Comparison of the biopsy and cytobrush techniques for diagnosis of subclinical endometritis in mares

BACKGROUND

Endometritis is a major cause of infertility in the mare. Therefore, the diagnosis of this disease is very important in veterinary practice. The objective of this study was to compare bacteriological and cytological results obtained from the mare uterus using biopsy (EB) and cytobrush (CB) techniques and relating these findings to the presence of polymorphonuclear cells (PMNs) in endometrial tissue as the gold standard for detection of endometritis. In particular, we tested the hypothesis that endometrial cytology and microbiology data obtained from material collected using the EB and CB techniques are similar, so that the CB technique could preferentially be used to detect subclinical endometritis in clinical practice.

METHODS

A total of 69 mares suspected of subclinical endometritis because of previous reproductive history and 15 maiden mares were enrolled in this study. Material collected from both EB and CB was smeared on sterile glass slides for cytological examinations and on culture media for microbiological examinations. Bacteriological cultures and cytological samples were classified as negative (no growth or mixed cultures of more than three microorganisms; <2% PMNs) or positive (pure growth of microorganisms; >2% PMNs) for endometritis.

RESULTS

Positive growth was observed in 43% of CB samples and in 54% of EB samples (difference not significant). The growth of β-hemolytic streptococci was always connected with positive cytology. This relationship was not observed for growth of E. coli or for non-pathogenic flora. The sensitivity of bacterial growth and cytology from EB was 0.63 and 0.73 respectively. The sensitivities of bacterial growth and cytology from CB were 0.50 and 0.71 respectively.

CONCLUSION

Microbiological and cytological results obtained from CB are similar to those obtained from EB and based on these findings the CB technique may be recommended for collection of materials from the mare's uterus in clinical practice.

Short communication: Proinflammatory gene expression relative to the collection technique of endometrial samples from cows with and without subclinical endometritis

Uterine inflammation negatively affects reproductive performance and is an important cause of infertility and subfertility in dairy cows. Several studies have investigated the use of gene expression in endometrial samples collected by biopsy or cytology to evaluate the inflammatory response of the cow uterus. This study aimed to compare the expression of the CCL5, CXCL8, IL6, and IL1B genes in the bovine endometrium according to the site of sample collection [caruncular (C) or intercaruncular (IC)], the collection method (biopsy or cytology), and the category of inflammation based on endometrial cytology (zero, medium, or high) in subclinical endometritis. The reproductive tracts of dairy cows were collected from a slaughterhouse, and punch-biopsy samples of endometrial tissues were obtained from both regions (C and IC). Endometrial cells from these regions were collected with the cytobrush technique and then used for the analysis of mRNA expression by quantitative PCR. After counting polymorphonuclear cells (PMN) by endometrial cytology, 20 uteri with an ovary at stage I (d 1-4 of estrous cycle) were categorized into 3 groups. Uteri with 0% PMN (n = 10) were assigned to group zero, uteri with 5 to 15% PMN (n = 5) to group medium (12.2 ± 1.6% PMN), and uteri with >15% PMN (n = 5) to group high (53.8 ± 32.9% PMN). All data were analyzed with 2-way ANOVA with Bonferroni multiple comparison post test. The results from gene transcripts demonstrated that the region (C or IC) of the endometrial biopsy had no influence on any of the degrees of inflammatory reaction observed. However, gene expression was more elevated in the endometrium of cows with greater inflammation compared with those without inflammation (CCL5, CXCL8, IL6, IL1B) and those with medium inflammation (CCL5, IL6). Expression of the genes evaluated did not differ between the endometrium without inflammation and with medium inflammation. However, in the high inflammation group, all genes were comparatively more expressed in samples collected by cytology relative to those derived from biopsies for both anatomical regions. In conclusion, gene expression did not differ between the C and IC tissue. Samples collected from animals with greater inflammation had greater gene expression than those with zero or medium inflammation. In addition, cytology samples had greater gene expression than biopsy samples in the high inflammation group.

Impression cytology as diagnostic tool in horses with and without ocular surface disease

BACKGROUND

Cytology plays a major role in the diagnosis of ocular surface diseases.

OBJECTIVE

To compare 2 cytological sampling methods for obtaining corneal and conjunctival cell samples regarding irritation for the patient, invasiveness, sample quality and diagnostic equivalence.

STUDY DESIGN

Observational prospective study.

METHODS

In 5 healthy horses, conjunctival and corneal samples were taken bilaterally by impression cytology sampling (ICS) and cytobrush sampling (CBS). Irritation and invasiveness were assessed with an eye irritation and an epithelial damaging score system, respectively. Sample quality was evaluated via morphometric analysis and graded by a board certified clinical pathologist. For the assessment of diagnostic equivalence, 15 eyes of 14 client owned horses with ocular surface anomalies were sampled by ICS and CBS. The methods were compared regarding the types of inflammatory cells and/or infectious agents detected and if the correct diagnosis could be achieved. Histopathology served as gold standard when available.

RESULTS

ICS was significantly less invasive and less irritating for the horses. Both methods retrieved cells of overall high quality; the cell quantity was significantly higher in IC samples. ICS preserved the natural cellular layout. There was a fair, but no statistically significant agreement between the diagnostic outcomes between sampling methods although CBS resulted in a slightly greater variability of inflammatory cell types compared to ICS.

MAIN LIMITATIONS

None.

CONCLUSIONS

Because of its low irritability and invasiveness ICS can be recommended for cell sampling in fragile corneas and for experimental studies. ICS is especially useful in cases where preservation of cellular layout is advantageous. CBS samples are easier to obtain because of the small equine palpebral fissure. Additionally, the identification of inflammatory cells within conjunctival cell samples is easier. Overall, CBS is still an appropriate method in clinical settings.

Comparison of diagnostic methods for uterine health in dairy cattle on different days postpartum

BACKGROUND

Uterine health status is a key factor for dairy management.

METHODS

The uteri of 28 Holstein cows were assessed weekly by three different methods: ultrasonography (UT), Metricheck device (MT) and cytobrush (CYT), during two weeks to seven weeks postpartum.

RESULTS

The percentage of cows with an MT-positive, UT-positive and CYT-positive result decreased dramatically at three weeks, four weeks and five weeks postpartum, respectively. The agreement of the results was poor or weak within six weeks postpartum (κ=0.09-0.35), and only at seven weeks moderate or good agreement was achieved (κ=0.60-0.70). When comparing the results obtained by UT and MT, 30 per cent or more of the total cows had conflicting results from postpartum three weeks to six weeks. The uterine health of cows was re-evaluated by the combined usage of UT and MT referring to CYT. The highest sensitivity was achieved when positive individuals were identified as either MT-positive or UT-positive, whereas the highest specificity occurred when results were positive by both MT- and UT- methods.

CONCLUSION

The accuracy of early postpartum uterine health status by three methods depended heavily on the time postpartum. The combined use of UT and MT is a practical candidate for cow-side monitoring method of uterine health.

Cytological variations and typical diagnostic features of endocervical adenocarcinoma in situ: A retrospective study of 74 cases

Background:

The sensitivity of Papanicolaou smears for detecting endocervical adenocarcinoma in situ (AIS) is very low. A comprehensive cytological analysis of endocervical AIS is necessary to increase diagnostic accuracy.

Methods:

The subjects were 74 patients with pathologically-diagnosed AIS. A total of 140 Papanicolaou smears were reviewed to calculate the sensitivity of the Papanicolaou smears for detecting AIS and the incidence of sampling/screening/diagnostic errors. The cytological review was performed by 6 cytotechnologists, and the final cytological diagnosis was obtained at the consensus meeting. We classified the cases into three differentiation types; typical type (well-differentiated AIS), polymorphic type (poorly differentiated AIS), and mixed typical and polymorphic type. Three cytological subtypes (endocervical, endometrioid and intestinal subtypes) of AIS were also analyzed.

Results:

The sensitivity of the original Papanicolaou smears for the detection of AIS was 44.6%, while that for the detection of AIS and adenocarcinoma was 63.5%. The diagnostic accuracy of AIS increased to 78.5% in the final diagnosis. The common characteristic features were microbiopsies/hyperchromatic crowded groups (HCG) (82.0%) and mitotic figures (72.2%). The appearance of single cells (2.8%) was rare, and all the cervical cytology smears showed no evidence of necrotic tumor diathesis. The most common AIS was the typical type (41 cases, 67.2%) among all cytologically-diagnosed AIS or adenocarcinoma cases (61 cases). Although mixed typical and polymorphic AIS existed in 17 cases (27.9%), pure polymorphic AIS was very rare (3 cases, 4.9%). The endocervical subtype was the most predominant subtype (67.2%), followed by a few mixed subtypes. The important diagnostic keys for AIS cytology are as follows: (1) The appearance of microbiopsies/HCG (single-cell pattern is rare), (2) mitotic figures in the microbiopsies/HCG, (3) a lack of necrotic tumor diathesis in cases with polymorphic AIS, and (4) recognition of typical cytological subtypes.

Conclusions:

The relatively low diagnostic accuracy AIS was caused by the underestimation of microbiopsies/HCG and the overestimation of polymorphic components. The typical cytological features of AIS are the presence of microbiopsies/HCG with mitotic figures in the absence of necrotic tumor diathesis in specimens containing endocervical samples. The recognition of infrequent AIS subtypes (endometrioid and intestinal subtypes) is also important.

Deciphering the Role of Mucosal Immune Responses and the Cervicovaginal Microbiome in Resistance to HIV Infection in HIV-Exposed Seronegative (HESN) Women

The female genital tract (FGT) is an important site of human immunodeficiency virus (HIV) infection. Discerning the nature of HIV-specific local immune responses is crucial for identifying correlates of protection in HIV-exposed seronegative (HESN) individuals. The present study involved a comprehensive analysis of soluble immune mediators, secretory immunoglobulins (sIg), natural killer (NK) cells, CXCR5⁺ CD8⁺ T cells, T follicular helper (Tfh) cells, and T regulatory cells (Tregs) in the vaginal mucosa as well as the nature and composition of the cervicovaginal microbiome in HESN women. We found significantly elevated antiviral cytokines, soluble immunoglobulins, and increased frequencies of activated NK cells, CXCR5⁺ CD8⁺ T cells, and Tfh cells in HESN females compared to HIV-unexposed healthy (UH) women. Analysis of the genital microbiome of HESN women revealed a greater bacterial diversity and increased abundance of Gardnerella spp. in the mucosa. The findings suggest that the female genital tract of HESN females represents a microenvironment equipped with innate immune factors, antiviral mediators, and critical T cell subsets that protect against HIV infection.

IMPORTANCE The vast majority of human immunodeficiency virus (HIV) infections across the world occur via the sexual route. The genital tract mucosa is thus the primary site of HIV replication, and discerning the nature of HIV-specific immune responses in this compartment is crucial. The role of the innate immune system at the mucosal level in exposed seronegative individuals and other HIV controllers remains largely unexplored. This understanding can provide valuable insights to improve vaccine design. We investigated mucosal T follicular helper (Tfh) cells, CXCR5⁺ CD8⁺ T cells, natural killer (NK) cells subsets, soluble immune markers, and microbiome diversity in HIV-exposed seronegative (HESN) women. We found a significantly higher level of mucosal CXCR5⁺ CD8⁺ T cells, CD4⁺ Tfh cells, activated NK cell subsets, and antiviral immune cell mediators in HESN women. We also found a higher abundance of Gardnerella spp., microbiome dysbiosis, and decreased levels of inflammatory markers to be associated with reduced susceptibility to HIV infection. Our findings indicate that increased distribution of mucosal NK cells, CXCR5⁺ CD8⁺ T cells, Tfh cells, and soluble markers in HIV controllers with a highly diverse cervicovaginal microbiome could contribute effectively to protection against HIV infection. Overall, our findings imply that future vaccine design should emphasize inducing these highly functional cell types at the mucosal sites.

A new method for oral cancer biomarkers detection with a non-invasive cyto-salivary sampling and rapid-highly sensitive ELISA immunoassay: a pilot study in humans

Introduction

Oral squamous cell carcinoma (OSCC) accounts for approximately 90% of oral malignancies and has a 5-year mortality rate close to 50%. A consistent part (70%) of all oral cancers is diagnosed at an advanced stage since available screening techniques are ineffective. Therefore, it would be urgent to improve them. The diagnostic gold standard is tissue biopsy with histological and immunohistochemical assessment. This method presents some limitations. Biopsy is invasive and the histopathological evaluation is semi-quantitative, and the absolute abundance of the target cannot be reliably determined. In addition, tissue is highly processed and may lead to loss of information of the natural state. The search for classical and new clinical biomarkers on fragments of tissue/cells collected with a cytobrush is a highly hopeful technique for early detection and diagnosis of OSCC, because of its non-invasive sampling and easy collection method.

Methods

Here we analyzed cytobrush biopsies samples collected from the oral cavity of 15 patients with already diagnosed OSCC by applying an innovative high-sensitivity ELISA technique, in order to verify if this approach may provide useful information for detection, diagnosis, and prognosis of OSCC. To this end, we selected six biomarkers, already used in clinical practice for the diagnosis of OSCC (EGFR, Ki67, p53) or selected based on recent scientific and clinical data which indicate their presence or over-expression in cells undergoing transformation and their role as possible molecular targets in immunecheckpoints blockade therapies (PD-L1, HLA-E, B7-H6).

Results

The selected tumor biomarkers were highly expressed in the tumor core, while were virtually negative in healthy tissue collected from the same patients. These differences were highly statistically significant and consistent with those obtained using the gold standard test clearly indicating that the proposed approach, i.e. analysis of biomarkers by a custom ELISA technique, is strongly reliable.

Discussion

These preliminary data suggest that this non-invasive rapid phenotyping technique could be useful as a screening tool for phenotyping oral lesions and support clinical practice by precise indications on the characteristics of the lesion, also with a view to the application of new anti-tumor treatments, such as immunotherapy, aimed at OSCC patients.

Hormonal regulation of oviductal glycoprotein 1 (OVGP1; MUC9) in the rhesus macaque cervix

BACKGROUND

Macaques are outstanding animal models for the development of new contraceptives. In women, progestin-only contraceptives often fail to block ovulation and are believed to act by altering cervix physiology. Herein, we assessed oviductal glycoprotein 1 (OVGP1) in the macaque cervix as a marker for progestogen action.

MATERIALS

Rhesus macaques were treated with estradiol (E₂ ), E₂ plus progesterone (P), and E₂ plus levonorgestrel (LNG), a contraceptive progestin. Samples consisted of archived blocks of midcervix mucosa (epithelium and lamina propria) and fresh epithelial cells collected non-invasively by cytobrush. OVGP1 was assayed by quantitative real-time PCR and localized by immunocytochemistry.

RESULTS

OVGP1 transcript was maximal after E₂ and reduced after treatment with E₂  + P (P < .05). LNG also reduced OVGP1 expression (P < .05). OVGP1-specific staining localized to epithelial cells, and transcript was quantifiable in cytobrush collected samples.

CONCLUSIONS

OVGP1 expression in cytobrush samples of macaque cervix provides a non-invasive indicator of contraceptive progestin action.

Prevalence of HPV in patients affected by oral Lichen planus: A prospective study using two different chair-side sampling methods

BACKGROUND

Human Papillomavirus (HPV) role in oral potentially malignant lesions remains unclear. Aims of this study were to evaluate the prevalence of HPV infection in a cohort of patients affected by oral lichen planus, to analyze the genotypes involved, and to compare the performance of two specimen collection methods: brushing and biopsy.

METHODS

Consecutive patients with oral lichen planus were enrolled. Each patient's clinical and anamnestic data were recorded before he/she underwent brushing and biopsy procedures. The collected samples were analyzed using RT-PCR. Prevalence of HPV infection was evaluated considering cytobrush and biopsy outcomes alone and combined. Correlation between HPV presence and sex, age, smoke, alcohol, kind of lichen planus, Hepatitis C virus, and involved mucosae was analyzed using chi-square test (significance at P < .05). Cohen's k coefficient was employed to compare brushing and biopsy.

RESULTS

Fifty-two patients affected by oral lichen planus were enrolled. Total HPV prevalence was 17%, when considering only the biopsy and the cytobrush the prevalence was 15% and 6%, respectively. None of the considered variables showed significant correlation with HPV (P > .05). The concordance between the two methods was "fair" (k = .305).

CONCLUSIONS

The biopsy appears more reliable than cytobrush to detect HPV in course of oral lichen planus. No statistical correlation emerged with the analyzed variables. The most frequently detected genotypes were HPV 6 and 11, while only two cases presented with HPV 16 and 53, known as human oncogenic.

Effect of Endometrial Sampling Procedures on Subsequent Pregnancy Rate of Cattle

Endometrial infections are a common cause of reproductive loss in cattle. Accurate diagnosis is important to reduce the economic losses caused by endometritis. A range of sampling procedures have been developed which enable collection of endometrial tissue or luminal cells or uterine fluid. However, as these are all invasive procedures, there is a risk that sampling around the time of breeding may adversely affect subsequent pregnancy rate. This systematic review compared the pregnancy rates (PR) of cattle which underwent uterine lavage (UL), cotton swab (CS), cytobrush (CB), cytotape (CT), or endometrial biopsy (EB) sampling procedures with those that were not sampled. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) protocol, relevant databases, including Pubmed, Web of Science, CAB Abstracts, VetMed Resource-Ruminants, and Scopus, were searched. The outcome measured was the pregnancy rate after the collection of endometrial sample(s). Seven studies, involving a total of 3693 cows, fulfilled the inclusion criteria for the systematic review and allowed the comparison of PR between sampled (n = 1254) and non-sampled cows (n = 2409). The results of the systematic review showed that endometrial sampling procedures can be performed before breeding or shortly after insemination without adversely affecting pregnancy rates in cattle. However, further studies are needed to validate this information.

Clinical trials optimizing investigator and self-collection of buccal cells for RNA yield

OBJECTIVE

Buccal cells are an ideal surrogate tissue for studying biologic effects of carcinogens or drugs, however inherent fragility and salivary RNAses limit RNA yield. We conducted healthy volunteer trials to optimize collection conditions.

METHODS

We conducted: (a) a single-arm crossover study evaluating four test conditions on RNA yield by buccal cytobrush; (b) a single-arm prospective study evaluating RNA yield by investigator vs self-collection.

RESULTS

Antecedent toothbrushing, time of day, and number of cytobrush strokes did not significantly impact RNA yield. RNA yield was doubled by using 2 vs 1 cytobrush per buccal surface (P = .0054). Self-collection of buccal cells for RNA was feasible; 36 of 50 (72%) samples passed quality control.

CONCLUSION

RNA yield was doubled by using two cytobrushes per buccal surface. Healthy volunteers can self-collect sufficient buccal RNA for gene expression studies. Techniques from these pragmatic trials could enhance availability of a limited tissue for serial biomarker measurements.

LEVEL OF EVIDENCE

1b-Prognosis Study (Individual prospective cohort study).

What sampling device is the most appropriate for vaginal vault cytology in gynaecological cancer follow up?

BACKGROUND

In women with cancer-related hysterectomy, the vaginal vault cytology has a low efficacy - when performed by conventional methods - for the early detection of vaginal recurrence. The amount of exfoliated cells collected is generally low because of atrophy, and the vaginal vault corners can be so narrow that the commonly used Ayres spatula cannot often penetrate deeply into them. This prospective study aimed at identifying the advantages obtained in specimens collection using the cytobrush, as compared to the Ayres's spatula. PATIENTS AND METHODS.: 141 gynaecologic cancer patients were studied to compare samplings collected with Ayre's spatula or with cytobrush. In a pilot setting of 15 patients, vaginal cytology samples obtained by both Ayre's spatula and cytobrush were placed at the opposite sites of a single slide for quali-quantitative evaluation. Thereafter, the remaining 126 consecutive women were assigned to either group A (spatula) or B (cytobrush) according to the order of entry. The same gynaecologist performed all the procedures.

RESULTS

In all 15 pilot cases, the cytobrush seemed to collect a higher quantity of material. The comparative analysis of the two complete groups indicated that the cytobrush technique was more effective than the spatula one. The odds ratio (OR) for an optimal cytology using the cytobrush was 2.8 (95% confidence interval -C.I. 1.3-6.2; chi-square test, p=0.008).

CONCLUSIONS

Vaginal vault cytology with cytobrush turned out to better perform than the traditional Ayre's spatula to obtain an adequate sampling in gynecological cancer patients.

Endometrial Cytology During the Different Phases of the Estrous Cycle in Jennies: New Evidences

Since in the mare and other animal species such as bitches and cats, the endometrial cell pattern varies depending on the phase of the estrous cycle, the aim of this study was to describe and quantify the endometrial cytological (EC) findings in cycling jennies. EC of eight nonpregnant jennies by cytobrush (CB) at diestrus (day 1 and day 14) and estrous (day 21) were evaluated. All slides were stained with Wright´s stain and microscopically examined at both 400× and 1000× magnification. Seven high-power fields (400×) were assessed in each smear and the endometrial epithelial cells and neutrophils (PMNs) were counted. Endometrial epithelial cells were classified as intact, distorted or fragmented and, on the basis of the presence of dense groups, in monolayer or single clusters. Cytoplasmic characteristics, such as vacuolation or streaming and size, form, position of nuclear characteristics, including karyorrhexis, were recorded. Background aspect, as clear, proteinaceous, or debris, was also considered. In general, sampling by CB provided a yield of cells and clumped endometrial epithelial cells in many smears, being more abundant in estrus than early and late diestrus. Individual endometrial epithelial cells, during estrous, presented a columnar morphology, ciliated or not ciliated and basal nuclei. During diestrus phase, endometrial epithelial cells presented a more cuboidal ciliated or not ciliated morphology. Moderate amount of proteinacious material and red blood cells (RBC) was also observed. Non variation in the percentage of PMNs during diestrus was obtained, but lower and segmented PMNs in CB smears were shown in estrous. This study provides new insights on the physiological changes of endometrial epithelial cells in cycling jennies during the estrus cycle. The CB technique represents a suitable and adequate method for endometrial evaluation, taking into account cytological and/or cytopathological purposes also in jennies.

Optimization of processing female genital tissue samples for lymphocyte analysis by flow cytometry

PROBLEM

A variety of methods have been used to process cervical cytobrush and genital tissue for flow cytometric evaluation of immune cell populations. We sought to optimize genital tract specimen processing and to determine if blood could be used as a model for assessment of tissue processing methods.

METHOD OF STUDY

Cervical cytobrushes, PBMCs, and genital tissue samples (cervical and endometrial biopsies) were subjected to varying processing conditions to characterize the effects on cell yields, lymphocyte viability, and surface receptors. We exposed PBMC and tissue specimens to varied collagenase types, concentrations, and exposure durations and cytobrushes to immediate vs delayed processing with/without vortexing.

RESULTS

PBMCs and tissues exposed to varying enzymatic digestion conditions demonstrated stability of some cell surface receptors, including CD3⁺ , CD4⁺ , and CD8⁺ , while others, including CCR6⁺ , were cleaved when exposed to any concentration of collagenase B, or ≥0.25 mg/mL of collagenase D. We observed increased CD69 expression (marker of cell activation) after exposure to collagenase B. Neither a 2-hour delay in cytobrush processing nor vortexing at a setting of 50% for 30 seconds had significant impacts on viability or quantities of genital immune cells of interest.

CONCLUSION

Although tissue digestion with collagenase D was sufficient to recover and analyze cells from endometrial biopsy specimens, cervical biopsy specimens required a limited exposure to collagenase B at 1 mg/mL to optimize cell yield and viability for cytometric analysis. PBMCs can be used as a model to assess the impact of tissue processing on co-receptor expression and to optimize methods prior to study implementation.

Papanicolaou test collection with the Papette brush or the spatula with cytobrush: A pragmatic study

BACKGROUND

Cotesting with the Papanicolaou (Pap) and human papillomavirus tests detects most precancerous and cancerous lesions and increases the sensitivity for detecting high-grade precancerous and invasive cervical cancers compared with human papillomavirus testing alone.

OBJECTIVE

To compare the use of the Papette brush (hereafter Papette) to the traditional spatula with endocervical brush (cytobrush) for cervical cancer screening.

DESIGN

Pragmatic observational study.

METHODS

Adult women aged 21-64 years who were eligible for a Papanicolaou test at a Midwest Community Internal Medicine practice underwent cervical cancer screening using the Papette or spatula with cytobrush from 18 August 2021 through 1 February 2022. Cluster sampling was used across the practice. Pathology reports were then analyzed to compare the number of satisfactory versus unsatisfactory results between the two collection techniques.

RESULTS

We collected results for 756 Pap tests. The test results were satisfactory with the Papette 93.8% of the time compared with 93.0% for the spatula with cytobrush.

CONCLUSION

The Papette is not inferior to a spatula with cytobrush as a collection method for Pap tests.

Machine learning to identify endometrial biomarkers predictive of pregnancy success following artificial insemination in dairy cows†

The objective was to identify a set of genes whose transcript abundance is predictive of a cow's ability to become pregnant following artificial insemination. Endometrial epithelial cells from the uterine body were collected for RNA sequencing using the cytobrush method from 193 first-service Holstein cows at estrus prior to artificial insemination (day 0). A group of 253 first-service cows not used for cytobrush collection were controls. There was no effect of cytobrush collection on pregnancy outcomes at day 30 or 70 or on pregnancy loss between days 30 and 70. There were 2 upregulated and 214 downregulated genes (false discovery rate < 0.05, absolute fold change >2-fold) for cows pregnant at day 30 versus those that were not pregnant. Functional terms overrepresented in the downregulated genes included those related to immune and inflammatory responses. Machine learning for fertility biomarkers with the R package BORUTA resulted in identification of 57 biomarkers that predicted pregnancy outcome at day 30 with an average accuracy of 77%. Thus, machine learning can identify predictive biomarkers of pregnancy in endometrium with high accuracy. Moreover, sampling of endometrial epithelium using the cytobrush can help understand functional characteristics of the endometrium at artificial insemination without compromising cow fertility. Functional characteristics of the genes comprising the set of biomarkers is indicative that a major determinant of cow fertility, at least for first insemination after calving, is immune status of the uterus, which, in turn, is likely to reflect the previous history of uterine disease.

Exfoliative Endometrial Cytology in Embryo Donor Cows-Comparison of Sampling Localizations for the Diagnosis of Subclinical Endometritis

Subclinical endometritis has a major effect on the reproductive performance of dairy cows and also on the success of embryo collection. Thus it is important to minimize the number of false-negative diagnoses. In order to evaluate the question of whether or not a single cytobrush sample is representative of the whole endometrium, 53 German Holstein embryo donor cows in the northwest of Germany were examined via the cytobrush method at three different localizations of the uterus: the uterine body about 0.5 cm cranial of the cervical canal and both uterine horns about 1.5 cm cranial of the bifurcation. Although the mean percentage of polymorphonuclear neutrophils at the three locations is not significantly different (p = 0.64), the individual variations lead to the conclusion that more than one sample of the endometrium should be taken into account when diagnosing subclinical endometritis in embryo donor cows.