Prolonged Immunosuppression in Relapsed, Refractory Multiple Myeloma Leading to Cerebral Toxoplasmosis and Progressive Multifocal Leukoencephalopathy

Cerebral toxoplasmosis in a patient with multiple myeloma

Background:

Cerebral toxoplasmosis is a rare complication of relapsed/refractory multiple myeloma (MM) after autologous stem cell transplant (SCT). Imaging characteristics can be helpful in leading to rapid diagnosis and treatment.

Case Description:

A 76-year-old man with relapsed/refractory IgA kappa MM status post autologous SCT who presented to the hospital with altered mental status. His hospital course was complicated by rapid decompensation to obtundation requiring intubation. Magnetic resonance imaging (MRI) of the brain revealed numerous ring-enhancing lesions with eccentric target signs, which were concerning for cerebral toxoplasmosis. Diagnosis was confirmed with positive toxoplasma cerebrospinal fluid polymerase chain reaction test.

Conclusion:

Cerebral toxoplasmosis should be considered in the differential diagnosis for MM patients who present with altered mental status and neurologic findings. The ring-enhancing lesion with eccentric target sign on MRI can be helpful in the diagnosis of cerebral toxoplasmosis.

Progressive multifocal leukoencephalopathy in patients with immunovirological control and at least 6 months of combination antiretroviral therapy

OBJECTIVES AND METHODS

: Progressive multifocal leukoencephalopathy (PML) has rarely been reported in people with HIV (PWH) with long-term HIV immune-virological control. We describe the clinical and biological characteristics of patients with confirmed PML among PWH with a CD4+ cell count more than 200 cells/μl and an undetectable HIV RNA viral load after at least 6 months of combined antiretroviral therapy (cART) at the time of PML diagnosis, in the large French multicenter Dat'AIDS cohort.

RESULTS

: Among 571 diagnoses of PML reported in the Dat'AIDS cohort between 2000 and 2019, 10 cases (1.75%) occurred in PWH with a CD4+ cell count greater than 200 cells/μl and an undetectable HIV RNA viral load after at least 6 months of cART. Median CD4+ cell count at PML diagnosis was 395 cells/μl (IQR 310-477). The median duration between the last detectable HIV viral load and the PML diagnosis was 41.1 months (IQR 8.2-67.4). Only one patient treated with rituximab-based chemotherapy for a large B-cell lymphoma had an established risk factor for PML. Among the nine other patients with no apparent severe immunodeficiency, multiple factors of impaired immunity could have led to the development of PML: hepatitis C virus (HCV) co-infection (n = 6), cirrhosis (n = 4), HHV-8 co-infection (n = 3) with Kaposi's sarcoma (n = 2) in association with Castleman's disease (n = 1) and indolent IgA multiple myeloma (n = 1).

CONCLUSION

: This study highlights that factors other than low CD4+ cell count and high HIV viral load may be associated with the occurrence of PML. Further studies are warranted to investigate in greater detail the immunologic characteristics of PWH with immune-virological control who develop PML.

Progressive multifocal leukoencephalopathy in multiple myeloma. A literature review and lessons to learn

Progressive multifocal leukoencephalopathy (PML) is a rare opportunistic infection with high mortality rate usually seen in the context of immunosuppression. Although cases have been reported largely in patients with HIV/AIDS, following the use of monoclonal antibodies and occasionally in haematological malignancies, there is no review to date of patients with smouldering or treated myeloma who developed PML. Here, we conducted a literature search of PML cases in patients with multiple myeloma (MM), analyse patient and disease characteristics and describe the possible mechanisms that could lead to the development of PML. The lack of data and case reports until 2010 may indicate that PML in MM is underdiagnosed. Simultaneously, with an expanding field of new therapeutic options, patients with MM live longer, albeit continually immunosuppressed, and at risk of opportunistic infections. Emerging new treatments for PML in the horizon render the need to look out for this complication mandatory, and more case reports are needed to enrich our knowledge in this field.

Pomalidomide-associated progressive multifocal leukoencephalopathy in multiple myeloma: cortical susceptibility-weighted imaging hypointense findings prior to clinical deterioration

Although there are several case reports of progressive multifocal leukoencephalopathy (PML) in multiple myeloma (MM), there are few reports of cases associated with pomalidomide. Here, we report the case of a 69-year-old female who had received 41 cycles of pomalidomide and dexamethasone treatment for relapsed/refractory IgG-κ MM presented with right-hand weakness; she was diagnosed as pomalidomide-associated PML. Fluid-attenuated inversion recovery (FLAIR) on admission showed high signals in the bilateral front-parietal lobe white matter, with multiple punctate lesions in the vicinity of the main lesions. These punctate pattern findings on FLAIR were similar to that of natalizumab-associated PML. Susceptibility weighted imaging (SWI) showed hypointense rims within the cortex at unaffected sites, in the initial stages. Subsequently, the clinical manifestations deteriorated, and the FLAIR images showed new hyperintense white matter lesions at the sites where cortical SWI hypointense rims were detected on the initial MRI examination. Our patient's serial MRI findings suggest that cortical SWI hypointense rims appear prior to the visible demyelinating white matter lesions in patients with PML.