Signaling lymphocyte activating molecule (SLAM) expression in subacute sclerosing panencephalitis

Immune alterations in subacute sclerosing panencephalitis reflect an incompetent response to eliminate the measles virus

In subacute sclerosing panencephalitis (SSPE) the persistence of measles virus (MeV) may be related to the altered immune response. In this study, cytokine responses of lymphocytes and monocytes were evaluated in SSPE compared to controls with non-inflammatory (NICON) and inflammatory (ICON) diseases. Patients with SSPE (n = 120), 78 patients with ICON and 63 patients with NICON were included in this study. Phenotypes of peripheral blood mononuclear cells (PBMC) have been analyzed by flow cytometry. CD3 and CD28, and S. aureus Cowan strain I (SAC) stimulated and unstimulated cells were cultured and IL-2, IL-10, IFN-γ, IL-12p40, IL-12p70 and IL-23 were detected in supernatants by ELISA. MeV peptides were used for MeV-specific stimulation and IFN-γ secretion of PBMC was measured by ELISPOT. Spontaneous and stimulated secretions of IL-10 were lower in SSPE compared to both control groups. T cell stimulation induced lower IFN-γ production than ICON group, but higher IL-2 than NICON group in SSPE. Stimulated PBMC produced lower IL-12p70 in SSPE and had decreased CD46 on the cell surface, suggesting the interaction with the virus. IFN-γ responses against MeV peptides were not prominent and similar to NICON patients. The immune response did not reveal an inflammatory activity to eliminate the virus in SSPE patients. Even IL-10 production was diminished implicating that the response is self-limited in controlling the disease.

Subacute sclerosing panencephalitis and immune thrombocytopenia: More than a coincidence?

Subacute sclerosing panencephalitis (SSPE) is a progressive disease caused by persistent measles virus (MV). It has an incidence of 0.4-2.0/million in Turkey. Immune thrombocytopenia (ITP) is a bleeding disorder whose estimated incidence is 4.2/100.000 person/years in the pediatric age group. We observed three cases with ITP in our cohort of 315 pediatric SSPE cases, an incidence higher than coincidentally expected in the general population. We hypothesize an association between SSPE and ITP. Our three cases had measles 1-2 years before the onset of ITP and 8-10 years before first symptoms of SSPE. A common immunogenetic background creating susceptibility to infection and autoimmunity might play a role. Alternatively, chronic antigenic stimulation by the MV leading to synthesis of cross-reacting antibodies against platelets, or treatment of ITP with immunoglobulins or steroids might affect or alter the development and manifestation of SSPE. The co-occurrence of these two disorders of viral and immune pathogenesis may draw attention to similar observations and provide clues for their mechanisms.

Familial subacute sclerosing panencephalitis associated with short latency

The familial recurrence of subacute sclerosing panencephalitis is rare. The study of such cases and a comparison of intrafamilial with sporadic cases of subacute sclerosing panencephalitis may shed light on important pathogenetic factors. We report on the occurrence of subacute sclerosing panencephalitis in two brothers from rural India, who contracted measles infection simultaneously at ages 3 and 11 years. They developed subacute sclerosing panencephalitis 21 and 37 months later, respectively. A diagnosis of subacute sclerosing panencephalitis was based on history, electroencephalographic changes, and significantly raised levels of cerebrospinal-fluid anti-measles virus immunoglobulin G. A comparison of intrafamilial with sporadic cases of subacute sclerosing panencephalitis revealed that latency in familial subacute sclerosing panencephalitis involved a median of 6.4 years (range, 1.0-10.9), significantly (P < 0.05) shorter than in sporadic cases with a median of 9.7 years (range, 2.7-23.4). This difference was because of significantly later infection with measles virus and an earlier onset of encephalitis. We describe the first siblings affected by subacute sclerosing panencephalitis from the Indian subcontinent. We confirmed a more rapid manifestation of subacute sclerosing panencephalitis after measles virus infection in intrafamilial compared with sporadic subacute sclerosing panencephalitis.