Contributions
Abstract: P297
Type: Poster
Abstract Category: Clinical aspects of MS - 1 Diagnosis and differential diagnosis
The complexity of multiple sclerosis (MS) requires different biomarkers in order to evaluate the disease in its various aspects. The common laboratory tests in MS are performed using cerebrospinal fluid (CSF), but the need of lumbar puncture makes CSF tests impractical to monitor disease activity and response to treatment. In our search for the non-invasive diagnostic methods we hypothesized that immunoglobulin (Ig) free light chains (FLC) analysis in saliva may help to detect the immune-pathological changes in MS. This assumption relied on the reports indicating the changes in mucosal immunity in MS patients, and on a growing body of evidence of a diagnostic role of FLC in MS.
A new technique based on Western blot analysis was developed to study k and λ FLC monomers (M) and dimers (D) in the saliva. Normal saliva showed high proportion of dimeric FLC as compared to that in the serum. This finding might be explained by structural peculiarities of Ig in saliva: in contrast to most serum Ig, saliva IgA2 molecules incorporate the dimeric (not monomeric) light chains that may require production of larger amounts of dimeric light chains by the B cells synthesizing IgA2.
FLC M-D patterns in the saliva of MS patients were compared to those in healthy subjects. The intensity of the immunoreactive FLC was measured, and the FLC indices accounting for the total FLC level and for M/D ratios (k M/D index and λ M/D index) were computed. Most patients with active MS showed abnormally high FLC levels, or/and a high proportion of monomeric FLC. The reasons for such pathological FLC changes in active MS are not clear, but they might be due to peripheral B lymphocytes penetrating oral mucosa and producing larger amounts of monomeric FLC. Statistical analysis of these indices showed significant differences not only between active MS patients (n=27) and healthy subjects (n=28), but also between active MS patients (n=27) and those in remission (n=58).
The cut-off values were established to distinguish a healthy state from the pathological conditions in MS: total FLC level index = 17, k M/D index = 4.0, λ M/D index = 2.4. Most MS patients with active disease showed FLC indices above these cut-off values. The specificity and sensitivity of our technique for diagnosing the active MS was determined as 80% and 89%, respectively. The developed procedure may serve as a new non-invasive complimentary tool to evaluate the MS disease state and response to treatment.
Disclosure:
Support: The study was supported by the National Multiple Sclerosis Society (USA), grant PP 1512-07139.
Disclosure of conflict of interests:
Shlomo Flechter: no conflict of interests
Batia Kaplan:no conflict of interests
Sizilia Golderman: no conflict of interests
Esther Ganelin-Cohen: no conflict of interests
Alla Miniovitch: no conflict of interests
Eitan Korf: no conflict of interests
Ilan Ben-Zvi: no conflict of interests
Avi Livneh: no conflict of interests
Abstract: P297
Type: Poster
Abstract Category: Clinical aspects of MS - 1 Diagnosis and differential diagnosis
The complexity of multiple sclerosis (MS) requires different biomarkers in order to evaluate the disease in its various aspects. The common laboratory tests in MS are performed using cerebrospinal fluid (CSF), but the need of lumbar puncture makes CSF tests impractical to monitor disease activity and response to treatment. In our search for the non-invasive diagnostic methods we hypothesized that immunoglobulin (Ig) free light chains (FLC) analysis in saliva may help to detect the immune-pathological changes in MS. This assumption relied on the reports indicating the changes in mucosal immunity in MS patients, and on a growing body of evidence of a diagnostic role of FLC in MS.
A new technique based on Western blot analysis was developed to study k and λ FLC monomers (M) and dimers (D) in the saliva. Normal saliva showed high proportion of dimeric FLC as compared to that in the serum. This finding might be explained by structural peculiarities of Ig in saliva: in contrast to most serum Ig, saliva IgA2 molecules incorporate the dimeric (not monomeric) light chains that may require production of larger amounts of dimeric light chains by the B cells synthesizing IgA2.
FLC M-D patterns in the saliva of MS patients were compared to those in healthy subjects. The intensity of the immunoreactive FLC was measured, and the FLC indices accounting for the total FLC level and for M/D ratios (k M/D index and λ M/D index) were computed. Most patients with active MS showed abnormally high FLC levels, or/and a high proportion of monomeric FLC. The reasons for such pathological FLC changes in active MS are not clear, but they might be due to peripheral B lymphocytes penetrating oral mucosa and producing larger amounts of monomeric FLC. Statistical analysis of these indices showed significant differences not only between active MS patients (n=27) and healthy subjects (n=28), but also between active MS patients (n=27) and those in remission (n=58).
The cut-off values were established to distinguish a healthy state from the pathological conditions in MS: total FLC level index = 17, k M/D index = 4.0, λ M/D index = 2.4. Most MS patients with active disease showed FLC indices above these cut-off values. The specificity and sensitivity of our technique for diagnosing the active MS was determined as 80% and 89%, respectively. The developed procedure may serve as a new non-invasive complimentary tool to evaluate the MS disease state and response to treatment.
Disclosure:
Support: The study was supported by the National Multiple Sclerosis Society (USA), grant PP 1512-07139.
Disclosure of conflict of interests:
Shlomo Flechter: no conflict of interests
Batia Kaplan:no conflict of interests
Sizilia Golderman: no conflict of interests
Esther Ganelin-Cohen: no conflict of interests
Alla Miniovitch: no conflict of interests
Eitan Korf: no conflict of interests
Ilan Ben-Zvi: no conflict of interests
Avi Livneh: no conflict of interests