Author Of 1 Presentation
P0244 - A simple two-step test based on CSF flow cytometry helps to discriminate MS from other inflammatory and non-inflammatory neurologic disorders (ID 1943)
Abstract
Background
Several studies have shown that relative proportions of B-lineage cells are increased in CSF of patients with MS as compared to other inflammatory (OIND) and non-inflammatory (NIND) neurologic disorders. We hypothesized that the relative proportion of CD19+ and plasma (CD19+138+) cells in CSF, as assessed with commercially available flow cytometry, could be useful for improving the specificity of MS diagnostics.
Objectives
1. To determine whether a combination of elevated CD19+ cells and plasma (CD19+138+) cells in CSF (‘CD19/Plasma Cell Test’) allows for accurate differentiation of MS from OIND (e.g. MOG Ab disorder, neurosarcoidosis, Susac syndrome) and between MS and NIND (e.g. stoke, malignancies, conversion disorder). 2. To compare the sensitivity and specificity of CD19/Plasma Cell Test to that of oligoclonal bands (OCB) in CSF.
Methods
We retrospectively reviewed the charts of consecutive patients evaluated at NYU Langone Medical Center between 1/2013 - 3/2020 for whom lymphocyte subtyping in CSF was available. We defined ‘elevated CD19 count’ as >1% of total lymphocyte count in CSF and ‘elevated plasma cell count’ as >0.1% of total lymphocyte count in CSF. We calculated proportions of patients with elevated CD19 and, within this subset, of patients with elevated plasma cell counts for MS, OIND, and NIND. We calculated the sensitivity and specificity of the CD19/Plasma Cell Test for discriminating MS from OIND and from NIND.
Results
The cohort was comprised of 69 patients with MS (age at LP: 39.1 ±11.7 years; 64% female, 65% white), 25 with OIND (age - 45.3±13.7; 56% female; 48% white), and 43 with NIND (age - 48.5 ±14.8; 63% female; 70% white). OCB (2 or more) were present in 51/67 MS patients (76%), 10/13 IND (77%) and 0/38 NIND (0%). Thus, OCB had sensitivity 76% for MS, and specificity of 56% for MS when compared to OIND, and 100% when compared to NIND. Elevated CD19 count was found in 45/69 MS patients (65%), 10/25 OIND (40%), and 8/43 of NIND (18%). Of the patients with elevated CD19 count (N=63), 27 MS patients, 3 OIND and 0 NIND patients had an elevated plasma cell count. Thus, a two step-test that sequentially assesses for elevated CD19 count and elevated plasma cell count, has sensitivity of 39% for MS, specificity of 88% for discriminated MS from OIND, and 100% for discriminating MS from NIND.
Conclusions
OCB have high sensitivity for MS, but lack specificity for discriminating MS from OIND. A simple, two-step CD19/Plasma Cell Test, based on widely available flow cytometry assay, was inferior to OCB with regard to sensitivity for MS (39% v. 76%), but superior with regard to specificity (88% v 56%) for discriminating MS from OIND. Both tests had excellent specificity for differentiating MS from NIND.