Redblood Cell Distribution Width to Platelet Ratio (RPR): Novel diagnostic possibilities for perinatal disease in newborn foals

• Ano de defesa: 2022
• Autor(a) principal: Scalco, Rebeca
• Orientador(a): Curcio, Bruna da Rosa
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Pelotas
• Programa de Pós-Graduação: Programa de Pós-Graduação em Veterinária
• País: Brasil
• Palavras-chave em Português: Veterinária; Cavalos - Doenças; Neonatologia
• Área do conhecimento CNPq: CIENCIAS AGRARIAS
• Link de acesso: http://guaiaca.ufpel.edu.br/xmlui/handle/prefix/11560

Perinatal diseases are the leading cause of death among foals up to 7 days of age. Early clinical signs of diseases in neonatal foals are often non-specific, and untreated foals deteriorate rapidly. Therefore, early detection of the disease onset is essential. The development of rapid and accurate markers to aid in diagnosing neonatal foals is needed. The CBC parameters redblood cell distribution width (RDW) and RDW to platelet ratio (RPR) have been used in human medicine as markers of inflammation in many diseases. Therefore, the purpose of this work was to report the values of RDW and RPR in neonatal foals and to investigate their possible correlation with a risk score based on obstetric and clinical data. In this retrospective case-control study, 309 full-term Thoroughbred foals less than 24h old were clinically evaluated within 15 minutes after birth, and blood samples were collected within 24h of life. Foals showing an unremarkable physical examination, normal gestational length (320 to 365 days), adequate righting reflexes, and CBC values within the normal range were considered healthy. Foals that were born through dystocia, displayed delayed adaptative milestones (sternal recumbence > 5 minutes, suckling reflex > 20 minutes, stand >1 hour), gestational length > 365 days, and/or displayed physical/hematological characteristics of dysmaturity (silky hair-coat, domed head, floppy ears, abnormal granulocyte:lymphocyte ratio), were categorized in the group at-risk. Extracted data were assessed for normal distribution using the Shapiro-Wilk test. The Student’s T-test was used to evaluate the influence of groups and foal sex on hematological variables (RBC, hematocrit, hemoglobin, MCV, MCH, MCHC, RDW, platelets, WBC). Pearson's coefficient test was used to analyze the associations between gestational length and RDW, and RPR. Continuous variables are presented as mean ± SD. Categorical variables are presented as frequencies and percentages. All statistical analysis was conducted in the statistical package R Studio, and significance was set at P < 0.05. Based on the risk score, 221 (71.6%) foals were healthy, and 88 (28.4%) were considered at risk of developing perinatal disease (at-risk group). The mean gestational age for all the foals was 346.31 ± 9.69 days. RDW values did not differ between groups. Gestational length demonstrated to have a negative correlation with RDW (r = -0.156, P = 0.005) and MCV (r = -0.135, P = 0.01), indicating a link of these variables to foal maturity. RPR was higher for at-risk (0.073 ± 0.018) than for healthy foals (0.068 ± 0.014, P = 0.01). Therefore, the RPR ratio is a low-cost, readily accessible index and might be a promising early indicator of disease for the field triage of neonatal foals and rapidly estimate possible systemic disorders. For further expanding the applicability of RPR in neonatal foals, multicenter longitudinal studies with a larger number of healthy and critically ill neonates are necessary.