Рассеянный склероз представляет собой аутоиммунное прогрессирующее нейродегенеративное заболевание центральной нервной системы. Повышенный интратекальный синтез иммуноглобулинов, а также появление олигоклональных антител в цереброспинальной жидкости являются основными иммунологическими проявлениями рассеянного склероза. Свободные легкие цепи представляют собой фрагменты иммуноглобулинов различных фракций, синтезирующиеся параллельно олигоклональным антителам и отражающие общую величину синтеза иммуноглобулинов в центральной нервной системе. Поскольку свободные легкие цепи способны пассивно проникать через гематоэнцефалический барьер, используются коэффициенты, которые позволяют нормализовать концентрации свободных легких цепей в цереброспинальной жидкости в зависимости от их сывороточной концентрации и проницаемости гематоэнцефалического барьера. Цель исследования состояла в оценке информативности определения показателей интратекального синтеза свободных легких цепей при рассеянном склерозе. В исследовании принимали участие 151 пациент. Пациенты были разделены на три группы: первая группа (n = 33) – пациенты с клинически изолированным синдромом, который конвертировался в рассеянный склероз, вторая (n = 92) – пациенты с рассеянным склерозом. Третью группу (группу сравнения) составили пациенты с воспалительными и невоспалительными заболеваниями нервной системы (n = 26). У пациентов были определены следующие показатели: клональность иммуноглобулинов в цереброспинальной жидкости, концентрация свободных легких цепей каппа и лямбда в цереброспинальной жидкости, их коэффициенты и индексы, а также отношение концентрации каппа цепей к лямбда в цереброспинальной жидкости. Нами было обнаружено, что в цереброспинальной жидкости у пациентов с рассеянным склерозом преобладает синтез каппа-цепей. Кроме этого, у пациентов с положительным результатом теста на олигоклональные антитела концентрация свободных легких цепей была статистически значимо выше, чем у пациентов с отсутствием интратекального олигоклонального синтеза. Также было показано, что наиболее ценным диагностическим маркером является коэффициент каппа-цепей. Его использование вместе с оценкой клональности синтеза иммуноглобулинов на 42% уменьшало количество ложноотрицательных результатов. Вне зависимости от других факторов повышенные значения коэффициента каппа цепей в 7,7 раз увеличивали вероятность диагноза рассеянного склероза. Также проведенные расчеты показали, что концентрация свободных легких цепей лямбда в цереброспинальной жидкости обратно коррелировала со скоростью конверсии клинически изолированного синдрома в рассеянный склероз. Таким образом, расчет показателей свободных легких цепей позволяет повысить точность диагностики и оценку тяжести течения рассеянного склероза.

Introduction. The clinical picture of Wilson-Konovalov disease (WKD) is characterized by pronounced polymorphism and classical laboratory findings often do not allow to make diagnosis. The most reliable way to confirm the presence of WKD is to identify mutations in the ATP7B gene. Materials and methods. In the course of the research, we developed a method of genetic diagnostics, including realtime PCR to determine a point mutation in combination with fragment analysis to identify deletions and insertions. 20 patients were collected in whom the diagnosis of WKD was made basing on the results of clinical and laboratory criteria of the disease according to the Leipzig scoring system. All patients were genotyped with the developed technique. Anamnestic, clinical, and laboratory data were collected for 12 patients. Results. We detected the following aberrancies in patients from the group 1: heterozygous mutations according to H1069Q (60%), homozygous mutations according to H1069Q (30%), combination of mutations 3627_3630del.4/ H1069Q in heterozygous form (5%), combination of mutations1770insT/H1069Q in heterozygous form (5%). Discussion. Clinical feature of WKD is non-specific, and the combination of liver and nervous system damage typical for WKD, Kayser–Fleischer rings are far from being present in all patients or appear in the later stages of the disease. A considerable amount of false-negative results of WKD laboratory markers indicates the insufficient sensitivity of these research methods. The variability of clinical and laboratory markers of WKD delays the etiology diagnosis and the onset of pathogenetic therapy. Conclusion. The developed method of genetic diagnosis of WKD is recommended for all patients of the Russian population with suspected hepatic, neurological or mixed form of WKD in order to make a timely diagnosis and start treatment.

Diagnosis of Gilbert’s syndrome is based on the detection of homozygous carriage of an additional TA-repeat in the promoter of the UGT1A1 gene, leading to a decrease in the activity of the UGT enzyme. No large studies have been done in the Russian Federation on the prevalence of carriage of Gilbert’s syndrome, as well as the biochemical and molecular profile of such patients. The aim of the study is to evaluate biochemical and molecular genetic parameters in patients with Gilbert’s syndrome in Russia. The study included 124 healthy volunteers (group 1) and 5650 patients with suspected Gilbert’s syndrome (group 2). The number of TA-repeats of the promoter region of the UGT1A1 gene was determined by the method of fragment analysis for all participants. The following biochemical parameters were analyzed for 299 patients from group 2: the level of bilirubin and its fractions, AST, ALT, cholesterol and LDL. In group 1 the prevalence of genotype (TA)6/(TA)6 was 39,52%, (TA)6/(TA)7 - 53,23%, (TA)7/(TA)7 - 7,26%, no rare forms were found. In group 2 the prevalence of genotype (TA)6/(TA)6 was 6,04%, (TA)6/(TA)7 - 20,05%, (TA)7/(TA)7 - 73,7%, rare alleles - 0,2%. Rare alleles included (TA)5/(TA)6, (TA)5/(TA)7, (TA)6/(TA)8 and (TA)7/(TA)8, as well as a new genotype not described in the literature previously - (TA)7/(TA)9. When assessing the level of total bilirubin and its fractions, a difference was revealed between the genotype of Gilbert’s syndrome (TA)7/(TA)7 and the reference genotype (TA)6/(TA)6, and between genotypes (TA)7/(TA)7 and (TA)6/(TA)7. A significant increase in total bilirubin was demonstrated in carriers of a larger number of TA-repeats. There was no significant difference in the concentration of ALT, AST, cholesterol or LDL between different genotypes.The number of TA-repeats of the UGT1A1 gene affects the increase of total bilirubin and its indirect fraction, including the cases of rare allelic variants (TA≤5, TA≥8), but not the activity of ALT and AST and the lipid profile.

Introduction. The basis of autoimmune inflammation in multiple sclerosis (MS) is the polyclonal activation of B lymphocytes in the central nervous system, followed by intrathecal immunoglobulin production, caused by the synthesis of antibodies to measles, rubella, and varicella zoster viruses (MRZ reaction). The study aimed to assess the possibility of using the IgG index, oligoclonal immunoglobulin synthesis, the permeability coefficient of the blood-brain barrier, specific indices of antibodies against measles, rubella, and varicella zoster viruses with the calculation of the MRZ reaction in the diagnosis of MS, neuromyelitis optica, and acute disseminated encephalomyelitis. Materials and methods. The study included 40 patients with the following diagnoses: MS (n = 19), acute disseminated encephalomyelitis (n = 11), and neuromyelitis optica (n = 10). Intrathecal synthesis indicators were measured in all patients in paired samples of cerebrospinal fluid and serum. Study results. In the study group, the MRZ reaction was a specific test for the diagnosis of MS and was not found in neuromyelitis optica or acute disseminated encephalomyelitis. An increase in the IgG synthesis index was observed in only 90.5% of patients with MS, and oligoclonal IgG was detected in only 71.4% of cases. Elevated albumin quotient values are not typical for MS, which characterizes the degree of permeability of the blood-brain barrier. Conclusion. The MRZ reaction is a highly specific laboratory marker for verifying MS. It also enables differential diagnosis of MS and other demyelinating diseases.

Introduction. The emergence of new markers that determine the choice of therapy for metastatic colorectal cancer (CRC) has led to an increase in overall survival. The optimal treatment tactics now take into account both clinical and molecular-genetic characteristics of the tumor.Aim. Investigation of the features of the KRAS, NRAS and BRAF mutations and amplification of the HER2 gene depending on microsatellite instability (MSI) in CRC.Materials and methods. The study included 400 patients with CRC. MSI, BRAF V600E mutation, mutations in the KRAS and NRAS genes was identified to them. MSI was determined by fragment analysis, and mutations in the KRAS, NRAS, BRAF genes by realtime PCR. HER2 amplification was determined in 100 patients with a negative RAS/BRAF. NTRK translocations were determined in all patients with MSI. Data on preoperative levels of CEA and CA19-9 were obtained from 185 patients.Results and discussion. The prevalence of MSI was 6.8%. The prevalence of KRAS, NRAS, BRAF mutations in CRC with MSI was 66.7%, and in CRC with MSS - 52.3%. In patients with MSI, the level of CEA was lower than in MSS (p = 0.0061). The overall prevalence of KRAS and NRAS mutations was 45% and 2.5%. The overall prevalence of the BRAF V600E mutation was 5.8% and was more common in MSI-positive tumors (p < 0.0001). Regardless of MSI, BRAF-positive tumors were characterized by right-sided localization (p < 0.0001), category T3-4 (p = 0.013), lymph node involvement (p = 0.004), carcinomatosis (p = 0.046), high levels of CA19-9 (p = 0.014). HER2 amplification was found in 7% of wild-type RAS/BRAF cases and was associated with rectal cancer (p = 0.044), category T3-4 (p = 0.041), and distant metastases (p = 0.038). HER2 amplifications and NTRK translocations were not detected in cases with MSI.Conclusion. MSI-positive CRC had a higher prevalence of mutations in major genes. CRC with the BRAF V600E mutation and HER2 amplification had aggressive clinical and morphological parameters.