Sara Nordström1,2, Bengt Andersson3,4, Clas Malmeström1,2,3,4. 1. Department of Neurology, University of Gothenburg, Gothenburg, Sweden. 2. Institute of neuroscience and physiology, University of Gothenburg, Gothenburg, Sweden. 3. Laboratory for Clinical Immunology, University of Gothenburg, Gothenburg, Sweden. 4. Sahlgrenska university hospital, University of Gothenburg, Gothenburg, Sweden.
Abstract
OBJECTIVE: Neurosarcoidosis affects 5%-10% of patients with sarcoidosis. CD4+ /CD8+ ratio in bronchoalveolar lavage is included in diagnostic routine for pulmonary sarcoidosis. Previously, it has been suggested that a cerebrospinal fluid CD4+ /CD8+ ratio ≥5 can be an aid in diagnosing neurosarcoidosis. MATERIALS AND METHODS: This study included 66 cases where neurosarcoidosis was a differential diagnosis and hence subjected to the analysis of CSF CD4+ /CD8+ ratio by flow cytometry. RESULTS: Eleven cases of neurosarcoidosis, had a significantly higher median CSF CD4+ /CD8+ ratio than the other group, P = .024. The median CSF CD4+ /CD8+ ratio was 4.2, hence not reaching the suggested level of ≥5 for diagnosing neurosarcoidosis. When combined, the elevated CSF CD4+ /CD8+ ratio ≥5 and an elevated CSF lymphocyte count (>3 lymphocytes/uL) gave a positive predictive value of 57% and a high negative predictive value of 88%, with a specificity of 95% for neurosarcoidosis. CONCLUSION: The study confirms that increased CSF CD4+ /CD8+ ratio is associated with neurosarcoidosis but cannot alone distinguish the conditions from other neurological diagnoses. However, a ratio below <5 combined with an absence of pleocytosis in CSF yields a negative predictive value (NPV) of 88% suggesting a role for the analysis in differential diagnosing neuroinflammatory conditions.
OBJECTIVE:Neurosarcoidosis affects 5%-10% of patients with sarcoidosis. CD4+ /CD8+ ratio in bronchoalveolar lavage is included in diagnostic routine for pulmonary sarcoidosis. Previously, it has been suggested that a cerebrospinal fluid CD4+ /CD8+ ratio ≥5 can be an aid in diagnosing neurosarcoidosis. MATERIALS AND METHODS: This study included 66 cases where neurosarcoidosis was a differential diagnosis and hence subjected to the analysis of CSF CD4+ /CD8+ ratio by flow cytometry. RESULTS: Eleven cases of neurosarcoidosis, had a significantly higher median CSF CD4+ /CD8+ ratio than the other group, P = .024. The median CSF CD4+ /CD8+ ratio was 4.2, hence not reaching the suggested level of ≥5 for diagnosing neurosarcoidosis. When combined, the elevated CSF CD4+ /CD8+ ratio ≥5 and an elevated CSF lymphocyte count (>3 lymphocytes/uL) gave a positive predictive value of 57% and a high negative predictive value of 88%, with a specificity of 95% for neurosarcoidosis. CONCLUSION: The study confirms that increased CSF CD4+ /CD8+ ratio is associated with neurosarcoidosis but cannot alone distinguish the conditions from other neurological diagnoses. However, a ratio below <5 combined with an absence of pleocytosis in CSF yields a negative predictive value (NPV) of 88% suggesting a role for the analysis in differential diagnosing neuroinflammatory conditions.