Contributions
Abstract: P860
Type: Poster Sessions
Abstract Category: Pathology and pathogenesis of MS - Biomarkers
Background: The detection of oligoclonal bands (OCB) using isoelectrofocusing (IEF) is the current gold standard for the evaluation of intrathecal IgG synthesis in Multiple Sclerosis (MS) patients. However, some studies suggest that the presence of cerebrospinal fluid (CSF) IgG free light kappa chains may have a higher diagnostic sensitivity, in particular in patients with Clinically Isolated Syndrome (CIS) and in OCB negative (OCB-) MS patients.
Objective: Aim was to determine the role of kappa and lambda indices (CSF/serum free light kappa or lambda chain ratio divided by CSF/serum albumin ratio) in predicting a MS diagnosis in a group of OCB- patients who underwent a spinal tap because of suspected MS.
Methods: CSF and serum free light kappa and lambda chains were tested on samples stored at -80°C after collection, using the Freelite Kappa/Lambda Free (serum) and Freelite Kappa/Lambda Free Mx (CSF) assay (The Binding Site Group, Birmingham, UK). Patients' clinical records were revised and patients without a final diagnosis were excluded.
Results: We included 392 OCB- patients in the analysis (253F, 138M, mean age 43 +/- 14 years). The final diagnosis was MS in 89 patients (22.7%), other demyelinating diseases (including CIS) in 77 (19.6%), vascular disorders in 63 (16.1%), other inflammatory disorders in 42 (10.7%), infectious diseases in 25 (6.4%) and miscellaneous conditions in the remaining 96 (24.5%).The best kappa index cut-off value for the prediction of MS was 5.8 and high values were present in 21/89 (24%) of OCB- MS patients, as opposed to 20/303 (7%) of non-MS patients (p< 0.001), with a specificity of 93.4%, a sensitivity of 23.6 and an area under the curve (AUC) of 0.59. Furthermore, they increased the odds of a MS diagnosis by more than four-fold (OR:4.4; 95%CI: 2.2-8.5).Lambda index values greater than 2.7 (Youden Index), were present in a low proportion of MS patients (8.9 versus 3.6% in non-MS patients, p=0.039) and had a low AUC (0.53).In a control group of 54 OCB+ MS patients, high kappa index values were present in 53/54 (98.2%) patients as opposed to elevated lambda index levels, present only in 22/54 (40.7%) patients.
Conclusion: Kappa index values greater than 5.8 were present in 24% of OCB- MS patients, suggesting that they could be useful in clinical practice in the identification of OCB- patients with a high risk of a MS diagnosis. The determination of the lambda index does not appear useful in this context.
Disclosure: The study received an unconditional support by Binding Site (Birmingham, UK) through the supply of the necessary Freelite kits.Ferraro D has nothing to disclose in relation to the study. Trovati A has nothing to disclose in relation to the study.Bedin R has nothing to disclose in relation to the study.Natali P has nothing to disclose in relation to the study.Franciotta D has nothing to disclose in relation to the study. Santangelo M has nothing to disclose in relation to the study.Camera V has nothing to disclose in relation to the study. Vitetta F has nothing to disclose in relation to the study.Bagnoli S has nothing to disclose in relation to the study.Varani M has nothing to disclose in relation to the study. Trenti T has nothing to disclose in relation to the study.Nichelli PF has nothing to disclose in relation to the study.Sola P has nothing to disclose in relation to the study.
Abstract: P860
Type: Poster Sessions
Abstract Category: Pathology and pathogenesis of MS - Biomarkers
Background: The detection of oligoclonal bands (OCB) using isoelectrofocusing (IEF) is the current gold standard for the evaluation of intrathecal IgG synthesis in Multiple Sclerosis (MS) patients. However, some studies suggest that the presence of cerebrospinal fluid (CSF) IgG free light kappa chains may have a higher diagnostic sensitivity, in particular in patients with Clinically Isolated Syndrome (CIS) and in OCB negative (OCB-) MS patients.
Objective: Aim was to determine the role of kappa and lambda indices (CSF/serum free light kappa or lambda chain ratio divided by CSF/serum albumin ratio) in predicting a MS diagnosis in a group of OCB- patients who underwent a spinal tap because of suspected MS.
Methods: CSF and serum free light kappa and lambda chains were tested on samples stored at -80°C after collection, using the Freelite Kappa/Lambda Free (serum) and Freelite Kappa/Lambda Free Mx (CSF) assay (The Binding Site Group, Birmingham, UK). Patients' clinical records were revised and patients without a final diagnosis were excluded.
Results: We included 392 OCB- patients in the analysis (253F, 138M, mean age 43 +/- 14 years). The final diagnosis was MS in 89 patients (22.7%), other demyelinating diseases (including CIS) in 77 (19.6%), vascular disorders in 63 (16.1%), other inflammatory disorders in 42 (10.7%), infectious diseases in 25 (6.4%) and miscellaneous conditions in the remaining 96 (24.5%).The best kappa index cut-off value for the prediction of MS was 5.8 and high values were present in 21/89 (24%) of OCB- MS patients, as opposed to 20/303 (7%) of non-MS patients (p< 0.001), with a specificity of 93.4%, a sensitivity of 23.6 and an area under the curve (AUC) of 0.59. Furthermore, they increased the odds of a MS diagnosis by more than four-fold (OR:4.4; 95%CI: 2.2-8.5).Lambda index values greater than 2.7 (Youden Index), were present in a low proportion of MS patients (8.9 versus 3.6% in non-MS patients, p=0.039) and had a low AUC (0.53).In a control group of 54 OCB+ MS patients, high kappa index values were present in 53/54 (98.2%) patients as opposed to elevated lambda index levels, present only in 22/54 (40.7%) patients.
Conclusion: Kappa index values greater than 5.8 were present in 24% of OCB- MS patients, suggesting that they could be useful in clinical practice in the identification of OCB- patients with a high risk of a MS diagnosis. The determination of the lambda index does not appear useful in this context.
Disclosure: The study received an unconditional support by Binding Site (Birmingham, UK) through the supply of the necessary Freelite kits.Ferraro D has nothing to disclose in relation to the study. Trovati A has nothing to disclose in relation to the study.Bedin R has nothing to disclose in relation to the study.Natali P has nothing to disclose in relation to the study.Franciotta D has nothing to disclose in relation to the study. Santangelo M has nothing to disclose in relation to the study.Camera V has nothing to disclose in relation to the study. Vitetta F has nothing to disclose in relation to the study.Bagnoli S has nothing to disclose in relation to the study.Varani M has nothing to disclose in relation to the study. Trenti T has nothing to disclose in relation to the study.Nichelli PF has nothing to disclose in relation to the study.Sola P has nothing to disclose in relation to the study.