Progressive multifocal leukoencephalopathy in Good's syndrome

Progressive multifocal leukoencephalopathy and peripheral neuropathy in a patient with Good's syndrome

Good's syndrome (GS) is an immunodeficiency characterized by thymoma, hypogammaglobulinemia, and impaired T-cell function. Progressive multifocal encephalopathy (PML), an infection caused by JC virus (JCV), usually occurs in patients infected with human immunodeficiency virus (HIV), or in patients on treatment with immunosuppressive or immunomodulatory drugs. There were few reports of PML due to GS, especially with the comorbidity of peripheral neuropathy. We describe a case of an uncommon presentation of PML and peripheral neuropathy in a male who presented with blurred vision, cognitive changes, limb weakness, and numbness over a 4-month period due to GS. To the best of our knowledge, this is the first report of PML and peripheral neuropathy due to GS. This case aims to highlight that it is necessary to consider the possibility of PML due to GS in patients with thymoma and intracranial lesions, and we should focus not only on opportunistic infections of the central nervous system, such as PML, but also on peripheral neuropathy.

Peripheral B Cell Deficiency and Predisposition to Viral Infections: The Paradigm of Immune Deficiencies

In the era of COVID-19, understanding how our immune system responds to viral infections is more pertinent than ever. Immunodeficiencies with very low or absent B cells offer a valuable model to study the role of humoral immunity against these types of infection. This review looks at the available evidence on viral infections in patients with B cell alymphocytosis, in particular those with X-linked agammaglobulinemia (XLA), Good’s syndrome, post monoclonal-antibody therapy and certain patients with Common Variable Immune Deficiency (CVID). Viral infections are not as infrequent as previously thought in these conditions and individuals with very low circulating B cells seem to be predisposed to an adverse outcome. Particularly in the case of SARS-CoV2 infection, mounting evidence suggests that peripheral B cell alymphocytosis is linked to a poor prognosis.

Progressive multifocal leukoencephalopathy associated with thymoma with immunodeficiency: a case report and literature review

Background

The development of progressive multifocal leukoencephalopathy (PML) is associated with severe cellular immunosuppression. Good’s syndrome (GS) is a rare immunodeficiency syndrome related to thymoma, with the development of humoral as well as cellular immunosuppression; however, there are few reports of PML due to GS. One report suggested that the neurological symptoms of PML related to thymoma may be improved by a reduction of immunosuppressive therapy for myasthenia gravis (MG). It is therefore necessary to identify the cause of immunodeficiency in patients with PML to enable an appropriate treatment strategy to be adopted.

Case presentation:

A 47-year-old Japanese woman was admitted with aphasia and gait difficulty. She had an invasive thymoma that had been treated with repeated chemotherapy, including cyclophosphamide. She had also previously been diagnosed with MG (Myasthenia Gravis Foundation of America clinical classification IIa), but her ptosis and limb weakness had completely recovered. On admission, neurological examination revealed motor aphasia and central facial weakness on the right side. Laboratory studies showed severe lymphopenia, decreased CD4+ and CD8+ T cell and CD19+ B cell counts, and reduced levels of all subclasses of immunoglobulins, suggesting GS. Serology for human immunodeficiency virus (HIV) infection was negative. Brain magnetic resonance imaging showed asymmetric multifocal white matter lesions without contrast enhancement. Cerebrospinal fluid real-time polymerase chain reaction for JC virus was positive, showing 6,283,000 copies/mL. We made a diagnosis of non-HIV-related PML complicated with GS and probable chemotherapy-induced immunodeficiency. She then received intravenous immunoglobulin therapy, mirtazapine, and mefloquine, but died of sepsis 46 days after admission.

Conclusions

It is necessary to consider the possibility of immunodeficiency due to GS in patients with PML related to thymoma. Neurologists should keep in mind the risk of PML in MG patients with thymoma, even if the MG symptoms are in remission, and should thus evaluate the immunological status of the patient accordingly.