Progressive multifocal leukoencephalopathy (PML) is a severe demyelinating disease of the central nervous system (CNS) caused by reactivation of the polyomavirus JC (JCV) typically in immunocompromised individuals. The risk of PML among rheumatic diseases may be higher for systemic lupus erythematosus (SLE), without, however, a clear association with the type and intensity of background therapy. We present the development and outcome of PML in a 32-year-old female lupus patient under mild immunosuppressive treatment, yet with marked B-cell lymphopenia in the peripheral blood and bone marrow (<1% of total lymphocytes). Despite treatment with the immune checkpoint inhibitor pembrolizumab, the patient showed progressive neurological and brain imaging deterioration and eventually died 15 months after PML diagnosis. To unveil possible underlying genetic liabilities, whole exome sequencing was performed which identified deleterious variants in GATA2 and CDH7 genes, which both have been linked to defective T- and/or B-lymphocyte production. These findings reiterate the possible role of disease-/patient-intrinsic factors, rather than that of drug-induced immunosuppression, in driving immune dysregulation and susceptibility to PML in certain patients with SLE.
Blood Oxygen Level Dependent (BOLD) is a commonly-used MR imaging technique in studying brain function. The BOLD signal can be strongly affected by specific sequence parameters, especially in small field strengths. Previous small-scale studies have investigated the effect of TE on BOLD contrast. This study evaluates the dependence of fMRI results on echo time (TE) during concurrent activation of the visual and motor cortex at 1.5 T in a larger sample of 21 healthy volunteers. The experiment was repeated using two different TE values (50 and 70 ms) in counterbalanced order. Furthermore, T2* measurements of the gray matter were performed. Results indicated that both peak beta value and number of voxels were significantly higher using TE = 70 than TE = 50 ms in primary motor, primary somatosensory and supplementary motor cortices (p < 0.007). In addition, the amplitude of activation in visual cortices and the dorsal premotor area was also higher using TE = 70 ms (p < 0.001). Gray matter T2* of the corresponding areas did not vary significantly. In conclusion, the optimal TE value (among the two studied) for visual and motor activity is 70 ms affecting both the amplitude and extent of regional hemodynamic activation.
About Me
School of Medicine, University of Crete, Heraklion, Greece
School of Medicine, University of Crete, Heraklion, Greece