Diagnostic delay in progressive multifocal leukoencephalopathy

Area of Science:

• Neurology
• Infectious Diseases
• Immunology

Background:

• Progressive multifocal leukoencephalopathy (PML) is a rare, severe demyelinating disease of the central nervous system.
• PML is caused by the JC virus (JCV) and primarily affects immunocompromised individuals.
• Diagnostic delays can significantly impact patient outcomes and treatment strategies.

Purpose of the Study:

• To investigate the extent and factors associated with diagnostic delay in progressive multifocal leukoencephalopathy (PML).
• To analyze the time from symptom onset to diagnosis in a cohort of PML patients.
• To identify patient subgroups experiencing longer diagnostic delays.

Main Methods:

• Retrospective analysis of 111 patients diagnosed with PML between 1993 and 2015.
• Calculation of the median time from initial symptom to diagnosis.
• Comparison of diagnostic timelines across different patient characteristics and underlying conditions.

Main Results:

• The median diagnostic delay for PML was 74 days (range: 1-1643 days).
• Nearly two-thirds of patients had an alternative diagnosis considered before PML.
• Over three-quarters of patients experienced a diagnostic delay exceeding one month.
• Extended delays were more frequent in patients with possible PML and in HIV-positive individuals with higher CD4+ T-cell counts at symptom onset.

Conclusions:

• Significant diagnostic delays are common in progressive multifocal leukoencephalopathy, regardless of the underlying immunosuppressive condition.
• Prompt diagnosis of PML is crucial for initiating appropriate management, potentially improving survival through immune reconstitution and avoiding unnecessary interventions.