Red Blood Cell Distribution Width: A Potential Inexpensive Marker for Disease Activity in Patients with Rheumatic Diseases; Scoping Review

Background

Rheumatic diseases encompass a diverse group of autoimmune disorders that affect the joints and connective tissues. The red blood cell distribution width (RDW) has been widely investigated as an inflammatory marker. This scoping review aimed to explore the potential utility of RDW as an inexpensive marker for disease activity in patients with rheumatic diseases. By summarizing the available evidence, we aimed to determine whether RDW can serve as a reliable and accessible indicator of disease activity in these patients.

Methods

A comprehensive search was systematically performed across electronic databases, encompassing PubMed, Embase, and Web of Science. Studies have explored the relationship between RDW and disease activity in rheumatic diseases. Data extraction focused on the study characteristics, methodologies, and findings related to RDW as a disease activity marker.

Results

After removing duplicates, the initial search yielded 25 relevant studies. These studies encompassed a variety of rheumatic diseases, with rheumatoid arthritis being the most frequently studied condition. The association between RDW and disease activity was assessed by using various disease activity indices and clinical parameters. While some studies have reported a significant correlation between elevated RDW and disease activity, others have yielded inconclusive results.

Conclusion

From this review, we concluded that RDW is an inexpensive potential marker for the evaluation of disease activity in rheumatic diseases. RDW is promising as an inexpensive and readily available marker; however, its clinical utility in assessing disease activity in rheumatic conditions warrants more rigorous investigation through well-designed prospective studies.

Research-Relevant Clinical Pathology Resources: Emphasis on Mice, Rats, Rabbits, Dogs, Minipigs, and Non-Human Primates

Clinical pathology testing for investigative or biomedical research and for preclinical toxicity and safety assessment in laboratory animals is a distinct specialty requiring an understanding of species specific and other influential variables on results and interpretation. This review of clinical pathology principles and testing recommendations in laboratory animal species aims to provide a useful resource for researchers, veterinary specialists, toxicologists, and clinical or anatomic pathologists.

Brief Synopsis: "Instruction Manual for Juvenile Clinical Pathology"

This symposium synopsis summarizes key points discussed related to clinical pathology data interpretation for reproduction and juvenile toxicology studies. In pregnant and growing animals, several changes in clinical pathology parameters linked to growth/maturation of organ and physiological functions can occur, and understanding these changes is important to enable accurate interpretation of clinical pathology data. A brief overview of the general approach to clinical pathology data analysis according to contemporary practices is provided, followed by a discussion focused specifically on reproductive and juvenile clinical pathology. In this context, the approach to recognize and differentiate changes that may be related to pregnancy and growth as opposed to those that may be related to test article effects is highlighted.

Selected Aspects of Ocular Toxicity Studies With a Focus on High-Quality Pathology Reports: A Pathology/Toxicology Consultant's Perspective

Ocular toxicity studies are the bedrock of nonclinical ocular drug and drug-device development, and there has been an evolution in experience, technologies, and challenges to address that ensures safe clinical trials and marketing authorization. The expectations of a well-designed ocular toxicity study and the generation of a coherent, integrative ocular toxicology report and subreports are high, and this article provides a pathology/toxicology consultant's perspective on achieving that goal. The first objective is to cover selected aspects of study designs for ocular toxicity studies including considerations for contract research organization selection, minipig species selection, unilateral versus bilateral dosing, and in-life parameters based on fit-for-purpose study objectives. The main objective is a focus on a high-quality ocular pathology report that includes ocular histology procedures to meet regulatory expectations and a report narrative and tables that correlate microscopic findings with key ophthalmic findings and presents a clear interpretation of test article-, vehicle-, and procedure-related ocular and extraocular findings with identification of adversity and a pathology peer review. The last objective covers considerations for a high-quality ophthalmology report, which in concert with a high-quality pathology report, will pave the way for a best quality toxicology report for an ocular toxicity study.

N-acetylcysteine modulates cyclophosphamide-induced immunosuppression, liver injury, and oxidative stress in miniature pigs

Cyclophosphamide, a cytotoxic anticancer agent, induces immunosuppression and has several adverse effects. N-acetylcysteine alleviates oxidative stress, liver injury, and intestinal tissue damage. The present study examined whether N-acetylcysteine modulates the adverse effects of cyclophosphamide in pigs. Miniature pigs (n = 15) were used as an experimental model to evaluate the effects of N-acetylcysteine treatment on immune reactions, liver injury, and oxidative stress after cyclophosphamide challenge. Corn-soybean meal based dietary treatments were as follows: control diet with either saline injection, cyclophosphamide injection, or 0.5% N-acetylcysteine and cyclophosphamide injection. N-acetylcysteine increased the number of immune cells and decreased TNF-α production after cyclophosphamide injection and decreased TNF-α, IFN-γ, NF-κB, and IL-8 expression and increased IL-10 expression in peripheral blood mononuclear cells. Serum levels of alanine transaminase and aspartate aminotransferase decreased, superoxide dismutase activity increased, and malondialdehyde activity decreased following N-acetylcysteine treatment after cyclophosphamide injection. N-acetylcysteine decreases immunosuppression, liver injury, and oxidative stress in cyclophosphamide-challenged miniature pigs. The present study suggests that N-acetylcysteine has therapeutic application in livestock for modulating immune reactions, liver injury, and oxidative stress.

Consequences of parenteral iron-dextran loading investigated in minipigs. A new model of transfusional iron overload

Patients with blood transfusion-dependent anemias develop transfusional iron overload (TIO), which may cause cardiosiderosis. In patients with an ineffective erythropoiesis, such as thalassemia major, common transfusion regimes aim at suppression of erythropoiesis and of enteral iron loading. Recent data suggest that maintaining residual, ineffective erythropoiesis may protect from cardiosiderosis. We investigated the common consequences of TIO, including cardiosiderosis, in a minipig model of iron overload with normal erythropoiesis. TIO was mimicked by long-term, weekly iron-dextran injections. Iron-dextran loading for around one year induced very high liver iron concentrations, but extrahepatic iron loading, and iron-induced toxicities were mild and did not include fibrosis. Iron deposits were primarily in reticuloendothelial cells, and parenchymal cardiac iron loading was mild. Compared to non-thalassemic patients with TIO, comparable cardiosiderosis in minipigs required about 4-fold greater body iron loads. It is suggested that this resistance against extrahepatic iron loading and toxicity in minipigs may at least in part be explained by a protective effect of the normal erythropoiesis, and additionally by a larger total iron storage capacity of RES than in patients with TIO. Parenteral iron-dextran loading of minipigs is a promising and feasible large-animal model of iron overload, that may mimic TIO in non-thalassemic patients.

A miR-511-binding site SNP in the 3'UTR of IGF-1 gene is associated with proliferation and apoptosis of PK-15 cells

Insulin-like growth factor-1 (IGF-1) is a functional candidate gene for pig growth and development due to its crucial role in the growth axis of growth hormone-IGF-1. Considering that the 3' untranslated region (3'UTR) of gene may affect its expression, we analyzed the effect of a single-nucleotide polymorphism (SNP) (rs34142920, c.674C > T) on gene expression, cell proliferation, and apoptosis and the possible related molecular mechanisms in PK-15 cells. The SNP was found in the 3'UTR of IGF-1 in Bama Xiang pig in previous investigations. Results showed that the SNP was located at the target site binding to microRNA (miR-511). The 3'UTR of IGF-1 gene with C allele significantly downregulated the expression of IGF-1 gene compared with that of the gene with T allele by luciferase assay. miR-511 was transfected into porcine kidney cell line (PK-15 cells) to reveal its effects on cells and whether or not it targets IGF-1. The expression levels of IGF-1 at mRNA and protein levels were remarkably downregulated. miR-511 significantly inhibited cell proliferation and promoted cell apoptosis by downregulating the phosphorylation level of AKT and ERK1/2. This finding confirmed that miR-511 inhibits proliferation and promotes apoptosis by downregulating the IGF-1 in PK-15 cells.

Experimental non-alcoholic steatohepatitis in Göttingen Minipigs: consequences of high fat-fructose-cholesterol diet and diabetes

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease in humans, and ranges from steatosis to non-alcoholic steatohepatitis (NASH), the latter with risk of progression to cirrhosis. The Göttingen Minipig has been used in studies of obesity and diabetes, but liver changes have not been described. The aim of this study was to characterize hepatic changes in Göttingen Minipigs with or without diabetes, fed a diet high in fat, fructose, and cholesterol to see if liver alterations resemble features of human NAFLD/NASH.

METHODS

Fifty-four male castrated minipigs (age 6 to 7 months) were distributed into four groups and diet-fed for 13 months. Groups were: lean controls fed standard diet (SD, n = 8), a group fed high fat/fructose/cholesterol diet (FFC, n = 16), a group fed high fat/fructose/cholesterol diet but changed to standard diet after 7 months (diet normalization, FFC/SD, n = 16), and a streptozotocin-induced diabetic group fed high fat/fructose/cholesterol diet (FFC_DIA, n = 14). At termination, blood samples for analyses of circulating biomarkers and liver tissue for histopathological assessment and analyses of lipids and glycogen content were collected.

RESULTS

In comparison with SD and FFC/SD, FFC and FFC_DIA pigs developed hepatomegaly with increased content of cholesterol, whereas no difference in triglyceride content was found. FFC and FFC_DIA groups had increased values of circulating total cholesterol and triglycerides and the hepatic circulating markers alkaline phosphatase and glutamate dehydrogenase. In the histopathological evaluation, fibrosis (mainly located periportally) and inflammation along with cytoplasmic alterations (characterized by hepatocytes with pale, granulated cytoplasm) were found in FFC and FFC_DIA groups compared to SD and FFC/SD. Interestingly, FFC/SD also had fibrosis, a feature not seen in SD. Only two FFC and three FFC_DIA pigs had > 5% steatosis, and no hepatocellular ballooning or Mallory-Denk bodies were found in any of the pigs.

CONCLUSIONS

Fibrosis, inflammation and cytoplasmic alterations were characteristic features in the livers of FCC and FFC_DIA pigs. Overall, diabetes did not exacerbate the hepatic changes compared to FFC. The limited presence of the key human-relevant pathological hepatic findings of steatosis and hepatocellular ballooning and the variation in the model, limits its use in preclinical research without further optimisation.

Omega-3 fatty acids modulate cyclophosphamide induced markers of immunosuppression and oxidative stress in pigs

Immunosuppression directly correlates with economic benefits in livestock. Although omega-3, known as an energy source, is used as a pharmaceutical molecule, it remains unknown whether dietary supplementation with omega-3 can alleviate cyclophosphamide-induced immunosuppression in pigs. Omega-3 treatment increased the number of white blood cell, lymphocytes, and monocytes and decreased tumor necrosis factor (TNF)-α production under CTX challenge. In addition, we confirmed that omega-3 decreased the expression of nuclear factor (NF)-κB, TNF-α, interferon (IFN)-γ, and interleukin (IL)-8 in peripheral blood mononuclear cells. Additionally, omega-3 alleviated the activities of liver injury markers (alanine transaminase [ALT] and aspartate transaminase [AST]) and modulated oxidative stress markers (superoxide dismutase [SOD], malondialdehyde [MDA], and glutathione peroxidase [GPx]) in the blood serum after the CTX challenge. Based on these results, we suggest that omega-3 treatment modulates CTX-induced immunosuppression and oxidative stress in pigs. These results may have important implications in the development of new therapeutic approaches to improve immunosuppression, hepatic injury and dysfunction, and oxidative stress in pigs.

Scientific and Regulatory Policy Committee Points to Consider Review: Inclusion of Reproductive and Pathology End Points for Assessment of Reproductive and Developmental Toxicity in Pharmaceutical Drug Development

Standard components of nonclinical toxicity testing for novel pharmaceuticals include clinical and anatomic pathology, as well as separate evaluation of effects on reproduction and development to inform clinical development and labeling. General study designs in regulatory guidances do not specifically mandate use of pathology or reproductive end points across all study types; thus, inclusion and use of these end points are variable. The Scientific and Regulatory Policy Committee of the Society of Toxicologic Pathology (STP) formed a Working Group to assess the current guidelines and practices on the use of reproductive, anatomic pathology, and clinical pathology end points in general, reproductive, and developmental toxicology studies. The Working Group constructed a survey sent to pathologists and reproductive toxicologists, and responses from participating organizations were collected through the STP for evaluation by the Working Group. The regulatory context, relevant survey results, and collective experience of the Working Group are discussed and provide the basis of each assessment by study type. Overall, the current practice of including specific end points on a case-by-case basis is considered appropriate. Points to consider are summarized for inclusion of reproductive end points in general toxicity studies and for the informed use of pathology end points in reproductive and developmental toxicity studies.