse sharp waves and sharp-and-slow-wave complexes over frontal regions, and focal abnormalities, such as sharp wave and sharp and slow wave foci, which have been rarely reported previously. We also described a new finding characterized by high amplitude generalized rhythmic sharp wave activity following periodic complexes in one patient.

Effect of treatment on oligoclonal IgG bands and intrathecal IgG synthesis in sequential cerebrospinal fluid and serum from patients with subacute sclerosing panencephalitis

Oligoclonal IgG bands were analyzed in matching pairs of cerebrospinal fluid (CSF) and serum from 12 subacute sclerosing panencephalitis (SSPE) patients, using isoelectric focusing and immunofixation. Each patient was given isoprinosine, and four of the 12 patients were given alpha-interferon in addition. Two to 4 serial CSF and serum samples were collected from each SSPE patient during periods ranging from 1 to 16 months. In 3 SSPE patients a small number of new oligoclonal bands were seen in the follow-up CSF samples. In the other 9 SSPE patients there was no change in CSF band patterns between initial and follow-up specimens. Band patterns in serum remained unchanged between initial and follow-up samples. Although all 12 SSPE cases had higher IgG indices and increased rate of intra blood-brain barrier (BBB) IgG synthesis in comparison to patients with other neurological diseases, the values did not significantly differ between the first and follow-up specimens. We conclude that treatment of SSPE patients with isoprinosine or with isoprinosine and alpha-interferon had no significant effect on the CSF oligoclonal band profiles or IgG synthesis within the central nervous system.

Subacute sclerosing panencephalitis in Riyadh, Saudi Arabia

The clinical features and outcome of disease in 14 cases of subacute sclerosing panencephalitis (SSPE) diagnosed at the King Khalid University Hospital, Riyadh during an 8-year period are similar to those described elsewhere. Therapy was associated with arrest of deterioration for 2.5 years in one patient, and with survival after diagnosis for 2-7 years in four others. Many of the cases had initial misdiagnoses because of the frequently bizarre modes of presentation. It is thought that many more cases of SSPE occur in Saudi Arabia and also in many other tropical countries than are currently recognized. The establishment of national SSPE registries is advocated to improve early identification and management of cases.

Atypical electroencephalographic pattern in a patient with subacute sclerosing panencephalitis

Subacute sclerosing panencephalitis (SSPE) has become rare since the widespread use of the measles vaccine. In this patient with a 5 month history of seizures and progressive dementia due to SSPE, the atypical electroencephalographic pattern was characterized by generalized spike-and-wave discharges, maximal on the right, associated with clinical seizures. After diazepam (intravenously), more typical periodic complexes appeared.

Postmortem detection of measles virus in non-neural tissues in subacute sclerosing panencephalitis

Subacute sclerosing panencephalitis, a rare, progressive, fatal central nervous system disease of children, is caused by measles virus. Clinical signs occur months to several years after recovery from acute measles infection. It is not known where the virus persists while the disease is inapparent. Involvement of organs outside the central nervous system has rarely been documented. To search for possible peripheral reservoirs of measles virus we used in situ hybridization to probe for measles virus RNA and immunocytochemical studies to localize measles virus antigens ina variety of organs taken at autopsy from confirmed cases of subacute sclerosing panencephalitis. Seven of 9 cadavers were found to contain measles virus RNA or antigens, or both, in at least one location outside the central nervous system. These sites included lymphoid organs such as thymus, spleen, lymph nodes, and tonsil, suggesting a role for lymphocytes in disease pathogenesis. Virus was also detected in kidney, lung, and glandular tissues such as pancreas, adrenal, and pituitary. These reservoirs may provide the antigenic stimulus leading to the elevated response characteristic for subacute sclerosing panencephalitis.

Impaired human leukocyte antigen-restricted measles virus-specific cytotoxic T-cell response in subacute sclerosing panencephalitis

The capacity of peripheral blood lymphocytes to proliferate in response to measles virus and to generate measles virus-specific cytotoxic T lymphocytes (CTL) was examined in 4 patients with subacute sclerosing panencephalitis (SSPE). The lymphoproliferative response to measles virus was obtainable in the 4 SSPE patients. In contrast, the CTL response to measles virus was reduced in 3 of the 4 SSPE patients. This defect appeared to be in the generation of the measles virus-specific CTLs, since measles virus-infected target cells from the patients could be lysed by human leukocyte antigen-matched peripheral blood lymphocytes from healthy individuals. The SSPE patients with reduced measles virus CTL response had a normal ability to generate mumps virus, influenza virus, or alloantigen-specific CTLs. The lysis of measles virus-infected targets that was observed with these SSPE patients could be reduced by depleting the effectors of natural killer cells or by performing cold target blocking with K562 cells, indicating that the lysis of the measles virus-infected targets was probably mediated by natural killer cells. These results demonstrate a reduction in the cell-mediated immune response to measles virus as measured by the generation of measles virus-specific CTLs in 3 of the 4 SSPE patients studied. This defect could relate to the persistence of measles virus in these patients.

Lymphocyte subsets at different stages of subacute sclerosing panencephalitis: a study with monoclonal antibodies

Lymphocyte subsets in cerebrospinal fluid (CSF) and peripheral blood were studied using monoclonal antibodies, in patients with subacute sclerosing panencephalitis, eight of whom were at stage 2 and seven at stage 4. Eighteen subjects affected with non immunological diseases constituted the controls. Regardless of the stage, patients with subacute sclerosing panencephalitis had lower percentages of OKT3+ (pan-T) cells in both CSF and peripheral blood, with an increase of OKIa+ cells (B cells, macrophages and active T cells) in peripheral blood. A difference was found in the proportion of OKT4+ (helper-inducer) and OKT8+ (suppressor/cytotoxic) cells in relation to the stage, the most striking finding being a significant decrease of OKT8+ with an increase of T4/T8 ratio in peripheral blood at an early stage.

Relationship between host age and persistence of Theiler's virus in the central nervous system of mice

This study has demonstrated that the ability of BeAn 8386 virus to persist in the central nervous system of mice declines with the increasing age of the host at the time of inoculation. Although persistent infection was established in 1-, 3-, 9-, and 40-week-old mice, there was a significant reduction in both the frequency of virus isolations and the mean virus titers in mice inoculated after 3 weeks of age. The incidence of clinical demyelinating disease (late disease) also decreased in animals infected after 3 weeks of age in parallel with the decline in virus persistence.

Immunological parameters in multiple sclerosis patients with special reference to the herpes virus group

A group of multiple sclerosis (MS) patients (n = 50), most of them in a stable or slightly progressive phase was studied together with a group of neurological control (NC) patients with CNS lesions (n = 38) comparable in age and disability and an age matched group of healthy persons (n = 46). On stimulation of lymphocytes with herpes simplex virus (HSV), cytomegalovirus (CMV) and varicella zoster virus (VZV) a significantly lower interferon production was found in MS patients compared with the NC patients and the healthy controls; when the NC patients were compared with the healthy controls a significantly lower production was also found. The lymphocyte transformation reaction in seropositive MS patients was significantly lower than that seen in the seropositive control groups when HSV was used as antigen. Lower responses, although insignificant, were found when CMV and VZV were used as antigens. There were no differences among the three groups when Con A was used as mitogen in three different concentrations. Likewise spontaneous lymphocyte transformations were equal. The lower interferon production and the lower transformation reactions in MS patients could not be correlated to age, duration of disease, disability, disease activity or impairment. No significant differences in humoral immunity to HSV, CMV and VZV were found in the three groups, a few MS patients were 'true' seronegative to HSV type 1 and 2. Suppressor cell activity induced by Con A and measles virus was comparable in the three groups, although a few MS patients in an active relapsing phase were found to have low suppressor cell activity. Natural killer cell activity against two different cell lines was found equal in the three groups, and there was no difference in the potentiating effect of interferon.

Different virus antibodies in serum and cerebrospinal fluid of patients suffering from subacute sclerosing panencephalitis

Complement fixing (CF) antibody titers to measles, parainfluenza (PI) types 1 and 3, mumps, herpes type 1, and cytomegalovirus (CMV) in serum and cerebrospinal fluid (CSF) of 33 patients with subacute sclerosing panencephalitis (SSPE) were evaluated. Results were analyzed in comparison to 11 patients with neurological diseases other than SSPE and 7 normal subjects. All SSPE patients had elevated serum and CSF measles antibody titers. The number of SSPE patients manifesting elevated titers other than measles did not reach statistical significance when compared to controls, except for PI type 1. This suggests a possible dual infection with measles and PI in SSPE. The anticomplementary effect detected in the serum and CSF of some patients indirectly suggests the presence of immune complexes.