Failure of mefloquine therapy in progressive multifocal leukoencephalopathy: report of two Japanese patients without human immunodeficiency virus infection

Progressive multifocal leukoencephalopathy secondary to idiopathic CD4 lymphocytopenia treated with pembrolizumab

BACKGROUND

Progressive multifocal leukoencephalopathy (PML) is a rare demyelinating disease due to a lytic infection of oligodendrocytes caused by John Cunningham polyoma virus (JCV) infection. Idiopathic CD4+ T-cell lymphocytopenia (ICL) is a very rare cause of PML.

METHODS

We present an individual with PML secondary to ICL treated with 3 doses of pembrolizumab, a Programmed-Death-1 Immune Checkpoint Inhibitor following with complete resolution of symptoms and conduct a review of the literature.

CONCLUSION

This report illustrates the objective clinical and radiological improvement in a patient with PML due to ICL and suggests further study of immune checkpoint inhibitors as potential treatment for patients with PML.

Progressive multifocal leukoencephalopathy without overt immunosuppression

Progressive multifocal leukoencephalopathy (PML) is a central nervous system disease caused by the human polyomavirus 2 that usually occurs in a setting of immunodeficiency. PML without overt immunosuppression is considered a rare occurrence but has been described in multiple previous case reports and series. Its prevalence, overall frequency, and prognosis are largely unknown. This is a single-center retrospective review of all University of Florida cases with the ICD10 PML diagnosis code (A81.2). PML without overt immunosuppression was defined as absence of human immunodeficiency virus (HIV) infection, hematological malignancy, immunomodulatory/-suppressive medications, autoimmune conditions with a propensity for PML (sarcoidosis, systemic lupus erythematosus). Cases that did not fulfill criteria for clinically or histologically definite PML were excluded. Of 52 patients with the ICD10 code A 81.2, 17 fulfilled definite diagnostic criteria for PML. Overt immunosuppression was identified in 15/17 (88.2%) cases (10/17 (58.8%): human immunodeficiency virus; 5/17 (29.4%): immunomodulatory/-suppressive medication). Two/seventeen (11.8%) cases were consistent with PML without overt immunosuppression. Possible contributing factors were a preceding dog bite and mild hypogammaglobulinemia M (39 mg/dL) in case 1 and significant alcohol use without evidence for liver disease in case 2. Both cases were fatal within 6 (case 1) and 2 (case 2) months. The results suggest that PML without overt immunosuppression may be more common than previously described. Therefore, PML should be considered even in the absence of overt immunosuppression if clinical and radiographic findings are suggestive of the diagnosis.

Antivirals against human polyomaviruses: Leaving no stone unturned

Human polyomaviruses (HPyVs) encompass more than 10 species infecting 30%-90% of the human population without significant illness. Proven HPyV diseases with documented histopathology affect primarily immunocompromised hosts with manifestations in brain, skin and renourinary tract such as polyomavirus-associated nephropathy (PyVAN), polyomavirus-associated haemorrhagic cystitis (PyVHC), polyomavirus-associated urothelial cancer (PyVUC), progressive multifocal leukoencephalopathy (PML), Merkel cell carcinoma (MCC), Trichodysplasia spinulosa (TS) and pruritic hyperproliferative keratinopathy. Although virus-specific immune control is the eventual goal of therapy and lasting cure, antiviral treatments are urgently needed in order to reduce or prevent HPyV diseases and thereby bridging the time needed to establish virus-specific immunity. However, the small dsDNA genome of only 5 kb of the non-enveloped HPyVs only encodes 5-7 viral proteins. Thus, HPyV replication relies heavily on host cell factors, thereby limiting both, number and type of specific virus-encoded antiviral targets. Lack of cost-effective high-throughput screening systems and relevant small animal models complicates the preclinical development. Current clinical studies are limited by small case numbers, poorly efficacious compounds and absence of proper randomized trial design. Here, we review preclinical and clinical studies that evaluated small molecules with presumed antiviral activity against HPyVs and provide an outlook regarding potential new antiviral strategies.

Progressive multifocal leukoencephalopathy after CAR T therapy

Progressive multifocal leukoencephalopathy (PML) remains a life-threatening central nervous system infection in immunocompromised patients. Although outcomes have improved in cases that immune reconstitution is feasible with anti-retroviral therapy (ART) in HIV + patients or natalizumab removal in those with multiple sclerosis, in individuals with hematological malignancies, the prognosis is usually dismal. Anti-viral treatments have been largely ineffective, but immunotherapy-based approaches with checkpoint inhibitors and adoptive virus-specific T cells' transfer are currently explored in clinical trials. PML has not been described as a cause of encephalopathy after CAR T therapy. We report the first case of PML 7 months after lymphodepleting chemotherapy with fludarabine/cyclophosphamide and anti-CD19-directed CAR T therapy in a patient with relapsed diffuse large B-cell lymphoma who relapsed fast after a previous autologous hematopoietic stem cell transplant. She remains alive 12 months after diagnosis with stabilization of her symptoms with a combination of therapies targeting viral replication and immunotherapy.

The Use of Antimalarial Drugs against Viral Infection

In recent decades, drugs used to treat malaria infection have been shown to be beneficial for many other diseases, including viral infections. In particular, they have received special attention due to the lack of effective antiviral drugs against new emerging viruses (i.e., HIV, dengue virus, chikungunya virus, Ebola virus, etc.) or against classic infections due to drug-resistant viral strains (i.e., human cytomegalovirus). Here, we reviewed the in vitro/in vivo and clinical studies conducted to evaluate the antiviral activities of four classes of antimalarial drugs: Artemisinin derivatives, aryl-aminoalcohols, aminoquinolines, and antimicrobial drugs.

Successful treatment of non-HIV progressive multifocal leukoencephalopathy: case report and literature review

BACKGROUND

Progressive multifocal leukoencephalopathy (PML) is a subacute onset demyelinating disease caused by JC virus and characterized by multifocal involvement of the subcortical white matter and cerebellar hemispheres or peduncles on magnetic resonance imaging (MRI). However, non-HIV PML patients with brain lesions limited to the cerebellum and brainstem have not been well characterized.

METHODS

We report a 68-year-old man with systemic lupus erythematosus under treatment with immunosuppressants who developed non-HIV PML with brain lesions limited to the cerebellum and brainstem and successfully treated with a combination of mefloquine and mirtazapine. We performed a literature review to characterize patients with non-HIV PML with brain lesions limited to the cerebellum and brainstem.

RESULTS

Eight cases with non-HIV brainstem/cerebellar form PML were identified including our case. All cases had compromised status related underlying diseases. Four (50%) had a good prognosis. Five cases were treated, including 3 with favourable outcomes. Between the good prognosis group (n = 4) and the poor prognosis group (n = 4), treatment status for PML and the interval between the initial manifestation and diagnosis did not differ. Among those who performed contrast-enhanced brain imaging, lesion enhancement was related to good prognosis (good prognosis group vs. poor prognosis group; 100% vs. 0%).

CONCLUSION

PML should be considered in the differential diagnosis of brain lesions limited to the cerebellum and brainstem in immunocompromised patients. The presence of immune response against JC virus and inflammatory reactions may indicate good prognosis in non-HIV brainstem/cerebellar form PML.

A controlled inflammation and a regulatory immune system are associated with more favorable prognosis of progressive multifocal leukoencephalopathy

OBJECTIVE

In the present study, we analyzed the inflammatory profiles of brain tissues obtained from patients with progressive multifocal leukoencephalopathy (PML) due to John Cunningham (JC) virus infection to identify potential prognostic factors.

METHODS

The study included seven patients (two men, five women) who had been pathologically diagnosed with PML, and all of whom were HIV negative. Fixed brain samples were analyzed via hematoxylin and eosin (HE) staining and Klüver-Barrera (KB) staining. We then performed immunohistochemistry (IHC) specific to JC virus capsid proteins (VP1 and VP2/3) and lymphocyte surface markers (CD4, CD8, CD138, and PD-1).

RESULTS

The mean age at onset was 53.4, while the mean duration until biopsy/autopsy was 4.7 months. Four patients were included in the good prognosis (GP) group, while three were included in the poor prognosis (PP) group. Pathological analysis revealed a significantly larger number of CD4-positive T-cell infiltrations (P = .029) in the GP group, along with a preserved CD4:CD8 ratio. Larger numbers of CD138-positive plasma cells were also observed in the GP group (P = .029) than in the PP group. Linear regression analyses revealed a significant association between the numbers of CD138-positive plasma cells and PD-1-positive cells (R² = 0.80).

CONCLUSIONS

Viral loads in the cerebrospinal fluid, a controlled inflammatory response mediated by CD4- and CD8-positive T cells, and plasma cells are associated with PML prognosis. Our findings further indicate that regulatory plasma cells may regulate inflammatory T-cell activity via a PD-1/PD-L1 immuno-checkpoint pathway, thereby protecting the uninfected brain from excessive immune-mediated damage during an active JC virus infection.

Drug-associated progressive multifocal leukoencephalopathy: a clinical, radiological, and cerebrospinal fluid analysis of 326 cases

The implementation of a variety of immunosuppressive therapies has made drug-associated progressive multifocal leukoencephalopathy (PML) an increasingly prevalent clinical entity. The purpose of this study was to investigate its diagnostic characteristics and to determine whether differences herein exist between the multiple sclerosis (MS), neoplasm, post-transplantation, and autoimmune disease subgroups. Reports of possible, probable, and definite PML according to the current diagnostic criteria were obtained by a systematic search of PubMed and the Dutch pharmacovigilance database. Demographic, epidemiologic, clinical, radiological, cerebrospinal fluid (CSF), and histopathological features were extracted from each report and differences were compared between the disease categories. In the 326 identified reports, PML onset occurred on average 29.5 months after drug introduction, varying from 14.2 to 37.8 months in the neoplasm and MS subgroups, respectively. The most common overall symptoms were motor weakness (48.6 %), cognitive deficits (43.2 %), dysarthria (26.3 %), and ataxia (24.1 %). The former two also constituted the most prevalent manifestations in each subgroup. Lesions were more often localized supratentorially (87.7 %) than infratentorially (27.4 %), especially in the frontal (64.1 %) and parietal lobes (46.6 %), and revealed enhancement in 27.6 % of cases, particularly in the MS (42.9 %) subgroup. Positive JC virus results in the first CSF sample were obtained in 63.5 %, while conversion after one or more negative outcomes occurred in 13.7 % of cases. 52.2 % of patients died, ranging from 12.0 to 83.3 % in the MS and neoplasm subgroups, respectively. In conclusion, despite the heterogeneous nature of the underlying diseases, motor weakness and cognitive changes were the two most common manifestations of drug-associated PML in all subgroups. The frontal and parietal lobes invariably constituted the predilection sites of drug-related PML lesions.

[A case of progressive multifocal leukoencephalopathy with Takayasu arteritis and indolent adult T-cell lymphoma/leukemia]

A 65-year-old man with Takayasu arteritis in a stable condition was admitted to our hospital because of rapid progressive dementia. Brain FLAIR/T2-weighted magnetic resonance images revealed high signal intensity in the diffuse subcortical white matter. John Cunningham virus (JCV) genome in cerebrospinal fluid was detected by polymerase chain reaction. Finally, progressive multifocal leukoencephalopathy was diagnosed definitely by brain biopsy. In addition, the patient was found to be complicated by chronic/smoldering adult T-cell leukemia/lymphoma. The administration of mefloquine with mirtazapine was early started within two months after the onset. However, the combination treatment led to no improvement in symptoms and lesion size. The patient died six months after the onset. Therefore, this case suggested that both of HTLV-I infection and B cell abnormalities due to Takasasu arteritis impaired the therapeutic effect.

Progressive Multifocal Leukoencephalopathy Localized in the Cerebellum and Brainstem Associated with Idiopathic CD4(+) T Lymphocytopenia

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease that favors the cerebrum and typically occurs in immunosuppressed patients. We herein report the case of a 66-year-old man with PML, idiopathic CD4(+) T lymphocytopenia (ICL), and chronic renal failure. Cranial magnetic resonance imaging (MRI) showed a crescent-shaped lesion in the left cerebellum, brainstem, and middle cerebellar peduncle. Although the patient did not present with HIV infection, collagen diseases, or tumors, JC virus DNA was detected in the cerebrospinal fluid. Clinicians should consider PML and ICL in the differential diagnosis if the patient develops progressive ataxia and a crescent-shaped cerebellar lesion on MRI.

Progressive Multifocal Leukoencephalopathy with Balanced CD4/CD8 T-Cell Infiltration and Good Response to Mefloquine Treatment

A 53-year-old man was admitted for sub-acute progressive dementia and Gerstmann syndrome. MRI demonstrated lesions in the white matter involving the left parietal lobe, accompanied by speckled or faint linear peripheral enhancement. Brain biopsy revealed JC virus infection in oligodendrocytes and balanced infiltration of CD8+ and CD4+ T lymphocytes. We diagnosed progressive multifocal leukoencephalopathy (PML) with controlled inflammation. The finding of CD4/CD8 T cells in the infected PML brain suggested therapeutically valuable immune system involvement, which we decided to preserve by withholding corticosteroids. We treated the patient with risperidone, cytarabine and mefloquine to suppress virus replication, but not with the corticosteroid that is conventionally used in inflammatory PML cases. The patient was discharged three months after admission, and one year later, his score on the Mini-Mental State Examination had recovered to 26/30, from 5/30 on admission.

Rapid reduction of viruria and stabilization of allograft function by fusidic acid in a renal transplant recipient with JC virus-associated nephropathy

JC virus (JCV)-associated nephropathy has been increasingly recognized as a cause of allograft dysfunction with graft loss in renal transplant recipients. Like many other opportunistic viral infections in transplant recipients, there are currently limited therapeutic options for this condition. Fusidic acid has previously been reported to exhibit antiviral activity against JCV in in vitro assays. We report the first in vivo study to document the rapid reduction of JC viruria and stabilization of allograft function by oral fusidic acid (fusidate sodium) in a deceased donor renal transplant recipient with JCV-associated nephropathy and acute allograft dysfunction which did not improve initially to surgical relief of hydronephrosis and reduction of immunosuppressants. Rapid reduction of JC viruria detected by quantitative PCR and stabilization of renal function were observed. Fusidic acid has several practical advantages in this clinical setting, including a low EC50 against JCV, high plasma C max, long half-life, availability of both oral and intravenous formulations, excellent oral bioavailability, good patient tolerability, and lack of serious drug interactions with other drugs taken by renal transplant recipients. Further mechanistic and clinical studies are necessary to evaluate this treatment option for JCV-associated nephropathy.

Rituximab-associated progressive multifocal leukoencephalopathy derived from non-Hodgkin lymphoma: neuropathological findings and results of mefloquine treatment

A 66-year-old man with non-Hodgkin lymphoma (NHL) developed progressive multifocal leukoencephalopathy (PML) after undergoing chemotherapy including rituximab. Although the administration of mefloquine at a dose of 500 mg weekly temporarily led to a dramatic decrease in the copy number of JC Virus DNA in the cerebrospinal fluid, the patient's symptoms gradually worsened. The CD4(+) T count remained continuously low, at least until approximately five months after the last cycle of chemotherapy. A postmortem examination performed 10 months after the onset of PML disclosed a severe condition associated with rituximab-treated PML originating from NHL and a high mefloquine concentration in the brain. The accumulation of further data regarding mefloquine treatment in PML cases may help to elucidate the optimal dosage and time window for effectively treating PML.

Progressive multifocal leukoencephalopathy in patients with a hematological malignancy: review of therapeutic options

In the context of 2 patients with hematological malignancy who developed progressive multifocal leukoencephalopathy (PML), we review the current therapeutic options for this serious complication. Both patients had lymphoma and had been pretreated with the antibody rituximab. Diagnosis of PML was obtained upon the detection of the JC virus. The outcome was fatal in both cases. So far, no standard therapeutic approach for JC virus infection has been established in HIV-negative patients with hematological malignancies and the outcome is usually fatal. Serotonin receptor antagonists might have a beneficial effect by blocking the virus from entering the cells. Although hopes for the efficacy of mefloquine were disappointed by the results of 1 study, several case reports describe improvements in neurological impairment when this drug is administered. Taking the desperate situation of this patient group into consideration, the combination of mirtazapine and mefloquine might be worthy of an attempt.

[Ineffective mefloquine therapy in progressive multifocal leukoencephalopathy complicated with malignant lymphoma: finding and usefulness of susceptibility-weighted imaging]

A 57-year-old woman presented with motor and cognitive impairments under treatment for cryptogenic organizing pneumonia with immunosuppressive agents. Magnetic resonance imaging showed widespread signal abnormalities in the cerebral white matter. Susceptibility-weighted imaging showed attenuated contrast of the cerebral medullary vein in the lesions, and (18)F-fluorodeoxyglucose-positron emission tomography ((18)F-FDG-PET) revealed decreased uptake at the same site and increased uptake in multifocal lung involvements. Lung biopsy findings were consistent with diffuse large B-cell lymphoma. Polymerase chain reaction for JC Virus DNA in cerebrospinal fluid yielded positive results. Based on these findings, the present case was given a diagnosis of progressive multifocal leukoencephalopathy (PML). The patient was treated with oral mefloquine, but her respiratory condition deteriorated and chemotherapy was required to prevent further deterioration. As a result, chemotherapy to treat lymphoma could not result in beneficial immune reconstitution, PML continued to progress despite mefloquine treatment, and the patient developed decorticate posture. The efficacy of mefloquine in patients with non-HIV-associated PML warrants further investigation.

Mefloquine improved progressive multifocal leukoencephalopathy in a patient with immunoglobulin A nephropathy

We describe a patient with immunoglobulin A nephropathy who was diagnosed with progressive multifocal leukoencephalopathy (PML) and successfully treated with mefloquine, an antimalarial medication. A 67-year-old man with immunoglobulin A nephropathy presented to the hospital emergency room with fever and generalized tonic-clonic seizure. Cerebrospinal fluid (CSF) nested polymerase chain reaction (PCR) was positive for John Cunningham virus and brain MRI displayed high signal intensity in the white matter in the right parietal lobe without gadolinium enhancement. Tapering of prednisone did not arrest the disease progression and a new lesion was detected on the cerebellum. Administration of mefloquine stopped lesion progression and resulted in dramatic clinical improvement. The CSF nested PCR for the John Cunningham virus also became negative. In reviewing the literature, mefloquine has had a heterogeneous effect in PML patients, and P-glycoprotein polymorphism and proper dosage could contribute to the various effects seen. Mefloquine may be a favorable treatment option in some patients with PML, and P-glycoprotein polymorphism may play an important role in its efficacy. More large studies in other ethnic groups including polymorphism studies for the gene encoding P-glycoprotein (ABCB1/MDR1) and taking into account various underlying conditions with secondary immunosuppression should be carried out to investigate whether mefloquine is effective for treating PML.