Outcome Of Progressive Multifocal Leukoencephalopathy Research Articles

Progressive multifocal leukoencephalopathy and spectrum of predisposing conditions: a 20-year retrospective cohort study in a tertiary center in São Paulo, Brazil.

Epidemiological studies on predisposing conditions and outcomes of progressive multifocal leukoencephalopathy (PML) cases have been carried out exclusively in high-income countries. We aim to report and compare the main characteristics and outcomes of patients with PML and several underlying diseases in a referral center in a middle-income country. We performed a retrospective cohort study of PML cases admitted to a tertiary care hospital in São Paulo, Brazil during 2000-2022. Demographic and PML-specific variables were recorded. One-year case-fatality rate and factors associated with death were identified using a multivariate Cox proportional hazards regression model. Ninety-nine patients with PML were included. HIV infection (84.8%) and malignancy (14.1%) were the most prevalent underlying conditions. Other predisposing diseases were autoimmune/inflammatory diseases (5.1%) and solid organ transplantation (1.0%). One (1.0%) patient had liver cirrhosis and another (1.0%) patient was previously healthy. Focal motor deficits (64.2%) and gait instability (55.1%) were the most common signs. The one-year case-fatality rate was 52.5% (95% CI 42.2-62.7). The one-year case-fatality rate (95% CI) in patients with or without malignancy (85.7%, 95% CI 57.2-98.2% and 47.1%, 95% CI 36.1-58.2%, respectively) were statistically different (P = 0.009). Crude and adjusted Cox regression models identified malignancy as independently associated with death (adjusted HR = 3.92, 95% CI 1.76-8.73, P = 0.001). HIV/AIDS was the predisposing condition in 84.8% of PML cases. The one-year case-fatality rate was 52.5% and having a malignancy was independently associated with death. This study reports emerging data on the epidemiology and outcome of PML in a middle-income country.

Progressive Multifocal Leukoencephalopathy in Systemic Lupus Erythematosus: A Consequence of Patient-Intrinsic or -Extrinsic Factors?

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.

No Association Between HLA-B*57:01 and Prevalence and/or Outcome of Progressive Multifocal Leukoencephalopathy in a French Nationwide Human Immunodeficiency Virus Cohort.

Among 34,351 patients living with human immunodeficiency virus with available HLA-B*57:01 included in the Dat'AIDS cohort, 194 patients (0.56%) had a history of progressive multifocal leukoencephalopathy (PML) and 1,746 (5.08%) were carriers of HLA-B*57:01. The frequency of HLA-B*57:01 was similar among patients with history of PML compared with patients without a history of PML (6.19% [95% confidence interval, CI 2.8%-9.6%] vs. 5.08% [95% CI 4.8%-5.3%]; p = .48). Among patients with PML, clinical and biological characteristics at PML diagnosis and the PML outcome were not different according to HLA-B*57:01 status.

Clinical and laboratory features and prognostic factors for outcome of progressive multifocal leukoencephalopathy in HIV-infected patients

Objective: To analyze clinical and laboratory features to predict the outcome of progressive multifocal leukoencephalopathy (PML) in HIV-infected patients.Materials and methods: Retrospective analysis of medical histories of HIV-infected patients with CNS lesions in 2015–2017, and dynamic monitoring of HIV patients with CNS lesions in 2018–2019, who were intensive care unit (ICU) in Infectious Clinical Hospital No. 2 of the Department of Health of Moscow.Results and discussion: A total 196 patients with encephalitis/meningoencephalitis: 124 (63%) patients with detected JCPyV in the cerebrospinal fluid (CSF) — study group (JCPyV+), 72 patients with undetectable JCPyV in CSF — comparison group (JCPyV–). Late terms of hospitalization were noted, mainly in the JCPyV+ group (mean — 58±6 days). The majority of patients had severe immunodeficiency, in the JCPyV+ group the number of patients with CD4&lt;200 cells/μl was significantly higher than in the JCPyV– group (87.8% and 75.8%, p&lt;0.05). Only 22% of patients received antiretroviral therapy (ART) prior to hospitalization. The main clinical manifestations of PML in the study were: paralysis and paresis of the limbs, speech impairment, cognitive disorders in combination with cerebral symptoms in the absence of meningeal signs. In 87.8% patients with positive JCPyV DNA no other pathogens were detected in the CSF; in the patients without PML the detection of infectious agents in the CSF was also rare (14.3%). The disease led to the death for 78% patients in the JCPyV+ group and 72% JCPyV– group, p&gt;0.05. The chance of survival was 2.5 times higher for patients admitted to hospital less than 14 days after deterioration (OR=2.468 [95% CI: 1.244–4.898]). Patients with CD4&lt;200 cells/μL were 5.5 times more chance to die than patients with higher CD4 rates (OR=5.449 [95% CI: 2.388–12.431]). There was no relationship between the concentration of JCPyV DNA and HIV RNA in the CSF and their impact for the disease outcome.Conclusion: Survival prognosis for PML during treatment in ICU was worser for patients hospitalized after 14 days from the onset of symptoms and with CD4&lt;200 cells/μL. Early ART initiation for all HIV-positive individuals significantly reduces the number of opportunistic infections and improve life expectancy.

Outcome of Progressive Multifocal Leukoencephalopathy Treated by Interleukin-7.

Restoring anti-JC virus (JCV) immunity is the only treatment of progressive multifocal leukoencephalopathy (PML). Interleukin-7 is a cytokine that increases number and function of T cells. We analyzed a population of PML patients who received recombinant human IL-7 (rhIL-7) to estimate survival and its determinants. After exclusion of patients with missing data or receiving other immunotherapies, findings from 64 patients with proven PML who received rhIL-7 between 2007 and 2020 were retrospectively analyzed. Logistic regression was used to analyze variables associated with one-year survival. Underlying conditions were HIV/AIDS (n=27, 42%), hematological malignancies (n=16, 25%), primary immunodeficiencies (n=13, 20%), solid organ transplantation (n=4, 6%) and chronic inflammatory diseases (n=4, 6%). One-year survival was 54.7% and did not differ by underlying condition. Survival was not associated with baseline characteristics, but with a >50% increase in blood lymphocytes (OR 4.1, 95%CI 1.2-14.9) and CD4+ T cells (OR 5.9, 95%CI 1.7-23.3), and a > 1 log copies/mL decrease in cerebrospinal fluid JCV DNA (OR 7.6, 95%CI 1.6-56.1) during the first month after rhIL-7 initiation. Side effects were mainly local and flu-like symptoms (n=8, 12.5%) and PML-immune reconstitution inflammatory syndrome (IRIS) (n=5, 8%). In this non-controlled retrospective study, survival did not differ from that expected in HIV/AIDS patients, but might have been improved in those with hematological malignancies, primary immunodeficiencies and transplant recipients. RhIL-7 might have contributed to the increase in blood lymphocytes and decrease in CSF JCV replication that were associated with better survival. ANN NEUROL 2022;91:496-505.

Clinical Presentation and Disease Course of 37 Consecutive Cases of Progressive Multifocal Leukoencephalopathy (PML) at a German Tertiary-Care Hospital: A Retrospective Observational Study.

Background: Progressive multifocal leukoencephalopathy (PML) caused by JCV is a rare but frequently fatal disease of the central nervous system, usually affecting immunocompromised individuals. Our study aims to expand the data on patient characteristics, diagnosis, clinical course, possible PML-directed treatment, and outcome of patients with PML at a German tertiary-care hospital.Methods:In this single-center observational cohort study, 37 consecutive patients with a confirmed diagnosis of PML seen at the University Medical Center Hamburg-Eppendorf from 2013 until 2019 were retrospectively analyzed by chart review with a special focus on demographics, risk factors, and clinical aspects as well as PML-directed treatment and survival.Results:We identified 37 patients with definite, probable, and possible PML diagnosis. 36 patients (97%) had underlying immunosuppressive disorders such as HIV/AIDS (n = 17; 46%), previous treatment with monoclonal antibodies (n = 6; 16%), hematological or oncological malignancies (n = 6; 16%), sarcoidosis (n = 5; 14%), solid organ transplantation (n = 1; 3%), and diagnosis of mixed connective tissue disease (n = 1; 3%). In only one patient no evident immunocompromised condition was detected (n = 1; 3%). Treatment attempts to improve the outcome of PML were reported in 13 patients (n = 13; 35%). Twenty seven percent of patients were lost to follow-up (n = 10). Twenty four-month survival rate after diagnosis of PML was 56% (n = 15).Conclusion: This interdisciplinary retrospective study describes epidemiology, risk factors, clinical course, and treatment trials in patients with PML at a German tertiary-care hospital. Acquired immunosuppression due to HIV-1 constituted the leading cause of PML in this monocenter cohort.

Inadequate Immune Humoral Response against JC Virus in Progressive Multifocal Leukoencephalopathy Non-Survivors.

JC virus (JCV) causes progressive multifocal leukoencephalopathy (PML) in immunosuppressed patients. There is currently no effective specific antiviral treatment and PML management relies on immune restoration. Prognosis markers are crucially needed in this disease because of its high mortality rate. In this work, we investigated the compartmentalization of JCV strains as well as the humoral neutralizing response in various matrices to further understand the pathophysiology of PML and define markers of survival. Four patients were included, of which three died in the few months following PML onset. Cerebrospinal fluid (CSF) viral loads were the highest, with plasma samples having lower viral loads and urine samples being mostly negative. Whether at PML onset or during follow-up, neutralizing antibody (NAb) titers directed against the same autologous strain (genotype or mutant) were the highest in plasma, with CSF titers being on average 430-fold lower and urine titers 500-fold lower at the same timepoint. Plasma NAb titers against autologous genotype or mutant were lower in non-survivor patients, though no neutralization “blind spot” was observed. The surviving patient was followed up until nine months after PML onset and presented, at that time, an increase in neutralizing titers, from 38-fold against the autologous genotype to around 200-fold against PML mutants. Our results suggest that patients’ humoral neutralizing response against their autologous strain may play a role in PML outcome, with survivors developing high NAb titers in both plasma and CSF.

Brief Report: Decreased JC Virus-Specific Antibody-Dependent Cellular Cytotoxicity in HIV-Seropositive PML Survivors.

Progressive multifocal leukoencephalopathy (PML) is an often fatal disease caused by JC virus (JCV) in severely immunocompromised patients, including HIV patients. Development of therapeutics to prevent or treat PML is an urgent medical need. While JCV-specific T cells are crucial to control JCV and recover from PML, the role played by antibodies remains unclear. Anti-JCV antibodies, including potent neutralizing antibodies, can be detected in most infected adults, yet in PML patients, JCV seems to escape from neutralization. Whether antibodies can contribute to JCV control by eliciting Fc-mediated effector functions activity has not been evaluated. We measured the capacity of plasma anti-JCV VP1 antibodies to recruit Fc receptor (FcR)-bearing effector cell functions in 28 HIV patients, comparing subjects without PML with PML survivors (PML S) who were alive 1 year after disease onset or PML progressors (PML P) who succumbed within the first year. Antibody titers against JCV VP1 and HIV gp140 trimer were determined by end-point titer dilution ELISA. FcR-mediated natural killer cell degranulation and IFN-γ production were measured as surrogate for in vitro antibody-dependent cellular cytotoxicity (ADCC). PML S had higher JCV antibody titers than PML P and patients without PML. However, anti-JCV antibodies had a higher ability to functionally engage FcR in PML P than PML S. Antibody titers and ADCC activity did not vary over time in PML S. Anti-HIV antibody titers and ADCC activity were similar among groups. The ability of anti-JCV antibodies to stimulate FcR-bearing effector cell activity might contribute to the outcome of PML. Further studies are warranted to define Fc-mediated functions of anti-JCV antibodies and evaluate whether ADCC can contain JCV replication.

Treatment of natalizumab-associated PML with filgrastim.

ObjectiveThere is no consensus on the treatment of progressive multifocal leukoencephalopathy (PML) occurring in multiple sclerosis (MS) patients treated with natalizumab (Nz). We report novel immune activating treatment with filgrastim of Nz‐associated PML in MS patients treated at Rush University Medical Center.MethodsWe retrospectively analyzed 17 Nz‐PML patients treated at this single tertiary referral center between 2010 and 2017. We reviewed the clinical symptoms, diagnostic methods, survival, outcome and MS modifying therapy (MSMT) after Nz‐PML.Results PML occurred after an average of 49 Nz infusions. To facilitate JCV elimination by accelerating immune reconstitution inflammatory syndrome (IRIS), all patients received subcutaneous filgrastim upon PML diagnosis and discontinuation of Nz; eight received plasma exchange (PLEX). Earlier than previously published, PML‐IRIS occurred in 15 of 17 (88.2%) patients within a mean of 57.4 days (SD 21.20) after the last Nz infusion. Seven patients recovered to or near baseline. There were no PML/IRIS–related fatalities but one patient committed suicide 2.5 years later. PLEX had no impact on PML outcome. Of 17 patients, 3 (18%) had MS relapses within 1 year after PML, and 5 (29%) beyond 1 year of PML onset, which is lower than expected in highly active MS patients. Eight patients started MSMTs after Nz‐PML on an average of 26 months after Nz withdrawal.InterpretationOur findings indicate that immunoactivation with filgrastim during PML and careful management of subsequent IRIS is likely beneficial in patients with Nz‐PML, without worsening MS. The clinical course of MS may be ameliorated by PML.

Characterization of progressive multifocal leukoencephalopathy (PML) in patients treated with rituximab, brentuximab and ibrutinib: A report from the Southern Oncology Network on Adverse Reactions (SONAR).

133 Background: Since the advent of Rituximab (R) in 1997, cancer immunotherapy is increasingly used for management of lymphoproliferative disorders. Unexpected cases of PML have been reported in HIV-negative patients in 2005 receiving Rituximab ( R) and subsequently in 2012 and 2014, who received brentuximab vedotin ( B) or ibrutinib ( I), respectively. We sought to compare and contrast clinical characteristics and outcomes of PML in HIV-negative patients who were treated with R, B or I therapy. Methods: Retrospective analysis of the FDA adverse event reporting system (FAERS) and previously published data by our group with confirmed cases of PML associated with R (1997-2008), B and I therapy (2009-2015). Results: PML develops early during the therapy with B and I, compared to that of R group. Confirmation of the diagnosis of PML by MRI in conjunction with JC virus identification in the cerebrospinal fluid or brain biopsy using objective criteria was found only in 40-60% of the cases. Among confirmed cases of R, I, or B-associated PML, mortality was &gt; 90%, usually occurring within weeks to months following diagnostic confirmation. Rare cases of survival were associated with return of immunologic function, including in one case development of an immune reconstitution syndrome. Conclusions: This is the first study that compared the clinical characteristics of PML in R, B and I. PML cases can occur early during the therapy using B and I, while usually occurs late with R. Additional research is needed to quantify the risk factors of PML and to know if this association is causal or incidental. Meanwhile, physicians and patients should be vigilant in detecting and reporting this rare AE to minimize future fatalities [Table: see text]

Treatment of Progressive Multifocal Leukoencephalopathy With Mirtazapine.

Progressive multifocal leukoencephalopathy (PML) is a rare, JC-virus-mediated, demyelinating disease with a high mortality rate. As no recommended treatment exists, mirtazapine, a potential blocker of virus entry into cells, has been empirically used. We analysed existing data on mirtazapine's efficacy to treat PML by systematically reviewing the literature since 2005, when it was first used. Searches in PubMed, EBSCO, SCOPUS and Google Scholar between January 2005 and December 2015, identified five cohort studies and 74 case reports.No statistically significant effect of mirtazapine on PML outcome was observed in the cohort studies. From studying thecase reports, mortality rate for PML was associated with the underlying circumstances, such as an older age, the use of an immunosuppressant, orPML occurring in patients with a haematological malignancy or a transplant. Except for natalizumab-associated PML, we did not highlight any potential benefit of mirtazapine on disease outcomes. Further interventional studies are needed to confirm that 5-HT2AR inhibition is relevant to treat PML.

Low frequencies of central memory CD4 T cells in progressive multifocal leukoencephalopathy.

Objectives:To assess alterations in the composition of peripheral immune cells in acute progressive multifocal leukoencephalopathy (PML).Methods:Fresh blood samples from 5 patients with acute PML and 10 healthy controls were analyzed by flow cytometry for naive, central memory and effector memory CD4 and CD8 T cells, B lymphocytes, plasma cells, memory B cells, plasma blasts, and natural killer (NK) cells. The frequency of central memory CD4 T cells was determined longitudinally during the course of PML in 2 patients.Results:The frequencies of naive, central memory and effector memory CD8 T cells, B cells, plasma cells, and NK cells were not altered in patients with PML. In contrast, the frequencies of naive CD4 T cells (p = 0.04) and central memory CD4 T cells (p < 0.00001) were reduced and the frequencies of effector memory CD4 T cells were increased (p = 0.01). Longitudinal analysis showed that this pattern was preserved in a patient with fatal PML outcome and restored in one patient who recovered from PML.Conclusions:These data indicate that PML is associated with reduced frequencies of peripheral central memory helper T cells but not with alterations in the frequencies of cytotoxic T cell populations, B lymphocytes, plasma cells, or NK cells.

Application of serum natalizumab levels during plasma exchange in MS patients with progressive multifocal leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML) is a severe complication of natalizumab treatment. Restoring immune function by plasmapheresis/immunoadsorption (PLEX/IA) is important for the outcome of PML. We report on four multiple sclerosis (MS) patients whom developed PML during natalizumab treatment, in whom we measured serum natalizumab concentrations before and during PLEX. Depending on the serum natalizumab concentration at the time of PML diagnosis, the number of PLEX treatments necessary to reach subtherapeutic serum natalizumab concentrations is variable. Measuring serum natalizumab concentrations before and during PLEX is helpful to determine the optimum number of PLEX treatments in individual MS patients with PML.

Progressive multifocal leukoencephalopathy in patients with sarcoidosis

To describe characteristics, risk factors, and treatment outcome of progressive multifocal leukoencephalopathy (PML) complicating sarcoidosis. A retrospective chart and literature review was performed. Patients were identified through records from physicians of the Groupe Sarcoïdose Francophone. Each case was compared with 3 controls. Ten cases were found (8 men). The median age at sarcoidosis diagnosis was 34.9 (±6) years. PML and sarcoidosis were diagnosed concomitantly in 2 cases, while sarcoidosis was previously known in 8 cases, including 7 cases treated with steroids (mean time between sarcoidosis diagnosis and PML was 114 [±99] months). The mean CD4 cell count was 215 (±139)/mm(3). Neurosarcoidosis was thought to be the problem in 8 cases and treatment was intensified, delaying PML diagnosis by 4.5 (±3.9) months. Eight patients received PML-specific treatment. On the whole, 6 patients died of PML within a mean time of 8 (±4.3) months. Patients with PML were significantly younger than controls. When combining our 10 patients with another 20 from the literature, we found that 17 patients (57%) died from sarcoidosis-associated PML; thus, the fatality rate was 57%. PML during sarcoidosis is often misdiagnosed. It is not associated with severe CD4 lymphocytopenia. Fatality rate is high in comparison with PML associated with other conditions. Interrupting immunosuppression remains the mainstay of treatment.

Continued declining incidence and improved survival of progressive multifocal leukoencephalopathy in HIV/AIDS patients in the current era

To evaluate the situation and perspectives of progressive multifocal leukoencephalopathy (PML) in human immunodeficiency virus (HIV)-infected patients, we investigated changes in the incidence, causes, and long-term outcome of this disease in 72 acquired immunodeficiency syndrome (AIDS) patients who were diagnosed with PML from 1996 to 2011. Patients were classified according to the date of diagnosis in the first (1996-2000, n = 35), second (2001-2006, n = 26), and recent or third highly active antiretroviral therapy (HAART) period (2007-2011, n = 11). Overall, the incidence of PML decreased from 14.8 cases/1,000 patients/year in 1996 to 2.6 in 2005 and 0.8 in 2011, and nearly two-thirds of recent cases (64 %) were observed in HIV patients not attending clinical visits. The baseline median CD4+ count was higher in recently PML-diagnosed patients (77 vs. 86 vs. 101 cells/mm(3); p < 0.01), and this fact was associated with a cerebrospinal fluid (CSF) inflammatory profile (from 11 to 31 to 55 %, p = 0.007) and with a significantly longer survival (attributable death, 54 vs. 35 vs. 36 %, respectively, p < 0.01). Thus, the overall 1-year and 3-year survival rates were 55 and 50 %, respectively, increasing to 79 % at 1 year for patients with CD4+ count above 100 cells/mm(3) at diagnosis. In a Cox regression analysis, an older age (hazard ratio, HR 0.76), a baseline CD4+ count above 100 cells/mm(3) (HR 0.33), and a CSF inflammatory profile (HR 0.12) were significantly associated with a longer survival. The clinical presentation and outcome of PML in AIDS patients continue to change dramatically. Now, a declining incidence and long-term survival is observed.

Favourable outcome of progressive multifocal leukoencephalopathy with mefloquine treatment in combination with antiretroviral therapy in an HIV-infected patient

A 33-year-old man who developed progressive multifocal leukoencephalopathy (PML) with HIV infection is reported. The patient exhibited rapid decline in neurological status after initiation of antiretroviral therapy (ART), which was attributed to the PML-immune re-constitution inflammatory syndrome. Following the administration of mefloquine in combination with ART, the patient's neurological status improved substantially. This case suggests that further investigation of the use of mefloquine might be warranted for treatment of PML in HIV-infected patients.

Natalizumab remains detectable in patients with multiple sclerosis long after treatment is stopped

Natalizumab is frequently used as a treatment for multiple sclerosis (MS). The occurrence of progressive multifocal leukoencephalopathy (PML) in natalizumab-treated patients indicates that its prominent beneficial effects need to be balanced against the risks. Also, cessation of the drug seems to be associated with recurrence of disease activity. Both the moment of rebound disease activity and the outcome of PML are related to clearance of the drug. Specific features of this IgG4 antibody (i.e. half-antibody exchange) may result in underestimated drug levels. Here, we demonstrate natalizumab levels in 10 patients with relapsing MS, using a recently developed sensitive assay. Remarkably, natalizumab was detectable up to 200 days after cessation of therapy.

Immune reconstitution is not a prognostic factor in progressive multifocal leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML) is typically associated with minimal inflammation; however, patients may develop an inflammatory response due to immune reconstitution (IRIS). The authors aimed to determine if characteristics and outcomes of PML are altered in those with IRIS. A retrospective records review was performed on 87 patients diagnosed with PML at Johns Hopkins, 27 of which had a syndrome consistent with IRIS. Gadolinium enhancement on MRI occurred in 44.4% of cases of PML-IRIS versus 5.1% in PML (p<0.05), and thus had low diagnostic sensitivity and specificity. In HIV+ cases, CD4 counts were lower in those who later developed IRIS (mean 34.8 vs. 71.7, p<0.05) and was predictive of the development of IRIS (p<0.05). Improved prognosis was seen with higher cerebrospinal fluid (CSF) white blood cell counts and protein levels, but not for gadolinium enhancement and there were no differences in survival for PML versus PML-IRIS.

Role of CD4 + and CD8 + T-Cell Responses against JC Virus in the Outcome of Patients with Progressive Multifocal Leukoencephalopathy (PML) and PML with Immune Reconstitution Inflammatory Syndrome

Progressive multifocal leukoencephalopathy (PML) is a severe demyelinating disease of the brain caused by JC virus (JCV). To assess the role of CD4(+) and CD8(+) T-cells against JCV in the clinical outcome of PML and PML in the setting of immune reconstitution inflammatory syndrome (IRIS), we tested gamma interferon (IFN-γ) response by enzyme-linked immunosorbent spot (ELISpot) and intracellular cytokine staining (ICS) in 117 subjects, including 66 PML patients with different clinical outcomes. Both assays were concordant and demonstrated that the cellular immune response against JCV is associated with better clinical outcome. PML survivors had an early CD8(+) T-cell response more frequently than PML progressors (100% versus 27.3%; P = 0.001), while only a trend was observed for the early CD4(+) T-cell response between these two groups (80% versus 45.5%; P = 0.18). Although IRIS itself was more frequent in the PML survivor group, there was no difference in IFN-γ-producing CD4(+) and CD8(+) T-cells between IRIS and non-IRIS PML patients, suggesting that T-cells expressing other cytokines likely have a role in the immunopathogenesis of IRIS. ELISpot and ICS assays are useful prognostic markers of PML evolution and may help in the clinical management of these patients.

Spontaneous recovery from progressive multifocal leukoencephalopathy in a patient with non-active sarcoidosis

We report the case of a 50-year-old female patient with non-active sarcoidosis and no kind of immunosuppression, admitted to our hospital because of increasing confusion and focal neurological deficits. Initially a tumor, herpes encephalitis, or neurosarcoidosis were suspected, but surprisingly biopsy revealed progressive multifocal leukoencephalopathy, additionally confirmed by JC-positive PCR in cerebrospinal fluid. Cases of sarcoidosis and progressive multifocal leukoencephalopathy have been reported before. This is the first case of a patient with no sign of active sarcoidosis and without immunosuppressive therapy who recovered spontaneously with a follow-up time of nearly 3 years.