[Actual issues of serum aquaporin-4 autoantibodies evaluation in the diagnostics of neuromyelitis optica spectrum disorders]. / Aktual'nye voprosy diagnostiki zabolevanii spektra optikoneiromielita pri opredelenii antitel k akvaporinu-4 v syvorotke krovi.

OBJECTIVE: To analyze the usage and timeliness of aquaporin-4 antibodies (AQP4-IgG) serology test in the diagnostics of neuromyelitis optica spectrum disorders (NMOSD) in routine clinical practice. MATERIAL AND METHODS: 27 patients with NMOSD were included in the study. All patients had a positive serum test for AQP4-IgG. A retrospective study of neurological manisfestations of attacks, timing and results of serology for AQP4-IgG was performed. The results were analyzed taking into account two types of attacks identified: a) HS (with highly specific manifestations for NMOSD), which are considered as indications for conducting the AQP4-IgG test and b) NS (with non-specific manifestations for NMOSD). RESULTS AND CONCLUSION: A comparison of the time from HS attack to the AQP4-IgG test administration (T1, years), from HS attack to NMOSD diagnosis (T2, years) was undertaken as well as the number of attacks during these periods (N1, N2) were counted in three groups of patients. Group 1 - with the first HS attack before or in 2008 (n=6), group 2 - from 2009 to 2013 (n=12), group 3 - from 2014 to 2018 (n=9) accordingly. A statistically significant decrease in T1, T2, N1, N2 was found in successive time intervals of 5 years (p<0.05). In 8 of 27 (28.6%) patients the first attack of NMOSD was presented with non-specific symptoms (NS attack). In 7 patients (77.8%) of 9 misdiagnosed as multiple sclerosis (MS) an increase in attack frequency was found while on disease modifying therapies (DMTs) and increase in attack severity was found in 8 (88.9%). In all 9 cases the diagnosis was revised to NMOSD after AQP4-IgG test was performed with positive result. The time interval from disease course worsening while on DMTs until the test was 7 [4; 37] months, and the number of relapses - 2 [0; 3]. In 4 of 27 patients with suspected NMOSD, the repeated AQP4-IgG test only was positive for increased antibodies titer. The time interval between first test negative and retest administered was 20 [6.1; 47.8] months. In 3 of 4 patients (75%) one or more attacks occurred during this time period. In 4 patients the presence of AQP4-IgG in the first analysis was not followed by the diagnosis of NMOSD. In recent years, apropos AQP4-IgG test administration improved, but the problem remains with the timeliness for retest with first result negative. It is advisable to expand the indications for its use. The timeliness for serum AQP4-IgG retest in cases of unexplained deterioration in the course of proposed MS on DMTs and the lack of awareness of the test diagnostic value are still relevant.

[Comorbidity of neuromyelitis optica spectrum disorder and systemic lupus erythematosus]. / Komorbidnost' zabolevaniya spektra optikoneiromielita i sistemnoi krasnoi volchanki.

The comorbidity of neuromyelitis optica spectrum disorder (NMOSD) and systemic lupus erythematosus (SLE) is a poorly studied problem. The issues of the pathogenetic relationship between these diseases, timely diagnosis of their co-existence in one patient, disease course and therapeutic approaches are the most relevant. The authors summarize current views on the state of the problem and analyze three clinical cases of NMOSD and SLE comorbidity including the diagnostic issues and therapeutic approaches.

[Diagnostic value of immunoglobulin free light chains at the debut of multiple sclerosis]. / Rol' opredeleniia svobodnykh legkikh tsepei immunoglobulinov v diagnostike debiuta rasseiannogo skleroza.

AIM: To evaluate the diagnostic value of determination of free immunoglobulin light chains (IgG) in the debut of multiple sclerosis (MS). MATERIAL AND METHODS: Data from 226 patients, including 111 patients with clinically isolated syndrome with conversion to multiple sclerosis within the first 2 years of the disease (group 1), 49 patients with clinically isolated syndrome who did not develop multiple sclerosis within the first 2 years of the disease (group 2), 20 patients with other inflammatory diseases of the central nervous system (group 3) were analyzed. The control group consisted of 46 patients with non-inflammatory diseases of the central nervous system. The clonality of immunoglobulins in the CSF, concentration of kappa and lambda free light chains and their ratio were studied. RESULTS: Concentrations of free light chains were significantly higher in the first group in comparison with group 2 and the control group, but didn't differ from group 3. In group 3, concentrations of free light chains were significantly higher compared to group 2 and controls. In oligoclonal-positive patients with clinically isolated syndrome (groups 1 and 2), concentrations of kappa and lambda free light chains were significantly higher than in oligoclonal-negative patients. The production of free light chains in patients from the first group was considerably higher than in group 2 regardless of the oligoclonal status. The concentration of kappa chains and quotient of kappa free light chains in the CSF had the best diagnostic characteristics. Their use, along with the evaluation of IgG clonality, reduced the risk of false-negative results by 50%. Regardless of other factors, elevated concentrations of kappa chains increase the likelihood of MS diagnosis by 9.718 times. CONCLUSION: The use of free light chains as a laboratory marker can increase the accuracy of MS diagnosis. These markers can help indirectly assess the risk of transformation of a clinically isolated syndrome into definite multiple sclerosis within the first 2 years of disease.

[The association of intrathecal production of immunoglobulin free light chains and progression of multiple sclerosis]. / Sviaz' intratekal'noi produktsii svobodnykh legkikh tsepei immunoglobulinov s progressirovaniem rasseiannogo skleroza.

AIM: To assess an impact of immunoglobulin free light chains (FLC) on short-term and long-term prognosis of clinical and radiological activity and progression of disability in multiple sclerosis (MS). MATERIAL AND METHODS: A sample of 381 patients with definite MS was divided into 2 groups. In group 1, lumbar puncture was performed at the time of clinically isolated syndrome, and patients were prospectively followed up to 2 years (short-term prognosis group, n=97). In group 2, MS was diagnosed immediately after lumbar puncture, and retrospective analysis of the disease course with the duration not less than 5 years was performed (long-term prognosis group, n=284). The Expanded Disability Status Scale (EDSS) and the Multiple Sclerosis Severity Score (MSSS) were used to assess patient's status. Concentrations of kappa and lambda FLC in the CSF (K-FLCCSF, L-FLCCSF) and serum (K-FLCSERUM, L-FLCSERUM) as well as quotients of concentrations (Q-K and Q-L) were determined. Patients were stratified into subgroups with high and low concentrations of K-FLC and L-FLC using cut-offs from our previous studies: K-FLCCSF=0.595 mcg/l and L-FLCCSF=0.127 mcg/l. RESULTS: In group 1, significant correlations were found only between EDSS score and concentrations of K-FLCCSF (r=0.377, p=0.00019) and Q-K (r=0.366, p=0.0012). FLC concentrations did not correlate with the number of relapses and new T2 lesions. The age and EDSS score at the disease onset didn't differ between patients with high and low K-FLC and L-FLC (K-FLCCSF: р=0.2658; L-FLCCSF: р=0.5502). A significant decrease of EDSS score after the disease onset was observed in all groups except for patients with high concentrations of K-FLCCSF (p=0.1844), so the EDSS score after 2 years was significantly higher in this subgroup of patients (p=0.0006). In group 2, significant correlations of K-FLC with EDSS score (r=0.181, p=0.002) and MSSS score (r=0.121, р=0.044) for long-term prognosis (median (IQR) = 8 (6-13) years) were found. No correlations of FLC concentrations with the number of relapses during the first 5 years were found. Survival analysis showed that high concentrations of K-FLCCSF were associated with the high risk of progression to EDSS 6 (HR=2.055, p=0.026) but not with EDSS 4 (HR=2.388, p=0.08). CONCLUSION: Concentrations of kappa FLC can help to define the prognosis of MS early at the disease course. Although low concentrations of FLC do not exclude a severe disease phenotype, patients with high K-FLCCSF concentrations are at greater risk for faster MS progression, probably, due to impaired reparation of neural tissue. Measurement of FLC concentrations can be used to determine a therapeutic tactics in patients with MS.

[Current concepts on intrathecal humoral immune response and diagnostic importance of oligoclonal immunoglobulins in multiple sclerosis]. / Sovremennye predstavleniya ob intratekal'nom gumoral'nom immunnom otvete i diagnosticheskoe znachenie vyyavleniya oligoklonal'nykh immunoglobulinov pri rasseyannom skleroze.

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system of probable autoimmune origin. In this review of literature, the authors present a constantly broadening list of potential antigens, including myelin and non-myelin structures, that cause the autoimmune reaction. Determination of antibodies to any antigen has not sufficient specificity and sensitivity for the use in routine laboratory practice. Oligoclonal immunoglobulins determined with isoelectric focusing (IEF) technique are currently considered as the main immunological MS markers. The sensitivity and specificity of IEF are 90 and 86%, respectively. The authors have considered the additional markers such as oligoclonal IgM and MRZ-response.

[The methods of detection of binding and neutralizing antibodies to preparations of interferon-beta].

The human recombinant ß-interferon is most frequently applied for treatment of remittent recurrent form of multiple sclerosis using pharmaceuticals. The clinical response to applied therapy is absent in some of patients that can be conditioned by development of antibodies too preparations. Depending on possibility of blocking binding of human recombinant ß-interferon with its receptor, all antibodies are divided on binding and neutralizing ones. The purpose of study is to investigate analytical and clinical diagnostic parameters of tests using for detection of different types of antibodies synthesized against human recombinant ß-interferon. The study sampling consisted of 33 patients with remittent recurrent form of multiple sclerosis receiving therapy with human recombinant ß-interferon and also of 40 donors and 15 patients with multiple sclerosis without therapy with human recombinant ß-interferon. The concentration of binding antibodies was measured by enzyme-linked immunosorbent assay. Also immune blotting assay was applied. The titer of neutralizing antibodies was determined using cell line HL-116 sensitive to human recombinant ß-interferon. The binding and neutralizing antibodies were not detected in donors and patients without human recombinant ß-interferon therapy. The prevalence of binding antibodies to human recombinant ß-interferon amounted to 57.6% when analysis of samples using immune blotting assay was used and 60.6% when commercial testing system was applied. The statistical analysis of results demonstrated high convergence and correlation of values of concentrations of binding antibodies obtained using immune blotting assay and enzyme-linked immunosorbent assay (r=0.9159, p<0.0001). The clinically significant titers of neutralizing antibodies were detected in 21.21°% of patients. All patients with clinically significant titer of neutralizing antibodies were positive in relation to binding antibodies measured by immune blotting assay and enzyme-linked immunosorbent assay. The high correlation between values of titers of neutralizing antibodies and concentration of binding antibodies measured by immune blotting assay (r=0.7909, p=0.0055). The application in clinical practice of data concerning presence of binding and neutralizing antibodies to human recombinant ß-interferon can input into optimization of therapy with expensive biologic preparations in patients with multiple sclerosis and other autoimmune diseases.