An unusual course of progressive multifocal leukoencephalopathy in a patient with idiopathic CD4+ T lymphocytopenia

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.

Criptococosis y linfocitopenia T CD4 idiopática: Reporte de un caso

La linfocitopenia T CD4 idiopática (LCI) es un síndrome clínico inusual que se caracteriza por un déficit de células T CD4+ circulantes en ausencia de infección por VIH u otra condición de inmunosupresión. Los pacientes con dicha enfermedad pueden presentarse asintomáticos o con infecciones oportunistas, las más frecuentes son por criptococo, micobacterias o virales como herpes zoster. Presentamos el caso de un hombre de 32 años, sin antecedentes, en quien se descartó infección por retrovirus, con recuento de linfocitos T CD4+ menor a 300 células/m3; se diagnosticó LCI posterior al diagnóstico de criptococomas cerebrales mediante hallazgos imagenológicos los cuales fueron congruentes con estudios microbiológicos.

T cell deficiencies as a common risk factor for drug associated progressive multifocal leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML) is a disease of the central nervous system caused by neuropathogenic prototypes of ubiquitous community-acquired JC virus (JCV). The disease became of particular concern following its association with certain therapies that modulate immune system function without heavy immunosuppression. Due to lack of prophylactic/treatment options and poor outcomes, which often include severe disability or death, PML is a considerable concern for development of new drugs that interfere with immune system functions. In this review of clinical and research findings, we discuss the evidence that deficiencies in CD4⁺ T helper cells, cytotoxic CD8⁺ T cells, and interferon gamma are of crucial importance for development of PML under a variety of circumstances, including those associated with use of various drugs, regardless of differences in their mechanisms of action. These deficiencies apparently enable transformation of the harmless JCV archetype into neuropathogenic prototypes, but the site(s), and the mechanisms, of this transformation are yet to be elucidated. Here we discuss the evidence for brain as one of the sites of this transformation, and propose a model of PML pathogenesis that emphasizes the central role of T cell deficiencies in the two life cycles of the JCV, one non-pathogenic and one neuropathogenic. Finally, we conclude that the development of clinical grade T cell functional tests and more consistent use of already available laboratory tests for T cell subset analysis would greatly aid the effort to more accurately predict and assess the magnitude of PML risk for concerned therapeutic interventions.

Idiopathic CD4 lymphocytopenia: Pathogenesis, etiologies, clinical presentations and treatment strategies

BACKGROUND

Idiopathic CD4 lymphocytopenia (ICL) is a rare condition characterized by an unexplained deficit of circulating CD4 T cells leading to increased risk of serious opportunistic infections. The pathogenesis, etiology, clinical presentation, and best treatment options remain unclear.

OBJECTIVE

To describe the clinical presentation, treatment strategies, and outcome of patients with ICL seen in a single referral center.

METHODS

In a retrospective study, from January 1993 to January 2014, the demographic characteristics, clinical presentation, and treatments of patients diagnosed with ICL were reviewed.

RESULTS

Twenty-four patients (14 female [58%] and 10 male [42%]) were evaluated. The mean age was 45 ± 17.6 years (range 7-76 years). Mean CD4 and CD8 T-cell counts at the time of diagnosis were 119 ± 84/mm³ (range 4-294/mm³) and 219 ± 258/mm³ (range 7-630/mm³), respectively. Seventeen patients (71%) had opportunistic infections, 4 (17%) had malignancies, and 3 (13%) had unexplained demyelinating disease and neurologic problems. Most patients had normal levels of immunoglobulins. Thirteen patients had abnormally low to absent response to phytohemagglutinin, concanavalin A, and antigens (candida and tetanus). Three patients had resolution of warts and 1 had mycobacterial lung infection on interleukin-2 with increases in CD4 count. The 11 patients on trimethoprim and sulfamethoxazole had no further hospital admissions for infections.

CONCLUSION

The pathogenesis of ICL remains unclear. Although only some patients are healthy, most patients present with opportunistic infections. There is no known standard treatment aside from prophylactic antibiotics.

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.

[A case of cerebellar brainstem form of progressive multifocal leukoencephalopathy associated with idiopathic CD4+ lymphocytopenia]

A 77-year-old woman presented with a 6-month history of slowly progressive cerebellar ataxia. T2-weighted MRI showed high signal intensity in the left upper dorsal pons and bilateral middle cerebellar peduncles. JC virus (JCV) DNA was detected in cerebrospinal fluid (CSF). The patient had no HIV infection, collagen disease, or a history of immunosuppressive treatment, but she was found to have CD4+ lymphocytopenia. We made a diagnosis of cerebellar brainstem form of progressive multifocal leukoencephalopathy (PML) presenting as cerebellar ataxia, which was presumably associated with idiopathic CD4+ lymphocytopenia. Following the treatment with mefloquine, the patient slightly improved clinically and JCV-DNA became negative in CSF.

Idiopathic CD4 lymphocytopenia: clinical and immunologic characteristics and follow-up of 40 patients

Idiopathic CD4 T lymphocytopenia (ICL) is a rare and severe condition with limited available data. We conducted a French multicenter study to analyze the clinical and immunologic characteristics of a cohort of patients with ICL according to the Centers for Disease Control criteria.We recruited 40 patients (24 female) of mean age 44.2 ± 12.2 (19-70) years. Patients underwent T-lymphocyte phenotyping and lymphoproliferation assay at diagnosis, and experiments related to thymic function and interferon (IFN)-γ release by natural killer (NK) cell were performed. Mean follow-up was 6.9 ± 6.7 (0.14-24.3) years. Infectious, autoimmune, and neoplastic events were recorded, as were outcomes of interleukin 2 therapy.In all, 25 patients had opportunistic infections (12 with human papillomavirus infection), 14 had autoimmune symptoms, 5 had malignancies, and 8 had mild or no symptoms. At the time of diagnosis, the mean cell counts were as follows: mean CD4 cell count: 127/mm (range, 4-294); mean CD8: 236/mm (range, 1-1293); mean CD19: 113/mm (range, 3-547); and mean NK cell count: 122/mm (range, 5-416). Most patients had deficiency in CD8, CD19, and/or NK cells. Cytotoxic function of NK cells was normal, and patients with infections had a significantly lower NK cell count than those without (p = 0.01). Patients with autoimmune manifestations had increased CD8 T-cell count. Proliferation of thymic precursors, as assessed by T-cell rearrangement excision circles, was increased. Six patients died (15%). CD4 T-cell count <150/mm and NK cell count <100/mm were predictors of death.In conclusion, ICL is a heterogeneous disorder often associated with deficiencies in CD8, CD19, and/or NK cells. Long-term prognosis may be related to initial CD4 and NK cell deficiency.

Idiopathic CD4 Lymphocytopenia: Spectrum of opportunistic infections, malignancies, and autoimmune diseases

Idiopathic CD4 lymphocytopenia (ICL) was first defined in 1992 by the US Centers for Disease Control and Prevention (CDC) as the repeated presence of a CD4+ T lymphocyte count of fewer than 300 cells per cubic millimeter or of less than 20% of total T cells with no evidence of human immunodeficiency virus (HIV) infection and no condition that might cause depressed CD4 counts. Most of our knowledge about ICL comes from scattered case reports. The aim of this study was to collect comprehensive data from the previously published cases to understand the characteristics of this rare condition. We searched the PubMed database and Science Direct for case reports since 1989 for Idiopathic CD4 lymphocytopenia cases. We found 258 cases diagnosed with ICL in 143 published papers. We collected data about age, sex, pathogens, site of infections, CD4 count, CD8 count, CD4:CD8 ratio, presence of HIV risk factors, malignancies, autoimmune diseases and whether the patients survived or died. The mean age at diagnosis of first opportunistic infection (or ICL if no opportunistic infection reported) was 40.7 ± 19.2 years (standard deviation), with a range of 1 to 85. One-sixty (62%) patients were males, 91 (35.2%) were females, and 7 (2.7%) patients were not identified whether males or females. Risk factors for HIV were documented in 36 (13.9%) patients. The mean initial CD4 count was 142.6 ± 103.9/mm³ (standard deviation). The mean initial CD8 count was 295 ± 273.6/mm³ (standard deviation). The mean initial CD4:CD8 ratio was 0.6 ± 0.7 (standard deviation). The mean lowest CD4 count was 115.4 ± 87.1/mm³ (standard deviation). The majority of patients 226 (87.6%) had at least one infection. Cryptococcal infections were the most prevalent infections in ICL patients (26.6%), followed by mycobacterial infections (17%), candidal infections (16.2%), and VZV infections (13.1%). Malignancies were reported in 47 (18.1%) patients. Autoimmune diseases were reported in 37 (14.2%) patients.

Progressive multifocal leukoencephalopathy and idiopathic CD4 lymphocytopenia

Idiopathic CD4 lymphocytopenia (ICL) is a syndrome described in patients with low counts of CD4 cells and no other causes for immunosuppression. A few cases of progressive multifocal leukoencephalopathy (PML) have been described in association with this entity. There is no effective treatment for any of them, and the clinical course and outcome are unpredictable. We report on a case of ICL with PML and review the literature, trying to identify the clinical features and the prognosis clues associated to these entities together. A 72-year-old man presented with acute onset gait instability that progressed to a severe cerebellar syndrome with cognitive decline. A cranial MRI showed findings consistent with PML, this diagnosis being confirmed by CSF analyses. Absolute number of CD4+ was 242 cells/μL. An extensive work-up including HIV tests was negative. Ten cases of PML and ICL have previously been reported. Factors contributing to the different outcomes are unknown. Although an effective treatment does not exist for PML, it has been recently demonstrated in vitro that several 5HT2A-receptor antagonists block the JC virus infection. Our patient greatly improved and remains stable 34 months after onset; we describe the potential role of mirtazapine in the treatment of PML.

JC virus infection of the brain

Since its initial description, there have been significant changes in the epidemiology, pathogenesis, and clinical and imaging manifestations of JCV infection of brain. The most common clinical manifestation is PML. Other recently described CNS manifestations are JCE, JCVGCN, and JCM. Although AIDS is the most common predisposing factor for JCV reactivation, there is increasing incidence of brain manifestations of JCV reactivation in non-HIV settings, including different rheumatologic, hematologic, and oncologic conditions; monoclonal antibody therapy; transplant recipients; primary immunodeficiency syndromes; and even in patients without any recognizable immune deficiency. IRIS may develop secondary to restoration of immunity in HIV-positive patients with PML receiving antiretroviral therapy. This is of profound clinical significance and needs to be diagnosed promptly. Imaging plays a crucial role in the diagnosis of the disease, monitoring of treatment response, identifying disease progression, and predicting prognosis. In this article, current understanding of the epidemiology, pathogenesis, clinical presentations, and all aspects of imaging of JCV infection of the brain have been comprehensively reviewed.

Progressive multifocal leukoencephalopathy showing extensive spinal cord involvement in a patient with lymphocytopenia

A 64-year-old Japanese man who was diagnosed as having cerebral infarcts at an early clinical stage was found to have progressive multifocal leukoencephalopathy (PML). A decrease of leukocytes and lymphocytes had been detected in the previous year. During a total clinical course of 11 months, he showed marked depletion of lymphocytes ranging from 264/microL to 459/microL. Autopsy disclosed no underlying diseases such as malignancies or tuberculosis. Extensive PML lesions were seen in the cerebral white matter. Small perivascular cuffs comprising many CD8+ T lymphocytes and a few CD4+ T cells were scattered in the PML lesions. CD20+ B cells were rarely evident. The subsets of the infiltrating lymphocytes differed from those of primary or spontaneous PML. Similar extensive PML lesions were observed not only in the cerebellum and brainstem but also in the spinal cord. All 26 segments of the spinal cord, especially the cervical, lumbar and sacral cord, showed extensive lesions involving the lateral and anterior columns. To our knowledge, only three cases of PML with such extensive spinal cord lesions have been reported previously. These three cases, and the present one, may represent a group of PML that shows extensive lesions in the spinal cord as well as the cerebrum, cerebellum and brainstem. The underlying disease in the present case was unclear. Because lymphocytopenia is not observed in primary or spontaneous PML, and the immunohistochemical findings of the infiltrating lymphocytes in the present case are different from primary or spontaneous PML, the decrease in his total blood lymphocytes may have played a significant role in his immunosuppressed condition as the underlying disease.

Progressive multifocal leukoencephalopathy and CD4+ T-lymphocytopenia in a patient with Sjögren syndrome

We report progressive multifocal leukoencephalopathy (PML) and CD4+ T-lymphocytopenia in a 71-year-old man with Sjögren syndrome (SjS). The patient was admitted to our hospital because of progressive dementia and gait disturbance. T2-weighted MR images showed high-intensity lesions in his left frontal white matter thalamus, cerebellum and brainstem. A pathological diagnosis of PML was made by brain biopsy. SjS is frequently accompanied with immunological complications; however, there are few reports on PML in patients with SjS. Recently, isolated CD4+ T-lymphocytopenia is reported to be one of the based immunological conditions associated with the development of PML. In the present case, CD4+ T-lymphocytopenia was also observed on admission, which is also associated with SjS.

Progressive multifocal leukoencephalopathy in a patient with common variable immunodeficiency and abnormal CD8+ T-cell subset distribution

BACKGROUND

Patients with primary hypogammaglobulinemia have been reported to have encephalopathy, but progressive multifocal leukoencephalopathy (PML) due to JC virus reactivation is a rare cause.

OBJECTIVE

To provide the clinical details and case discussion of a patient diagnosed as having common variable immunodeficiency (CVID) who has progressive neurodegenerative symptoms and was found to have PML and an abnormal CD8+ T-cell subset distribution.

METHODS

A detailed case report providing the patient's immunodeficiency history, diagnostic evaluation, and medical management and a review of related literature.

RESULTS

Before his neurodegenerative illness, the patient was found to have hypogammaglobulinemia, poor specific antibody responses, low circulating B-cell levels, and abnormal delayed-type hypersensitivity responses; there was no Bruton tyrosine kinase (BTK) mutation. The PML was diagnosed using brain biopsy and was confirmed using a DNA probe specific for JC virus. Peripheral blood flow cytometry at the time of PML diagnosis revealed an accumulation of naive CD8+ T cells (CD3+CD8+CD45RA+) and a deficiency of memory CD8+ T-cell subsets (CD3+CD8+CD45RA- or CD3+CD8+CD45RO+). Despite aggressive treatment with interleukin 2, interferon-gamma, and intravenous cidofovir, the patient died.

CONCLUSIONS

JC virus infection should be considered in the differential diagnosis of the patient with CVID and signs and symptoms of encephalopathy. The role of this patient's abnormal CD8' T-cell subset distribution in the development or control of this rare infection is worthy of consideration and has encouraged us to enumerate naive and memory CD4+ and CD8+ T-cell subsets in patients diagnosed as having CVID, even in the absence of neurodegenerative symptoms.

Long-term remission in progressive multifocal leukoencephalopathy caused by idiopathic CD4+ T lymphocytopenia: a case report

Progressive multifocal leukoencephalopathy is caused by JC virus, an opportunistic infection of the central nervous system. Antiretroviral treatment for progressive multifocal leukoencephalopathy in human immunodeficiency virus-infected patients is beneficial, but few data exist for patients who are not infected with human immunodeficiency virus. Idiopathic CD4+ T lymphocytopenia excludes human immunodeficiency virus infection. We describe a patient with progressive multifocal leukoencephalopathy with underlying idiopathic CD4+ T lymphocytopenia in whom functional recovery occurred without antiviral therapy.

Progressive multifocal leukoencephalopathy and idiopathic CD4+lymphocytopenia: a case report and review of reported cases

Progressive multifocal leukoencephalopathy (PML) is a well recognized demyelinating neurological disorder caused by JC virus. Idiopathic CD4(+) lymphocytopenia (ICL) is a syndrome first described by the Centers for Disease Control and Prevention as a CD4(+) count <300 cells/mm(3) or a CD4(+) count that is <20% of the total T cell count on 2 occasions, with no evidence of human immunodeficiency virus (HIV) infection on testing, and absence of any defined immunodeficiency or therapy that depresses the levels of CD4(+) T cells. To the best of our knowledge, this is the third reported case of PML and ICL, and also the first reported case of the use of cidofovir to treat PML in a patient not infected with human immunodeficiency virus.