Progressive multifocal leukoencephalopathy complicating untreated chronic lymphatic leukemia: case report and review of the literature

Progressive multifocal leukoencephalopathy as the presenting feature in a patient with occult low-count monoclonal B-cell lymphocytosis

Introduction

Low Count Monoclonal B-Cell Lymphocytosis (LC-MBL) is a relatively poorly understood entity which has been suggested to be very common in asymptomatic adults and possibly related to infectious complications despite not progressing to CLL.

Methods

We describe the first case of Progressive Multifocal Leukoencephalopathy (PML) presenting in a 72-year-old man with LC-MBL but no other immunocompromising conditions.

Results

A diagnosis of PML was confirmed with classic MRI findings in association with a high CSF John Cunningham polyomavirus (JCV) viral load (4.09' 105 copies/mL). An extensive search for underlying immunocompromising conditions only demonstrated LC-MBL representing approximately 4% of total leukocytes (0.2' 109/L).

Discussion

This is the first report of PML in association with LC-MBL. Careful review of peripheral blood flow cytometry results is necessary to identify this disorder. Further study of the epidemiology and infectious complications of LC-MBL are warranted.

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.

Infections with DNA Viruses, Adenovirus, Polyomaviruses, and Parvovirus B19 in Hematopoietic Stem Cell Transplant Recipients and Patients with Hematologic Malignancies

Infections due to adenovirus, polyomaviruses (BK and JC viruses), and parvovirus B19 may not be as common as infections due to other DNA viruses, such as cytomegalovirus in patients with hematological malignancies and the recipients of hematopoietic stem cell transplantation. However, these infections may result in life-threatening diseases that significantly impact patients' recovery, morbidity, and mortality. Treating physicians should be aware of the diseases associated with these viruses, the patient populations at increased risk for complications due to these infections, and the available diagnostic and therapeutic approaches.

Not All Strokes Are Strokes An Example of Diagnostic Confirmation Bias

A 72-year-old woman presented with a complex partial seizure and right hemiparesis, after a four-week history of cognitive decline, apraxia and speech disturbance. She previously had chronic lymphocytic leukaemia (CLL) and had finished chemotherapy one year prior to presentation. She was receiving monthly intravenous immunoglobulins for bronchiectasis. Brain imaging showed hypodensity in the left temporo-parietal regions. Cerebrospinal fluid was positive for the JC virus, leading to a diagnosis of progressive multifocal leucoencephalopathy (PML). She remains alive, eight months following initial presentation. The case was valuable for reflective practice in avoiding diagnostic (confirmation) bias because the treating team pursued an incorrect diagnosis of stroke and secondary seizure after radiology findings appeared consistent with this. Additionally, PML has not previously been reported in individuals with CLL receiving immunoglobulin therapy, and may explain the relatively benign course in this individual patient. This offers a potential research question for disease modifying treatments in PML.

LEARNING POINTS

This case highlights new insights into an uncommon but important condition: always consider progressive multifocal leucoencephalopathy when immunocompromised patients present with neurological symptoms.A full differential diagnosis should always be considered, even in the context of a more 'plausible' diagnosis.Avoid premature closure and confirmation bias as cognitive errors in diagnostic reasoning.

Ten years of R&D and full automation in molecular diagnosis

A 10-year experience of our automated molecular diagnostic platform that carries out 91 different real-time PCR is described. Progresses and future perspectives in molecular diagnostic microbiology are reviewed: why automation is important; how our platform was implemented; how homemade PCRs were developed; the advantages/disadvantages of homemade PCRs, including the critical aspects of troubleshooting and the need to further reduce the turnaround time for specific samples, at least for defined clinical settings such as emergencies. The future of molecular diagnosis depends on automation, and in a novel perspective, it is time now to fully acknowledge the true contribution of molecular diagnostic and to reconsider the indication for PCR, by also using these tests as first-line assays.

Progressive multifocal leukoencephalopathy with bilateral middle cerebellar peduncle lesions confirmed by repeated CSF-JC virus tests and coexistence of JC virus granule cell neuronopathy. Report of a case

A 65 year-old woman with small lymphocytic leukemia presented with subacute cerebellar ataxia. Six months after rituximab chemotherapy, a cranial MRI revealed lesions in the bilateral middle cerebellar peduncles. Both cerebrospinal fluid (CSF) JC virus (JCV)-DNA PCR test on three occasions and brain biopsy were negative. CSF tests were repeated. The fourth test performed 6 months after the onset showed positive JCV-DNA, and a definite diagnosis of progressive multifocal leukoencephalopathy (PML) was made. Neuroimaging of cerebellar atrophy was considered to be coexistence of granule cell neuronopathy. Medication with mirtazapine and mefloquine was temporarily effective for several months. Little are known solitary bilateral MRI lesions of the middle cerebellar peduncle in PML. JCV-PCR test of CSF may be negative at an earlier stage of PML. Repeated CSF tests should be essential to confirming the diagnosis in such cases.

A phase II randomized trial comparing standard and low dose rituximab combined with alemtuzumab as initial treatment of progressive chronic lymphocytic leukemia in older patients: a trial of the ECOG-ACRIN cancer research group (E1908)

Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) patients requiring initial therapy are often older and frailer and unsuitable candidates for standard chemoimmunotherapy regimens. Shorter duration combination monoclonal antibody (mAb) therapy using alemtuzumab and rituximab has been shown to be effective and tolerable treatment for CLL. Standard dose anti-CD20 mAb therapy causes loss of CD20 expression by surviving CLL cells, which can be minimized by decreasing the mAb dose. We report a randomized phase II clinical trial enrolling older (≥ 65 years) patients (median age 76 years, n = 31) with treatment naïve progressive CLL. Patients received 8-12 weeks of standard subcutaneous alemtuzumab with either intravenous standard (375 mg/m(2) weekly)(n = 16) or low dose (20 mg/m(2) 3x week)(n = 15) rituximab. This study was closed before full accrual because the manufacturer withdrew alemtuzumab for treatment of CLL. The overall response rate was 90% with an 45% complete response rate, median progression-free survival of 17.9 months and no significant differences in outcome between the low and standard dose rituximab arms. The major toxicities were cytopenia and infection with one treatment fatality caused by progressive multifocal leukoencephalopathy but no other opportunistic infections. Combination mAb therapy was effective and tolerable treatment for older and frailer patients with progressive CLL, achieving a high rate of complete remissions. These data support the role of mAb in therapy for less fit CLL patients and the further study of low dose higher frequency anti-CD20 mAb therapy as a potentially more effective use of anti-CD20 mAb in the treatment of CLL.

Progressive multifocal leukoencephalopathy and immune reconstitution inflammatory syndrome (IRIS)

Progressive multifocal leukoencephalopathy is a viral encephalitis induced by the John Cunningham (JC) virus, an ubiquitous neurotropic papovavirus of the genus polyomavirus that in healthy people in latency resides in kidney and bone marrow cells. Activation and entry into the CNS were first seen in patients with malignancies of the hematopoietic system and an impaired immune system. During the 1980 and the 1990s with the appearance of human immunodeficiency virus infection in humans, PML was found to be the most important opportunistic infection of the central nervous system. As a result of highly efficient immunosuppressive and immunomodulatory treatments, in recent years, the number of PML cases again increased. PML is prevented by an intact cellular immune response and accordingly immune reconstitution can terminate established disease in the CNS. However, forced immune reconstitution can lead to massive destruction of virus-infected cells. This may result in clinical exacerbation associated with high morbidity and mortality and referred to as PML with immune reconstitution inflammatory syndrome (PML-IRIS). In the present review, we discuss virological properties and routes of infection in the CNS, but mostly focus on the pathology of PML and PML-IRIS and on the role of the immune system in these disorders. We show that PML and PML-IRIS result from predominant JC virus infection of oligodendrocytes and, to a lesser extent, of infected neurons. Inflammation in these encephalitides seems to be driven by a dominant cytotoxic T cell response which is massively exaggerated during IRIS.