A case report of progressive multifocal leukoencephalopathy in a human T-cell lymphotropic virus type 1-infected hemodialytic patient

Inflammatory progressive multifocal leukoencephalopathy with human T-cell lymphotropic virus-1 coinfection

A middle-aged man with progressive multifocal leukoencephalopathy (PML) in a human T-cell lymphotropic virus type-1 (HTLV-1) carrier on haemodialysis presented with mild dysarthria and ataxia. Brain MRI revealed asymmetric T2-hyperintense lesions in the cerebral white matter, cerebellum and brainstem. A small amount of JC virus (JCV) genome in cerebrospinal fluid was detected by PCR and cerebellar biopsy demonstrated JCV-DNA presence. Pathological findings showed demyelinating lesions and glial cells with mildly enlarged nuclei, accompanied by T-lymphocytes, neutrophils and plasma cell infiltration. The CD4+/CD8+ratio was 0.83. High-dose corticosteroid therapy was effective for inflammatory PML lesions, and the administration of mefloquine combined with mirtazapine led to favourable outcome. The encephalitis in this case is considered to have occurred secondarily to JCV infection in the presence of HTLV-1 infection. Therefore, it is crucial to investigate the presence of HTLV-1 in order to understand the aetiology of this brain inflammation.

An autopsy case of progressive multifocal leukoencephalopathy after rituximab therapy for malignant lymphoma

Progressive multifocal leukoencephalopathy (PML) is a rare fatal demyelinating disease of the central nervous system caused by reactivation of the JC virus (JCV), which is named after the initials of the patient from whom the virus was first isolated. JCV is highly prevalent worldwide, infects humans in early childhood, and the infection persists throughout the course of life in latent form. The present paper deals with the second autopsy case report of rituximab-associated PML in Japan. A 63-year-old woman who had undergone chemotherapy for non-Hodgkin lymphoma developed progressive dysarthria and cerebellar ataxia. Head magnetic resonance imaging (MRI) revealed small, scattered, hyperintense areas in the midbrain, pons and thalamus, and the patient was first diagnosed as having cerebral infarction. Follow-up MRI showed tendency toward cerebellar atrophy and multiple system atrophy cerebellar type was suggested, which we concluded must have coincidentally occurred. It was challenging to perform biopsy due to the location of the foci and the patient's condition. Twelve months later she died of aspiration pneumonia caused by the bulbar lesion. At autopsy, the histological examination suggested the presence of demyelinating foci with numerous foamy macrophages. In the foci, oligodendrocytes with enlarged ground-glass like nuclei were found in a scattered manner and astrocytes with bizarre nuclei were also detected. These findings verified the case as PML. The first diagnosis of cerebral infarction was later withdrawn, although appropriate disorders were not recalled even after testing with various antibodies. The rate of PML development tends to increase after treatment with molecular-targeted therapies, which directly or indirectly attenuate the cellular-mediated immune system. Various novel molecular-targeted and immunosuppressive drugs have been released on the market; the cases of PML have consequently increased. Accordingly, pathologists should keep this disease in mind in the differential diagnosis when neural symptoms newly emerge in patients who are treated with these drugs.

[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 in individuals with minimal or occult immunosuppression

BACKGROUND

Progressive multifocal leukoencephalopathy (PML) is a deadly demyelinating disease of the brain, caused by reactivation of the polyomavirus JC (JCV). PML has classically been described in individuals with profound cellular immunosuppression such as patients with AIDS, haematological malignancies, organ transplant recipients or those treated with immunosuppressive or immunomodulatory medications for autoimmune diseases. METHODS AND CASE REPORTS: The authors describe five HIV seronegative patients with minimal or occult immunosuppression who developed PML including two patients with alcoholic cirrhosis, one with untreated dermatomyositis and two with idiopathic CD4(+) T cell lymphocytopenia. The authors performed a review of the literature to find similar cases.

RESULTS

The authors found an additional 33 cases in the literature. Of a total of 38 cases, seven (18.4%) had hepatic cirrhosis, five (13.2%) had renal failure, including one with concomitant hepatic cirrhosis, two (5.2%) were pregnant women, two (5.2%) had concomitant dementia, one (2.6%) had dermatomyositis, and 22 (57.9%) had no specific underlying diagnosis. Among these 22, five (22.7%) had low CD4(+) T cell counts (0.080-0.294x10(9)/l) and were diagnosed as having idiopathic CD4(+) lymphocytopenia, and one had a borderline CD4(+) T cell count of 0.308x10(9)/l. The outcome was fatal in 27/38 (71.1%) cases within 1.5-120 months (median 8 months) from onset of symptoms, and 3/4 cases who harboured JCV-specific T cells in their peripheral blood had inactive disease with stable neurological deficits after 6-26 months of follow-up.

DISCUSSION

These results indicate that PML can occur in patients with minimal or occult immunosuppression, and one can revisit the generally accepted notion that profound cellular immunosuppression is a prerequisite for the development of PML.