Increased concentrations of Serum amyloid A in dogs with sepsis caused by pyometra

Pyometra in Small Animals 3.0

Pyometra is a common disease in intact bitches and queens and occurs, although less frequently, in most other female pets. In bitches and queens, the illness is generally diagnosed within 4 months after estrus, in middle-aged to older individuals. Complications such as peritonitis, endotoxemia, and systemic inflammatory response syndrome are not uncommon and associated with more severe illness. Ovary-sparing surgical options such as hysterectomy could be considered in individuals with high-risk for detrimental side effects of spaying or without infection of the uterus but has not yet been evaluated for safety in pyometra.

Postoperative complications and antibiotic use in dogs with pyometra: a retrospective review of 140 cases (2019)

BACKGROUND

Pyometra is commonly seen in intact bitches and is usually treated by ovariohysterectomy. Few studies have reported the frequency of postoperative complications, particularly beyond the immediate postoperative period. Swedish national antibiotic prescription guideline provides suggestions about which antibiotics should be used and when in individuals undergoing surgery. Studies on how well clinicians adhere to these guidelines, and on the outcome for these patients, have not been evaluated for cases of canine pyometra. This retrospective study conducted at a private Swedish companion animal hospital assessed complications that developed within 30 days of pyometra surgery, and whether clinicians followed the current national guidelines in regard to antibiotic use. We also assessed whether antibiotic use affected the rate of postoperative complications seen in this cohort of dogs, where antibiotics were predominantly used in cases presenting with a more severely depressed general demeanour.

RESULTS

The final analysis included 140 cases, 27 of which developed complications. In total, 50 dogs were treated with antibiotics before or during surgery and in 90 cases, antibiotics were either not given at all or treatment was initiated postoperatively (9/90) due to a perceived risk of infection developing. Superficial surgical site infection was the most common complication, followed by an adverse reaction to the suture material. Three dogs died or were euthanised during the immediate postoperative period. Clinicians adhered to national antibiotic prescription guidelines on when antibiotics should be given in 90% of cases. SSI only developed in dogs that were not given pre- or intra-operative antibiotics, while suture reactions did not appear to be affected by antibiotic use. Ampicillin/ amoxicillin was used in 44/50 cases given antibiotics before or during surgery, including most cases showing signs of concurrent peritonitis.

CONCLUSION

Serious complications following the surgical treatment of pyometra were uncommon. Excellent adherence to national prescription guidelines was observed (90% of cases). SSI was relatively common and only seen in dogs that were not given antibiotics before or during surgery (10/90). Ampicillin/ amoxicillin was an effective first choice antimicrobial in cases requiring antibiotic treatment. Further studies are needed to identify cases benefiting from antibiotic treatment, as well as the duration of treatment needed to reduce the infection rate while also avoiding unnecessary preventive treatment.

Apolipoprotein A1 and serum amyloid A in dogs with sepsis and septic shock

Introduction

Apolipoprotein-A1 (Apo-A1) acts as a negative acute phase protein (APP) during inflammatory states, and has a potential prognostic value in people and dogs with sepsis. The aim of this retrospective study was to investigate the association of serum Apo-A1 concentration with disease severity, multiorgan dysfunction syndrome (MODS) and outcome in a population of dogs with sepsis, and to assess its correlation with major canine APPs.

Methods

Ninety-nine dogs with uncomplicated sepsis (n = 78) or septic shock (n = 21) were included. The serum concentration of Apo-A1, C-reactive protein (CRP) and serum amyloid A (SAA) were recorded, alongside the canine acute patient physiologic and laboratory evaluation fast (APPLE_fast) score and the presence of MODS.

Results

Dogs with septic shock had significantly lower serum Apo-A1 concentrations (106.3 ± 22.7 mg/dl; reference interval: 123.0-142.3 mg/dl), higher APPLE_fast score (30, 13-38) and greater frequency of MODS (67%) compared to those with uncomplicated sepsis (117.9 ± 19.3 mg/dl; 25, 6-33 and 8%, respectively) (P = 0.0201; P = 0.0005; P < 0.0001, respectively). Similarly, dogs with MODS had significantly lower serum Apo-A1 concentrations (104.1 ± 4.6 mg/dl) and higher APPLE_fast score values (31, 13-38) compared to those without MODS (118.32 ± 2.1 mg/dl and 26, 6-33, respectively) (P = 0.0050 and P = 0.0038, respectively). Conversely, neither CRP nor SAA were different between these groups. No difference in serum APPs concentrations was detected between survivors and non-survivors. Significant negative correlations were detected between serum Apo-A1 and SAA (P = 0.0056, r = -0.277), and between serum Apo-A1 and the APPLE_fast score (P = 0.0027, r = -0.3). In this population, higher values of the APPLE_fast score and the presence of MODS were independently associated with a higher risk of death.

Discussion

Our study shows that Apo-A1 is a useful biomarker of sepsis severity in dogs, since it is decreased in those with septic shock and MODS. Further prospective investigations are deemed to evaluate the applicability of Apo-A1 to predict sepsis course and response to treatment in septic dogs.

Evaluation of Resting Serum Bile Acid Concentrations in Dogs with Sepsis

Recent studies in the human literature suggest that serum bile acid concentrations could be an early predictor of short-term survival in critically ill patients. However, there is no available information in the veterinary literature regarding serum bile acid concentrations in dogs with sepsis. We aimed to evaluate if resting serum bile acid concentrations differ between septic and non-septic dogs. This was a retrospective observational study, of medical records at a single referral center over a twelve-year period. Twenty-six client-owned dogs diagnosed with sepsis were identified. Twenty-one dogs presenting with a non-hepatobiliary systemic disease and twenty-nine dogs admitted for an elective orthopedic procedure, considered otherwise healthy, were selected as control groups. Resting serum bile acid concentrations were significantly higher in the septic compared to the non-septic groups (ill control and orthopedic control groups). However, when assessing bile acid concentrations between groups individually, no difference was identified between the septic and the orthopedic control group. These results should be interpreted cautiously.

Serum Amyloid A as a Promising Biomarker in Domestic Animals’ Reproduction: Current Knowledge and Future Perspective

Simple Summary

Acute phase proteins (APPs) are useful markers which can be evaluated in animals to assess health status and characterize inflammation, infection, and trauma. Among APPs, serum amyloid A (SAA) has been widely investigated in pets and food-producing species as a possible biomarker of inflammatory and infective conditions, especially in the field of animal reproduction. The aims of this paper are to review the literature available on the use of SAA for the diagnosis and monitoring of inflammatory reproductive disease in animals, critically appraising the usefulness of such marker and summarizing the current state of knowledge.

Abstract

The investigation of acute phase proteins in veterinary medicine has opened the doors towards the identification and use of new markers for a timely assessment of health status in both companion and food-producing animals. The aim of this paper is to review the literature available on the use of serum amyloid A (SAA), an acute phase protein, for the diagnosis and monitoring of reproductive disorders in animals. This review critically appraises the usefulness of such marker in clinical practice and summarizes the current state of knowledge. Recent advances in the diagnosis and monitoring of reproductive diseases are presented, highlighting where SAA evaluation may enhance early diagnostic tools for dogs, cats, cattle, and equines.

Comparison of clinical and inflammatory parameters in dogs with pyometra before and after ovariohysterectomy

This study aimed to identify potential biomarkers of canine pyometra and their correlations with clinical parameters. First, 90 dogs with pyometra and 26 healthy female dogs were compared. Then, paired samples (before and after ovariohysterectomy) from 22 dogs with pyometra and 9 healthy controls from the initial cohort were compared. Concentrations of acute inflammatory proteins, C-reactive protein (CRP) and serum amyloid A (SAA), and cell-free DNA (cfDNA), were significantly higher in dogs with pyometra than in clinically healthy dogs. Cell-free DNA was the most sensitive biomarker for systemic inflammation, based on the receiver operating characteristic curve analysis (area under the curve = 0.959). In addition, cfDNA and CRP were significantly associated with inflammation and organ injury-related clinical parameters. Following the surgical removal of the inflamed uterus, interleukin-6 (IL-6), high-mobility group box 1 (HMGB1), and procalcitonin (PCT) significantly decreased, whereas changes in CRP, SAA, and cfDNA were not significant. These findings indicate that cfDNA, CRP, and SAA are potential clinical biomarkers of systemic inflammation in dogs with pyometra and PCT, IL-6, and HMGB1 are potential biomarkers of clinical recovery.

Changes in the Serum Protein Electrophoresis Profile in Dogs With Pyometra

Serum proteins are involved in the regulation of inflammation, and therefore, serum protein profiling provides important insights in diverse inflammatory reactions. Accordingly, concentrations of single APPs, such as the C-reactive protein (CRP), serum amyloid A (SAA), and haptoglobin (Hp), have been described as indicators of inflammatory response in canine pyometra. However, there is little information regarding the overall serum protein profile obtained by SPE in canine pyometra. The present study was thus aimed to identify changes in the serum protein profile to monitor inflammation in dogs with pyometra using serum protein electrophoresis (SPE), in addition to the analysis of the concentration of single acute phase proteins (APPs). By SPE analysis, decreased levels of albumin and elevated levels of α2-globulin and β-globulin were noted in dogs with pyometra. In addition, the concentration of APPs, including the C-reactive protein (CRP), serum amyloid A (SAA), and haptoglobin (Hp), were also elevated in dogs with pyometra. The present study provides fundamental data for inflammatory indicators of canine pyometra.

Measurement of ITIH4 and Hp levels in bitches with pyometra using newly developed ELISA methods

Measurement of acute phase proteins (APPs) as biomarkers in canine medicine is in increasing demand. In the present study, the development and validation of two ELISA methods for the quantification of canine inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4) and haptoglobin (Hp) are shown. The adequate imprecision and accuracy and wide analytical range make the developed methods appropriate to quantify ITIH4 and Hp in serum samples. The inter- and intra-assay CVs were lower than 10 %, and the assays maintained linearity under dilution and showed analytical equivalence with the method of radial immunodiffusion. The measurement of CRP, Hp and ITIH4 in sera from bitches affected by pyometra allowed us to determine that ITIH4 behaves as a moderate APP in dogs. The group of bitches affected by pyometra showed very high levels of CRP (147 ± 91 mg/L), corresponding to a strong inflammatory process, which resulted in a moderate increase in the concentrations of Hp (7 times) and ITIH4 (3 times) compared to the control group.

The plasma proteome and the acute phase protein response in canine pyometra

Canine pyometra is a common inflammatory disease of uterus in sexually mature bitches caused by secondary bacterial infection, leading to change in plasma proteins associated with the innate immune system. Proteomic investigation is increasingly being applied to canine diseases in order to identify and quantify significant changes in the plasma proteome. The aim of the study was to assess and quantify changes in plasma proteome profiles of healthy dogs and pyometra affected bitches using a TMT-based high-resolution quantitative proteomic approach. As a result, 22 proteins were significantly down-regulated including transthyretin, antithrombin, retinol-binding protein, vitamin D binding protein, paraoxonase 1, and kallikrein, while 16 were significantly up-regulated including haptoglobin light chain, alpha-1-acid glycoprotein, C-reactive protein precursor, and lipopolysaccharide-binding protein in dogs with pyometra. Pathway analysis indicated that acute inflammatory response, regulation of body fluid levels, protein activation cascade, the humoral immune response, and phagocytosis were affected in pyometra. Validation of biological relevance of the proteomic study was evident with significant increases in the concentrations of haptoglobin, C-reactive protein, alpha-1-acid glycoprotein, and ceruloplasmin by immunoassay. Pyometra in bitches was shown to stimulate an increase in host defence system proteins in response to inflammatory disease including the acute phase proteins. SIGNIFICANCE: The label-based high-resolution quantitative proteomics analysis and bioinformatic approach used in this study provide insight into the complex pathophysiology of inflammation associated with pyometra revealing proteins with biomarker potential. Early diagnosis and therapeutic intervention may prevent severe complications associated with advancing sepsis in dogs with pyometra. Therefore the identification of diagnostic biomarkers that, after clinical validation may be used in veterinary practice and protein relevant to pathways responding to disease are important findings of the study. Data are available via ProteomeXchange with identifier PXD015951.

Endometrial transcripts of proinflammatory cytokine and enzymes in prostaglandin synthesis are upregulated in the bitches with atrophic pyometra

Inflammatory markers of endometrial origin are valuable in order to differentiate the pyometra from cystic endometrial hyperplasia in the bitch. In the present study, we hypothesized that histological categorization would distinguish the differential regulation of the proinflammatory genes in the endometrium of bitches with pyometra. Ovariohysterectomy was done on bitches with confirmatory diagnosis of pyometra (n = 18). Using endometrium to myometrium ratio of 0.79 as threshold, the uteri (n = 8/group) were categorized into hyperplastic pyometra (HP) and atrophic pyometra (AP). Two samples were excluded as the diagnosis was inconclusive. In parallel, endometrial tissue was collected for total RNA extraction to study the differential expression of TLR4, IL-6, IL-8, COX-2 and PGFS through real time PCR. Diestrus uterus of non-pyometra bitches (n = 6) served as control. The mean fold change (2^-ΔΔCt) for the target genes was determined using β-actin as endogenous control and non-pyometra uterus as calibrator group. Except TLR4, other inflammatory genes were upregulated significantly by 1.82 to 3.74 times in the AP as compared to HP with maximum upregulation of COX-2 and PGFS. Further, correlation matrix with Spearman's rho revealed that IL-8 had strong positive correlation with COX-2 and PGFS in the AP group (P < 0.05). It is concluded that histological grading of pyometra into HP and AP revealed differential regulation of inflammatory cytokines and enzymes in the PG synthetic pathway in the canine endometrium that has diagnostic potential under clinical settings.

Determining prognosis in canine sepsis by bedside measurement of cell-free DNA and nucleosomes

OBJECTIVE

To investigate the use of plasma cell-free DNA (cfDNA) and nucleosome concentrations as prognostic biomarkers in canine sepsis.

DESIGN

Prospective, observational cohort study conducted from June 2015 to February 2016.

SETTING

University teaching hospital.

ANIMALS

Forty-five dogs with sepsis, 10 dogs with nonseptic systemic inflammatory response syndrome (nSIRS), and 15 healthy controls were consecutively enrolled and followed to hospital discharge. Patients were eligible for enrollment if they met ≥2 SIRS criteria and had a documented or highly suspected bacterial infection. Dogs <3 kg or with a known coagulopathy were excluded.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Acute Patient Physiology and Laboratory Evaluation scores (APPLE) were calculated and outcomes recorded. Plasma cfDNA was measured using a benchtop fluorimeter. Plasma nucleosome concentrations were determined by ELISA. Plasma nucleosome and cfDNA concentrations in dogs with sepsis or nSIRS were compared to those of healthy controls and cfDNA concentrations in septic dogs with and without bacteremia were compared. Associations between cfDNA concentrations and nucleosomes, leukocyte count, neutrophil count, and APPLE scores were evaluated. For septic dogs, cfDNA concentrations relative to neutrophil count and nucleosome concentrations in survivors and nonsurvivors were compared. Alpha was set at 0.05. cfDNA concentrations were significantly higher in dogs with sepsis or nSIRS compared to healthy controls (P < 0.0001 and P = 0.0034, respectively). Nucleosome concentrations were significantly higher in dogs with sepsis compared to healthy controls (P = 0.007). There was limited association between cfDNA and nucleosome concentrations (r_s  = 0.266), and no association between cfDNA concentration and leukocyte count, neutrophil count, and APPLE_full scores. Concentrations of cfDNA were positively correlated with APPLE_fast score (r_s  = 0.335, P = 0.025); however, cfDNA concentrations were significantly higher in dogs with bacteremia (P = 0.0299). In dogs with sepsis, cfDNA concentrations relative to neutrophil count were significantly higher in nonsurvivors than in survivors (P = 0.008).

CONCLUSIONS

In dogs with sepsis, high cfDNA concentrations relative to neutrophil count are associated with nonsurvival. Point-of-care cfDNA measurement may aid identification of bacteremia.

Utility and Prognostic Significance of Neutrophil-to-Lymphocyte Ratio in Dogs with Septic Peritonitis

Systemic inflammation is known to cause WBC abnormalities, specifically neutrophilia and lymphopenia. The neutrophil-to-lymphocyte ratio (NLR) is a simple and affordable biomarker that has been used in human clinical settings of sepsis but has not been investigated in veterinary species. We evaluated NLR in dogs with septic and nonseptic systemic inflammatory diseases and compared with a healthy dog population. An NLR ≥6 had an 84.39% sensitivity and 86.95% specificity to identify dogs with systemic inflammatory states; however, no ratio distinguished septic and nonseptic causes. The NLR was not associated with length of hospitalization, morbidity based on the acute patient physiologic laboratory evaluation scoring system, or mortality. The disassociation may be due to the retrospective nature of the study, including a restricted population size and acquisition of only a one-time blood sample. NLR is currently of limited use for diagnosis and prognosis in systemic inflammatory states in dogs, and larger, prospective studies are necessary to further evaluate NLR.

Molecular aspects of uterine diseases in dogs

Uterine diseases are common in dogs, particularly in countries where elective spaying is not usually performed. The associated clinical illnesses may be of varying degree ranging from merely decreased fertility to a critical pyometra requiring intensive care to survive. The diagnosis of some uterine diseases is generally uncomplicated, such as in a classic pyometra presenting with enlarged, fluid-filled uterus, purulent vaginal discharge and characteristic signs of illness or in other disorders associated with uterine enlargement. However, it can be more puzzling in diseases with normal uterine size and very mild or obscure clinical signs. It is important to recognize the uterine diseases early because of the risk of potentially life-threatening complications such as sepsis developing if treatment is delayed in cases where bacterial infection is present. In breeding bitches, an early diagnosis, that is when the disease has not developed extensively, will increase the possibility of non-surgical treatment options without increased risk and thereby also increasing chances of maintained fertility. Early diagnosis and treatment initiation are thus favourable for complete recovery, also in less severe uterine diseases and those without infection. Molecular markers are molecules in biological samples that can be measured for diagnostic purposes, outcome prediction, and for gaining more information about different physiological and pathological conditions. Examples of commonly evaluated markers include laboratory variables analysed in blood, urine, cytological or tissue biopsy samples. Regarding the genetic pre-disposition for different uterine diseases in dogs, information is lacking. Recently, the global gene expression in uterine tissue in dogs has been investigated more closely, and newly developed technologies provide excellent opportunities for identifying molecular markers worth exploring further. The focus of this review article is to highlight findings on markers relevant for diagnosis, prediction of prognosis and treatment outcome in the most common uterine diseases in dogs.

Closed cervix is associated with more severe illness in dogs with pyometra

Background

Pyometra, a life-threatening bacterial infection of the uterus, is classified as open or closed depending on the functional patency of the cervix i.e. presence or absence of vaginal discharge. In closed cervix pyometra, pus and bacterial products accumulate in the uterus, which is thought to induce a more severe illness. The aim of this study was to investigate whether disease severity or outcome differed in dogs with open or closed cervix pyometra.

Results

Prospectively collected data from 111 female dogs diagnosed with pyometra at the University Animal Hospital, Swedish University of Agricultural Sciences, Uppsala, intermittently during 2005–2012 was analyzed. Seventy-two dogs (65%) had open cervix, whereas 39 dogs (35%) had closed cervix. Differences between the two groups were explored by Wilcoxon Two Sample Test for continuous variables and Chi-square or Fisher’s exact test for categorical variables. P < 0.05 was considered significant.

In dogs with open cervix the median age was 9.0 years and the median weight 26.0 kg. In dogs with closed cervix the median age was 9.6 years and the median weight 25.0 kg, with no significant differences between the groups (p = 0.69 and 0.24, respectively). Five dogs (4.5%) died, all with open cervix, and 16 dogs (14%) had complications.

The general physical condition was moderately or severely depressed in 30% (21/71) of dogs with open cervix (severely depressed in 4 dogs, moderately depressed in 17 dogs) and in 56% (22/39) of dogs with closed cervix (severely depressed in 3 dogs, moderately depressed in 19 dogs). The general physical condition was mildly depressed in 41 dogs with open cervix and 16 dogs with closed cervix, whereas it was normal in nine dogs with open cervix and one dog with closed cervix. None of the included dogs had very severely depressed general physical condition or were non-responsive.

Leukocytosis, neutrophilia, monocytosis and moderately to severely depressed general condition was more commonly found in dogs with closed cervix (p = 0.003, p = 0.008, p = 0.003 and p = 0.006, respectively).

Sepsis was more commonly present in closed cervix pyometra (77%, 30/39 dogs) compared to open cervix pyometra (51%, 36/71 dogs) (p = 0.007). Presence of prolonged postoperative hospitalization did not differ significantly between the two groups.

Conclusions

In dogs with closed cervix, sepsis was more common, the general physical condition more often moderately to severely depressed and leukocytosis, neutrophilia and monocytosis more frequently found. The results showed that closed cervix was associated with a more severe illness than open cervix at admission but not with poorer outcome as measured by postoperative hospitalization. These findings may be clinically valuable for optimizing monitoring and treatments in dogs with the disease.

Blood pressure and heart rate during ovariohysterectomy in pyometra and control dogs: a preliminary investigation

BACKGROUND

Surgery causes a stress response, a physiologic response to trauma. The intraoperative surgical stress response in dogs diagnosed with pyometra has not previously been described. The aim of this study was to investigate the intraoperative surgical stress response, assessed by blood pressure and heart rate measurements, in dogs diagnosed with pyometra and healthy controls. All dogs were premedicated with acepromazine and methadone, anaesthesia was induced with propofol and maintained with isoflurane, where after the dogs were subjected to ovariohysterectomy.

RESULTS

Eight dogs diagnosed with pyometra and eight healthy controls were used. Systolic blood pressure and heart rate were measured to assess the surgical stress response. Additionally propofol dosage at induction of anaesthesia and the end-tidal isoflurane concentration were investigated. The surgery was split into four phases. Phase 0 was the period 10 min before the skin incision, phase 1 was skin incision and opening of abdomen, phase 2 was manipulation of uterine horns, lifting of the ovary with stretching of the mesovarium, ligation and transection of mesovarium and phase 3 was ligation and transection of cervix, removal of organs and closing of the abdomen. Dosage of propofol at induction of anaesthesia was 3.6 ± 1 mg/kg in dogs with pyometra and 4.1 ± 1 in healthy controls (P = 0.37). In both groups, systolic blood pressure increased between phase 1 and 2, from 87 ± 15 to 114 ± 19 mmHg in dogs with pyometra, and from 88 ± 18 to 106 ± 20 mmHg in healthy controls, (both P < 0.0001). Systolic blood pressure did not differ significantly between groups in any of the phases. Heart rate and end-tidal concentration of isoflurane did not differ significantly between phases or between groups.

CONCLUSIONS

The increased blood pressure at removal of ovaries during ovariohysterectomy suggests a pronounced noxious stimulus at this part of the procedure. In principle, the study parameters and response to surgery did not differ significantly between dogs with pyometra and healthy controls.

Serum IL-6 and IL-10 concentrations in bitches with pyometra undergoing ovariohysterectomy

Background

Pyometra is a serious bacterial infection of the uterus affecting female dogs and manifests as an accumulation of pus in the uterine lumen. The aim of the study was to assess changes in serum interleukin (IL)-6 and IL-10 concentrations in bitches with pyometra undergoing ovariohysterectomy.

Findings

Blood samples were collected from healthy bitches (controls) and bitches with pyometra before surgery, and 3 and 10 days after ovariohysterectomy. Before surgery, bitches with pyometra had significantly higher serum concentrations of IL-6 and IL-10 than the controls. After surgery, the serum concentration of IL-6 and IL-10 decreased significantly. In healthy dogs, the concentration of IL-6 and IL-10 showed a significant increase 3 days after surgery followed by a decrease on day 10.

Conclusion

An increase in serum concentrations of IL-6 and IL-10 was present before surgery in bitches with pyometra and 3 days after ovariohysterectomy in healthy controls. Concentrations decreased after ovariohysterectomy and/or proper healing, suggesting that these cytokines can be useful for assessment of the postoperative period in bitches.