New insights into the natural course of knee osteoarthritis: early regulation of cytokines and growth factors, with emphasis on sex-dependent angiogenesis and tissue remodeling. A pilot study.

OBJECTIVE: This study was conducted to identify cytokine profiles associated with radiographic phenotypes of knee osteoarthritis (rKOA) with a focus on early stage of the disease. METHODS: The pilot population study involved 60 middle-aged patients (mean age 50 ± 7.3y.). Standardized weight-bearing anteroposterior and axial radiographs were used to assess rKOA severity in tibiofemoral (TFJ) of patellofemoral joint (PFJ) by grading system (grades 0-3). Luminex (xMAP®) technology was used to simultaneously assess 60 biomarkers (BMs). RESULTS: Several pathways of angiogenic (CXCL10/IP-10, FGF1/2, PDGF-AA/BB, ANG1, RANTES), tissue remodeling/fibrosis (MMP1/3, TIMP2/3/4, TGFß), and fat tissue (leptin) BMs associated with rKOA severity already in very early phase (grade 1). We identified several sets of cytokines as key markers of early knee osteoarthritis (KOA) predicting radiographic features in logistic-regression models (AUC = 0.80-0.97). Marked sex-specificity of rKOA course was detected: upregulation of angiogenesis dominated in females, whereas the activation of tissue remodeling was dominant in males. Several of these shifts, e.g., decrease of CXCL10/IP-10, took place only in grade 1 KOA and disappeared or reversed in later stages. OA of different knee-joint compartments has distinct profiles of cytokines. A broad list of BMs (TIMP2/3/4, MMP1/3, TGFß1/2, vWF-A2, sE-selectin and leptin) associated with OA in the PFJ. CONCLUSION: Our results demonstrate that substantial and time-limited shifts in the angiogenic and TIMP/MMP systems occur in the early stage of KOA. Our study findings highlight the sex-, grade- and compartment-dependent shifts in above processes. The data may contribute to the individualized prevention of KOA in the future.

Association of ADAM12-S protein with radiographic features of knee osteoarthritis and bone and cartilage markers.

ADAM12 (A disintegrin and metalloprotease) is one of the candidate genes demonstrating susceptibility to osteoarthritis. The purpose of this study was to investigate the relationship between ADAM12-S protein and radiographic knee osteoarthritis (KOA) and its correlation to several bone and cartilage biomarkers. The ADAM12-S protein was measured in 276 subjects (60% women, aged 32-60 years), including 181 individuals with and 95 without radiographic KOA features. The radiographs were obtained from both tibiofemoral (TF) and patellofemoral (PF) joints. The serum levels of ADAM12-S protein were measured by DELFIA1/AutoDELFIA research kit. The ADAM12-S protein was found in detectable ranges in 43 subjects (16 men), without statistical difference between the two genders. In the whole group, the ADAM12-S was related to radiographic KOA grades in TF (P = 0.004) as well in PF joint (P = 0.003). We also found a correlation between ADAM12-S protein and osteophytes in TF and/or PF joints (P = 0.003). No correlations were found between serum levels of S-CTx-I (C-terminal cross-linked telopeptides of type I collagen) or S-PINP (type I procollagen N-terminal propeptide) and ADAM12-S. Similarly, in the whole group, the ADAM12-S protein was not correlated with U-CTx-II (urinary C-telopeptide fragments of type II collagen); however, in the female group, trend to positive correlation between the investigated biomarkers (P = 0.019) was observed. The ADAM12-S protein could be elevated in some KOA cases, and this elevation correlates with the grades of the disease, mostly owning to development of osteophytes. This finding suggests the possible involvement of the ADAM12-S protein in the pathogenesis of KOA.

Missense single nucleotide polymorphism of the ADAM12 gene is associated with radiographic knee osteoarthritis in middle-aged Estonian cohort.

OBJECTIVE: One of the recognized candidate genes of osteoarthritis (OA) is the ADAM metallopeptidase domain 12 (meltrin alpha) gene. We investigated the potential role of two single nucleotide polymorphisms (SNP) of the ADAM12 gene in susceptibility to radiographic knee OA and its progression in an Estonian cohort. METHODS: The rs3740199 and rs1871054 polymorphisms were genotyped according to restriction fragment polymorphism in a population-based cohort consisting of 189 subjects selected from the age group 32-55 years. The radiological features of OA were measured in the tibio- and patellofemoral joints (PFJ). The X-ray investigation was repeated 3 years later for estimation of OA progression. RESULTS: We found statistically significant association between rs3740199 polymorphism and patellofemoral OA in male patients (P=0.014), genetic risk was mostly related to CC homozygosity. The same SNP also affected the presence of advanced grade (II+III) osteophytes in the whole group (P=0.042) and the occurrence of osteophytes on the patellar margins in the PFJ (P=0.046). In OA progression the most significant association was found between joint space narrowing of the tibiofemoral joint and rs3740199 SNP in women (P=0.018). The rs1871054 polymorphism was not related to OA susceptibility or to progression traits. In our study the haplotype GC (rs3740199/rs1871054) was associated with reduced risk for development of osteophytes in the PFJ (P=0.041). CONCLUSIONS: We conclude that rs3740199 polymorphism may affect occurrence of knee OA and its progression. We also hypothesize that the genetic contribution of ADAM12 to OA is remarkably gender-dependent and anatomical site-specific.

[Helicobacter pylori and chronic gastritis in the gastric biopsy material in a group of randomly selected adult inhabitants of Estonia]. / Helicobacter pylori i khronicheskii gastrit v gastrobiopsiinom materiale v gruppe sluchainoi vyborki vzroslykh zhitelei Estonii.

The occurrence of Helicobacter pylori (HP) was examined in 227 subjects randomly selected among the Estonian population of town Kuressaare. HP was present in 166 subjects (73%). In cases of normal mucosa both in antrum and body HP was lacking. If normal gastric body mucosa was associated with antral gastritis HP was found in both regions. More often the contamination of antral and body mucosa with HP occurred in case of superficial gastritis. In subjects with atrophic gastritis the occurrence of HP decreased. The frequency of HP was high (58%) already in the age group of 15-19 years and increased to 83% at the age of 20-29 years. In subjects over 60 years it decreased due to the development of atrophic gastritis.

[Micro-ecological aspects of studies on the effect of antibacterial drugs on intestinal microflora]. / Mikroékologicheskie aspekty izucheniia vozdeistviia antibakterial'nykh preparatov na mikrofloru kishechnika.

Possible characterization of intestinal microflora as an integral system after exposure to antibacterial drugs was studied. Microflora of the contents and mucosa of the jejunum and large intestine in control rats and in rats exposed to metronidazole was studied and numerical indicators characterizing ratios of dominating and accompanying microbial groups in the intestine biotope++ were developed. With this purpose the proportion of the microbial groups in the total quantity of the microbes of a microbiocenosis was determined by the data on microflora quantitative composition. On the basis of detected wide species variety of microorganisms potentially dominating by their biotope numerical limits of the norm were determined only for the microbial groups of the accompanying microflora. The total proportion of the accompanying microbial populations under the normal conditions and the detected measure of deviation (reverse, partial) from the ratio of the dominating and accompanying microorganisms peculiar of the given biotope++ in separate subjects promoted estimation of microbiocenoses of definite biotope of the intestine as a whole.

[Effect of antibiotics on intestinal microflora and production of metabolites]. / Vliianie antibiotikov na kishechnuiu mikrofloru i produktsiiu metabolitov.

Methodical approaches to detection of relation between intestinal microflora and its metabolites are described. The microbial origin of certain compounds can be asserted by a decrease in their production after exposure to antibacterial drugs or the absence of their production in microbe-free animals. The authors consider that parallel investigation of intestinal microflora and its metabolites after exposure to various agents e.g. narrow spectrum antibiotics or specific substrates is the most accurate methodical approach to detection of their interrelations. Data on the effect of four drugs i.e. kanamycin, metronidazole, cefotaxime and bactrim on production of 10 bacterial metabolites: p-cresol, phenol, indican, acetic, propionic, butyric, isobutyric, valeric, isovaleric and caproic acids in rats are presented. Correlation between the metabolites and the intestinal microflora composition was revealed. It is concluded that detection of microorganisms responsible for production of definite metabolites requires at the maximum: (1) exposure to drugs of different spectra, (2) detection of changes in intestinal microflora by biotope++ and (3) investigation of mucosa microflora which more exactly characterizes metabolism of definite biotops.

[Metabolites of the intestinal microflora in the diagnosis of intestinal dysbacteriosis]. / Metabolity kishechnoi mikroflory v diagnostike disbioza kishechnika.

The procedures most widely used in investigation of intestinal microflora activity are briefly reviewed. The original findings relating to investigation of intestinal microflora and isolation of certain bacterial metabolites from rats with self-filling jejunal loop are presented as an example. Marked correlation between isolation of certain bacterial metabolites and self-filling jejunal loop microflora was observed. The authors consider advisable that biochemical and bacteriological methods for investigation of intestinal microflora be combined. When there are shifts in the number and ratio of the produced metabolites, invasive diagnostic methods including intubation and bacteriological examination of the small intestine are recommended.

Biochemical activity of intestinal microflora in adult coeliac disease.

In order to answer up to now open questions regarding the role of the microflora in the pathophysiology of adult coeliac disease the excretion of bacterial metabolites in urine has been followed. Unusual high outputs of p-cresol and/or phenol were found in almost all patient, whereas an increased excretion of indican could be observed in a few persons, only. The response to short-term antibacterial therapy was variable.