Characteristics and outcomes of progressive multifocal leukoencephalopathy in hematologic malignancies and stem cell transplant – a case series

Progressive multifocal leukoencephalopathy in the background of chlorambucil treated chronic lymphocytic leukemia: a case report from Nepal

Introduction

Progressive multifocal leukoencephalopathy is a rare manifestation in itself. Although many immunosuppressive states are associated with the disease, its occurrence in the setting of chronic lymphocytic leukaemia treated with chemotherapy is seldom reported to date.

Case presentation

A 67-year-old woman with known chronic lymphocytic leukaemia who was previously receiving chlorambucil treatment was identified as having progressive multifocal leukoencephalopathy; her prognosis is currently good.

Clinical discussion

Although a rare disease in an immunocompromised setting, progressive multifocal leukoencephalopathy often leads to a grave outcome. However, the authors describe a case with a good prognosis to date.

Conclusion

Progressive multifocal leukoencephalopathy should be in differentials in immunocompromised patients with dementia. Given that the later prognosis of the disease is unpredictable, an earlier diagnosis would be better for immunological reconstitution.

Progressive Multifocal Leukoencephalopathy Treated by Immune Checkpoint Inhibitors

OBJECTIVE

Our aim was to assess the real-world effectiveness of immune checkpoint inhibitors for treatment of patients with progressive multifocal leukoencephalopathy (PML).

METHODS

We conducted a multicenter survey compiling retrospective data from 79 PML patients, including 38 published cases and 41 unpublished cases, who received immune checkpoint inhibitors as add-on to standard of care. One-year follow-up data were analyzed to determine clinical outcomes and safety profile. Logistic regression was used to identify variables associated with 1-year survival.

RESULTS

Predisposing conditions included hematological malignancy (n = 38, 48.1%), primary immunodeficiency (n = 14, 17.7%), human immunodeficiency virus/acquired immunodeficiency syndrome (n = 12, 15.2%), inflammatory disease (n = 8, 10.1%), neoplasm (n = 5, 6.3%), and transplantation (n = 2, 2.5%). Pembrolizumab was most commonly used (n = 53, 67.1%). One-year survival was 51.9% (41/79). PML-immune reconstitution inflammatory syndrome (IRIS) was reported in 15 of 79 patients (19%). Pretreatment expression of programmed cell death-1 on circulating T cells did not differ between survivors and nonsurvivors. Development of contrast enhancement on follow-up magnetic resonance imaging at least once during follow-up (OR = 3.16, 95% confidence interval = 1.20-8.72, p = 0.02) was associated with 1-year survival. Cerebrospinal fluid JC polyomavirus DNA load decreased significantly by 1-month follow-up in survivors compared to nonsurvivors (p < 0.0001). Thirty-two adverse events occurred among 24 of 79 patients (30.4%), and led to treatment discontinuation in 7 of 24 patients (29.1%).

INTERPRETATION

In this noncontrolled retrospective study of patients with PML who were treated with immune checkpoint inhibitors, mortality remains high. Development of inflammatory features or overt PML-IRIS was commonly observed. This study highlights that use of immune checkpoint inhibitors should be strictly personalized toward characteristics of the individual PML patient. ANN NEUROL 2023;93:257-270.

Progressive multifocal leukoencephalopathy: epidemiology and spectrum of predisposing conditions

Population-based data on the epidemiology of progressive multifocal leukoencephalopathy, its predisposing conditions and mortality rate are lacking, although such data are crucial to raise awareness among clinicians and to lay foundations for future therapeutic trials in immunomodulating therapies. In our study, patients were identified by interrogating the French national healthcare reimbursement database from 1 January 2008 to 31 December 2017, using progressive multifocal leukoencephalopathy International Classification of Diseases code and a patient's selection algorithm. Overall incidence rate, 1-year all-cause mortality rate and survival patterns were calculated, and factors associated with death were identified using a multivariate Cox proportional hazards regression model. Our cohort is the largest to date, comprising 584 patients with incident progressive multifocal leukoencephalopathy. The overall incidence in France from 2010 to 2017 was stable during the study period at 0.11 per 100 000 person-years, 95% confidence interval [0.10-0.12]. Predisposing diseases were HIV infection (43.7%), followed by haematological malignancies (21.9%), chronic inflammatory diseases (20.2%), solid organ transplantation (4.3%), solid neoplasm (4.1%) and primary immune deficiency (1.5%). The 1-year mortality rate was 38.2%, with a 95% confidence interval (34.2-42.2). In multivariate analysis, factors independently associated with death were older age [adjusted hazard ratio 0.33 (0.20-0.53) for patients aged 20 to 40 compared with patients aged over 60], male gender [adjusted hazard ratio 0.73 (0.54-0.99) for females compared with males] and predisposing immunosuppressive disease, with the highest risk for solid neoplasms [adjusted hazard ratio 4.34 (2.25-8.37)], followed by haematological malignancies [adjusted hazard ratio 3.13 (1.85-5.30)] and HIV infection [adjusted hazard ratio 1.83 (1.12-3.00)], compared with chronic inflammatory diseases. Immune reconstitution inflammatory syndrome was notified in 7.0% of patients. In conclusion, incidence of progressive multifocal leukoencephalopathy is stable in France, and HIV infection remains the main predisposing disease. This large-size cohort uncovers a higher risk of mortality for male patients compared to females, and the worst prognosis for patients with solid neoplasm, while prognosis in patients with haematological malignancies appeared less dismal than in previous studies.

[Clinical effect of allogeneic hematopoietic stem cell transplantation in children with hyper-IgM syndrome]

OBJECTIVES

To evaluate the clinical effect of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in children with hyper-IgM syndrome (HIGM).

METHODS

A retrospective analysis was performed on the medical data of 17 children with HIGM who received allo-HSCT. The Kaplan Meier method was used for the survival analysis of the children with HIGM after allo-HSCT.

RESULTS

After allo-HSCT, 16 children were diagnosed with sepsis; 14 tested positive for virus within 100 days after allo-HSCT, among whom 11 were positive for Epstein-Barr virus, 7 were positive for cytomegalovirus, and 2 were positive for JC virus; 9 children were found to have invasive fungal disease. There were 6 children with acute graft-versus-host disease and 3 children with chronic graft-versus-host disease. The median follow-up time was about 2 years, and 3 children died in the early stage after allo-HSCT. The children had an overall survival (OS) rate of 82.35%, an event-free survival (EFS) rate of 70.59%, and a disease-free survival (DFS) rate of 76.47%. The univariate analysis showed that the children receiving HLA-matched allo-HSCT had a significantly higher EFS rate than those receiving HLA-mismatched allo-HSCT (P=0.019) and that the children receiving HLA-matched unrelated allo-HSCT had significantly higher OS, EFS, and DFS rates than those receiving HLA-mismatched unrelated allo-HSCT (P<0.05). Compared with the children with fungal infection after allo-HSCT, the children without fungal infection had significantly higher EFS rate (P=0.02) and DFS rate (P=0.04).

CONCLUSIONS

Allo-HSCT is an effective treatment method for children with HIGM. HLA-matched allo-HSCT and active prevention and treatment of fungal infection and opportunistic infection may help to improve the prognosis of such children.

Neurologic Infections in Patients on Immunomodulatory and Immunosuppressive Therapies

PURPOSE OF REVIEW

Both broadly immunosuppressive medications and selective immunomodulatory agents that act on particular components of the immune system are increasingly used in the treatment of neurologic and non-neurologic diseases. These therapies predispose patients to particular infections, some of which may affect the nervous system. Therefore, familiarity with the clinical and radiologic features of neurologic infections associated with specific immunomodulatory therapies is of importance for the practicing neurologist. This article reviews these neuroinfectious conditions, as well as other neurologic complications unique to transplant recipients and other patients who are immunocompromised.

RECENT FINDINGS

Diagnosis of infectious pathogens in patients who are immunocompromised may be particularly challenging because a decreased immune response can lead to atypical imaging or laboratory findings. Next-generation sequencing and other novel diagnostic modalities may improve the rate of early identification of neurologic infections in patients who are immunocompromised and ultimately ameliorate outcomes in this vulnerable population.

SUMMARY

A broad range of bacterial, viral, fungal, and parasitic infections of the nervous system can complicate solid organ and hematopoietic cell transplantation as well as other forms of immunocompromise. In addition to neurologic infections, such patients are at risk of neurotoxic and neuroinflammatory complications related to immunomodulatory and immunosuppressive therapies. Early recognition of infectious and noninfectious complications of immunocompromise is essential to guide appropriate treatment, which can include antimicrobial therapy and, in some cases, withdrawal of the predisposing medication with a transition to an alternative regimen.

Pembrolizumab for treatment of progressive multifocal leukoencephalopathy in primary immunodeficiency and/or hematologic malignancy: a case series of five patients

Progressive multifocal leukoencephalopathy is a rare opportunistic infection of the brain by John Cunningham polyomavirus in immune-compromised patients. In cases where no overt option for immune reconstitution is available [e.g., in patients with primary immunodeficiency (PID)], the disease is lethal in the majority of patients. Immune checkpoint inhibition has been applied in recent years with mixed outcomes. We present four novel patients and the follow-up of a previously published patient suffering from progressive multifocal leukoencephalopathy (PML) due to PID and/or hematologic malignancy who were treated with the immune checkpoint inhibitor pembrolizumab. In two patients with PID, symptoms improved and stabilized. One patient died because of worsening PML another of intracranial hemorrhage which was unrelated to PML or its treatment with pembrolizumab. The fifth patient suffered from PID and died of a pre-existing immune dysregulation, possibly exacerbated by pembrolizumab. The long-term follow-up of the first patient provides support for therapeutic decisions during this therapy and is the longest published clinical course of a patient with checkpoint inhibition for PML. We conclude that pembrolizumab can control PML symptoms long term in a subgroup of patients with PID, in our cases for 21 and 36 months. However, therapy must be started early because symptoms are only partially reversible. In light of severe adverse events, application of pembrolizumab is only justified if the prognosis for the individual patient is very poor.

Beyond Cytomegalovirus and Epstein-Barr Virus: a Review of Viruses Composing the Blood Virome of Solid Organ Transplant and Hematopoietic Stem Cell Transplant Recipients

Viral primary infections and reactivations are common complications in patients after solid organ transplantation (SOT) and hematopoietic stem cell transplantation (HSCT) and are associated with high morbidity and mortality. Among these patients, viral infections are frequently associated with viremia. Beyond the usual well-known viruses that are part of the routine clinical management of transplant recipients, numerous other viral signatures or genomes can be identified in the blood of these patients. The identification of novel viral species and variants by metagenomic next-generation sequencing has opened up a new field of investigation and new paradigms. Thus, there is a need to thoroughly describe the state of knowledge in this field with a review of all viral infections that should be scrutinized in high-risk populations. Here, we review the eukaryotic DNA and RNA viruses identified in blood, plasma, or serum samples of pediatric and adult SOT/HSCT recipients and the prevalence of their detection, with a particular focus on recently identified viruses and those for which their potential association with disease remains to be investigated, such as members of the Polyomaviridae, Anelloviridae, Flaviviridae, and Astroviridae families. Current knowledge of the clinical significance of these viral infections with associated viremia among transplant recipients is also discussed. To ensure a comprehensive description in these two populations, individuals described as healthy (mostly blood donors) are considered for comparative purposes. The list of viruses that should be on the clinicians' radar is certainly incomplete and will expand, but the challenge is to identify those of possible clinical significance.

Progressive Multifocal Leukoencephalopathy: Current Insights

Cases of PML should be evaluated according to predisposing factors, as these subgroups differ by incidence rate, clinical course, and prognosis. The three most significant groups at risk of PML are patients with hematological malignancies mostly previously treated with immunotherapies but also untreated, patients with HIV infection, and patients using monoclonal antibody (mAb) treatments. Epidemiological data is scarce and partly conflicting, but the distribution of the subgroups appears to have changed. While there is no specific anti-JCPyV treatment, restoration of the immune function is the most effective approach to PML treatment. Research is warranted to determine whether immune checkpoint inhibitors could benefit certain PML subgroups. There are no systematic national or international records of PML diagnoses or a risk stratification algorithm, except for MS patients receiving natalizumab (NTZ). These are needed to improve PML risk assessment and to tailor better prevention strategies.

Progressive multifocal leukoencephalopathy in Finland: a cross-sectional registry study

Objective

To investigate if progressive multifocal leucoencephalopathy (PML) incidence has increased in Finland like in the neighbouring Sweden.

Methods

National administrative registries were searched for all PML admissions aged 16 years or more in 2004–2014 on all neurological and internal medicine wards in Finland. The mortality data of the patients was extracted from the national causes of death registry. National level data on annual predisposing drug use was obtained from the national pharmaceutical authority.

Results

We identified 35 PML cases (57% male) with a peak in 2010–2011 that amounted to 49% of all cases. The annual incidence for the entire study period was 0.072/100,000 person-years (95% CI 0.050–0.10) with no temporal trend (p = 0.18). Mean age was 57 years (22–88 years) with no sex difference (p = 0.42). Neoplasms (60%), HIV infection (17%) and systemic connective tissue disorders (CTD, 14%) were the most common predisposing conditions. MS was recorded in three cases (9%). The national level use of drugs that predispose to PML increased during the study period, with the exceptions of alemtuzumab and fludarabine. Overall survival was 85% at 90 days, 79% at 1 year, and 66% at 5 years. Survival was worst in patients with malignancy and best in patients with CTD.

Conclusions

PML most often occurs in patients with malignancies and patients with HIV or CTD cover a third. PML incidence in Finland is lower than in Sweden and shows no temporal trend despite increasing use of predisposing drugs. Mortality after PML varies according to the predisposing condition.

Electronic supplementary material

The online version of this article (10.1007/s00415-018-09167-y) contains supplementary material, which is available to authorized users.