Characterization of immune infiltrate along the leading edge of differentiated thyroid cancer.

BACKGROUND: While the impact of tumor-immune infiltrate has been reported on differentiated thyroid cancer behavior (DTC), the expression of immune checkpoints [programmed cell death protein 1 (PD-1) and its ligand (PD-L1)] alone has not been able to predict response to immunotherapies. We aimed to identify tumor-infiltrating immune cells and checkpoints associated with DTC. METHODS: We performed multiplex immunofluorescence on de-paraffinized thyroid tissue collected at thyroidectomy from 17 adults with DTC to characterize the tumor immune microenvironment for leukocytes (CD45+), T cells (CD3+), T regulatory cells (Tregs) (CD3+FOXP3+), CD4+ T cells (CD3+CD4+), CD8+ T cells (CD3+CD8+), macrophages (CD68+), M2 macrophages (CD68+CD163+), M1 Macrophages (CD68+iNOS+) and immune checkpoints PD-1 and PD-L1. We compared the mean percentage expression of immune markers between tumor and adjacent thyroid tissue from the same patient by paired t-test and performed spatial analysis along the tumor's leading edge. RESULTS: Immune checkpoints PD-1 and PD-L1 showed a significant increase in expression intratumorally as compared to adjacent thyroid tissue (p<0.05). A higher trend for M2 macrophages was observed intratumorally compared to adjacent tissue. Along the leading edge, PD-L1 expression correlated negatively with CD45 and positively with CD163 intratumorally. On exploratory analysis, there was a non-significant trend for higher FOXP3 but less CD8 and iNOS expression in tumor from DTC with (n=3) versus without distant metastases (n=14). There was a non-significant trend for higher CD58 and iNOS expression in DTC with (n=7) than without thyroiditis (n=10). CONCLUSIONS: Higher tumoral PD-1 and PD-L1 expression indicate their role in DTC occurrence. A trend for more Tregs and M2 macrophages but less M1 macrophages intratumorally in patients with distant metastatic DTC, suggests their potential role as prognostic biomarkers. Future studies with larger sample sizes are needed to compare various clinicopathologic severities to harness tumor microenvironment for cancer prognostication and therapy.

Relaxin-2 is a novel biomarker for differentiated thyroid carcinoma in humans.

Relaxin's role in differentiated thyroid cancer (DTC) has been suggested but its characterization in a large clinical sample remains limited. We performed immunohistochemistry for relaxin-2 (RLN2), CD68 (total macrophages), CD163 (M2 macrophages) on tissue microarrays from 181 subjects with non-distant metastatic DTC, and 185 subjects with benign thyroid tissue. Mean pixels/area for each marker was compared between tumor and adjacent tissue via paired-t test and between DTC and benign subjects via t-test assuming unequal variances. RNA qPCR was performed for expression of RLN2, RLN1, and RXFP1 in cell lines. Amongst 181 cases, the mean age was 46 years, 75 % were females. Tumoral tissue amongst the DTC cases demonstrated higher mean expression of RLN2 (53.04 vs. 9.79; p < 0.0001) compared to tumor-adjacent tissue. DTC tissue also demonstrated higher mean expression of CD68 (14.46 vs. 4.79; p < 0.0001), and CD163 (23.13 vs. -0.73; p < 0.0001) than benign thyroid. These markers did not differ between tumor-adjacent and benign thyroid tissue groups; and amongst cases, did not differ by demographic or clinicopathologic features. RLN1 and RXFP1 expression was detected in a minority of the cell lines, while RLN2 was expressed by 6/7 cell lines. In conclusion, widespread RLN2 expression in DTC tissue and most cell lines demonstrates that RLN2 acts in a paracrine manner, and that RLN1 and RXFP1 are probably not involved in thyroid cancer cell signaling. RLN2 is a biomarker for thyroid carcinogenesis, being associated with but not secreted by immunosuppressive macrophages. These findings will guide further investigations for therapeutic avenues against thyroid cancer.

Bioactive metabolites of OMEGA-6 and OMEGA-3 fatty acids are associated with inflammatory cytokine concentrations in maternal and infant plasma at the time of delivery.

BACKGROUND & AIMS: Inflammation is necessary for a healthy pregnancy. However, unregulated or excessive inflammation during pregnancy is associated with severe maternal and infant morbidities, such as pre-eclampsia, abnormal infant neurodevelopment, or preterm birth. Inflammation is regulated in part by the bioactive metabolites of omega-6 (n-6) and omega-3 (n-3) fatty acids (FAs). N-6 FAs have been shown to promote pro-inflammatory cytokine environments in adults, while n-3 FAs have been shown to contribute to the resolution of inflammation; however, how these metabolites affect maternal and infant inflammation is still uncertain. The objective of this study was to predict the influence of n-6 and n-3 FA metabolites on inflammatory biomarkers in maternal and umbilical cord plasma at the time of delivery. METHODS: Inflammatory biomarkers (IL-1ß, IL-2, IL-6, IL-8, IL-10, and TNFα) for maternal and umbilical cord plasma samples in 39 maternal-infant dyads were analyzed via multi-analyte bead array. Metabolites of n-6 FAs (arachidonic acid and linoleic acid) and n-3 FAs (eicosapentaenoic acid and docosahexaenoic acid) were assayed via liquid chromatography-mass spectrometry. Linear regression models assessed relationships between maternal and infant inflammatory markers and metabolite plasma concentrations. RESULTS: Increased plasma concentrations of maternal n-6 metabolites were predictive of elevated pro-inflammatory cytokine concentrations in mothers; similarly, higher plasma concentrations of umbilical cord n-6 FA metabolites were predictive of elevated pro-inflammatory cytokine concentrations in infants. Higher plasma concentrations of maternal n-6 FA metabolites were also predictive of elevated pro-inflammatory cytokines in infants, suggesting that maternal n-6 FA status has an intergenerational impact on the inflammatory status of the infant. In contrast, maternal and cord plasma concentrations of n-3 FA metabolites had a mixed effect on inflammatory status in mothers and infants, which may be due to the inadequate maternal dietary intake of n-3 FAs in our study population. CONCLUSIONS: Our results reveal that maternal FA status may have an intergenerational impact on the inflammatory status of the infant. Additional research is needed to identify how dietary interventions that modify maternal FA intake prior to or during pregnancy may impact maternal and infant inflammatory status and associated long-term health outcomes.

Diagnosis of primary vitreoretinal lymphoma masquerading infectious retinitis by retinal biopsy.

PURPOSE: To report a case of primary vitreoretinal lymphoma masquerading as infectious retinitis that was diagnosed via a retinal biopsy. OBSERVATIONS: A 72-year-old female patient was referred to our ophthalmology clinic for evaluation of retinitis and vasculitis in the right eye (OD). On examination, best-corrected visual acuities (BCVAs) were hand motions OD and 20/20 in the left eye (OS). Fundus examination revealed optic disc edema and diffuse retinal whitening superior to the superotemporal arcade OD. Given the high suspicion of infectious retinitis, the patient was treated with intravitreal foscarnet, systemic acyclovir, and oral prednisone and underwent a comprehensive uveitis workup, which was unremarkable for viral and autoimmune entities. Given the patient's history of diffuse large B cell lymphoma with cutaneous involvement, vitreoretinal lymphoma was suspected, prompting pars plana vitrectomy with a retinal biopsy. Biopsy and immunohistochemistry results were consistent with B-cell lymphoma, and the patient was treated with high-dose methotrexate and rituximab. At 5-month follow-up, BCVAs were hand motions OD and 20/30 OS, and fundus examination demonstrated disc edema with resolution of retinal whitening OD. She responded well to the treatment with regression of vitreoretinal lymphoma on examination and is being monitored closely for lymphoma recurrence. CONCLUSIONS AND IMPORTANCE: Although uncommon, patients with vitreoretinal lymphoma may masquerade as infectious retinitis, and vitreoretinal lymphoma should be suspected when refractory to antiviral therapy and in the setting of a negative workup for viral etiologies. Vitrectomy with retinal biopsy may be considered to aid the diagnosis of vitreoretinal lymphoma although careful consideration of the risks and benefits is warranted.

Editorial: Optimizing Schools of Cytology: Discussions from the 2022 ASC/IAC Cytology Education Symposium, North American Strategies, and European Symbiosis.

This report highlights information and outcomes from the November 2022 ASC/IAC joint Cytology Education Symposium, an annual conference organized by the Cytology Programs Review Committee. The manuscript provides information on shared educational opportunities and practices for cytology students and other learners in anatomic pathology, discusses recruitment strategies for schools of cytology, conveys teaching resources, introduces perspectives on virtual microscopy and online learning, and transmits information about wellness of students in schools of cytology.

Excellent Response to Therapy Occurs for Most Patients With Thyroid Cancer Treated With Lobectomy.

INTRODUCTION: American Thyroid Association (ATA) Guidelines for Management of Thyroid Nodules and Thyroid Cancer indicate that thyroid lobectomy (TL) or total thyroidectomy (TT) are appropriate surgery for low- and intermediate-risk well-differentiated thyroid carcinoma. We sought to determine outcomes of TL or TT by ATA response to therapy (RTT) classification. METHODS: This is a single-institution retrospective cohort study of adults with unilateral suspicious or malignant thyroid nodules under 4 cm from January 2016 through December 2021. Our primary outcome was ATA RTT. RESULTS: During the study period, 118 met inclusion criteria: 37 (31%) underwent TL and 81 (69%) TT. Of the TL patients, 7 (19%) underwent completion thyroidectomy. Response to therapy (RTT) was similar with TT versus TL: excellent response 56 (69%) versus 30 (81%), indeterminate response 20 (25%) versus 5 (14%), and biochemically incomplete response 5 (6%) versus 2 (5%), P = 0.20. There were no differences between the groups for age, sex, race or ethnicity, tumor size, histologic type, or complications. Thyroidectomy (TT) was associated with multiple nodules 47% versus 22% for TL (P = 0.009), bilateral nodules 43% versus 16% (P = 0.004), central neck lymph nodes removed median 3 (interquartile range [IQR] 1-8) versus 0 (IQR 0-2) P < 0.001, lymph node metastases median 0 (IQR 0-1) versus 0 (0-0) P = 0.02. Median follow-up was 32.5 mo (IQR 17-56 mo) and was similar between the groups. CONCLUSIONS: Patients with TL for well-differentiated thyroid carcinoma without high-risk features have an RTT similar to patients undergoing TT. In this cohort, 81% of patients treated with TL have not required additional intervention.

Optimizing schools of cytology: Discussions from the 2022 ASC/IAC Cytology Education Symposium, North American Strategies, and European Symbiosis.

This report highlights information and outcomes from the November 2022 ASC/IAC joint Cytology Education Symposium, an annual conference organized by the Cytology Programs Review Committee. The manuscript provides information on shared educational opportunities and practices for cytology students and other learners in anatomic pathology, discusses recruitment strategies for schools of cytology, conveys teaching resources, introduces perspectives on virtual microscopy and online learning, and transmits information about wellness of students in schools of cytology.

Thoracic SMARCA4-Deficient Undifferentiated Tumors With Unusual Presentations: A Case Series.

CONTEXT: Thoracic SMARCA4-deficient undifferentiated tumor (SMARCA4-UT) is a recently described aggressive neoplasm of young smokers defined by SMARCA4 inactivating mutations and characterized by cells with rhabdoid morphology, high mitotic activity, and abundant necrosis. OBJECTIVE: Describe and compare 3 unusual presentations of SMARCA4-UT in older adults, including one presenting as a metastatic lesion mimicking a primary bone sarcoma. Discuss the molecular characteristics of SMARCA4-UT and their relationship to nonsmall-cell lung carcinomas with SMARCA4. DESIGN: Three patients with SMARCA4-UTs were identified utilizing a natural language search in CoPath. hematoxylin and eosin sections from all patients as well as Papanicolaou-stained slides and Diff-Quik-stained slides for the first patient were examined. A broad range of immunostains, including BRG1/SMARCA4, were evaluated. Molecular testing was performed via next-generation sequencing. RESULTS: The 3 patients were aged 58, 70, and 70 years. All had a significant smoking history. The first patient presented with an iliac bone mass and mediastinal lymphadenopathy, the second with mediastinal adenopathy, and the third with a paratracheal mass. All 3 tumors showed a diffuse proliferation of pleomorphic, rhabdoid cells with high mitotic activity and tumor necrosis. SMARCA4 was lost in all 3 tumors by immunohistochemistry. Molecular testing revealed SMARCA4 alterations in the first 2. CONCLUSIONS: Thoracic SMARCA4-UT should be considered in the differential diagnosis of pleomorphic rhabdoid tumors in older adults with a smoking history. Although most present as lung and/or mediastinal masses, they may occasionally present as a metastasis and mimic an undifferentiated sarcoma, representing a potential diagnostic pitfall.

Disseminated Aspergillosis in a Patient With Neurosarcoidosis: Persistent Contrast Enhancement in CNS Despite Prolonged Antifungal Treatment: A Case Report.

A 56-year-old Caucasian man was diagnosed with definite neurosarcoidosis after he presented with progressive bilateral lower extremity weakness and dysesthesia. He was started on a combination immunosuppressant regimen of dexamethasone, methotrexate and infliximab. Two months into treatment with immunosuppressants, he developed devastating disseminated aspergillosis which clinically stabilized with aggressive antifungal treatment however had a protracted radiological course despite prolonged anti-fungal treatment for over two years. Interestingly, he remained in remission from neurosarcoidosis off immunosuppression during the same period. This case emphasizes need for vigilance for fungal infections in patients treated with combination immunosuppressive therapy particularly TNF-α inhibitors such as infliximab.

Something Smells Fishy: How Lipid Mediators Impact the Maternal-Fetal Interface and Neonatal Development.

Normal pregnancy relies on inflammation for implantation, placentation, and parturition, but uncontrolled inflammation can lead to poor maternal and infant outcomes. Maternal diet is one modifiable factor that can impact inflammation. Omega-3 and -6 fatty acids obtained through the diet are metabolized into bioactive compounds that effect inflammation. Recent evidence has shown that the downstream products of omega-3 and -6 fatty acids may influence physiology during pregnancy. In this review, the current knowledge relating to omega-3 and omega-6 metabolites during pregnancy will be summarized.

Successful integration of thyroid cytopathology and surgical pathology education in an E-module format.

Context: The shift to digital learning in medicine is well underway and in fact spurred by the COVID-19 pandemic. The didactic portion of our institution's cytotechnology (CT) education program is online and delivered to learners across the nation. With CT education elevating to the master's degree level, there is a need to expand cytologic correlation with surgical resection specimens. We also wanted to afford pathology residents the same. Methods: We developed an online cytologic-histologic correlation digital learning module (e-module) addressing thyroid fine needle aspirations (FNAs) and surgical thyroidectomy specimens which was administered as part of coursework in the CT education and pathology residency programs. The module was 35 min long and consisted of guided narration with both formative and summative interactive quizzes. After completion of the module, participants were invited to fill a brief survey comprised of multiple choice, Likert, and free response questions. This study was approved by the institutional review board. Results: The 29 respondents were comprised of 22 CT students and 7 residents. CT students had minimal experience thyroid pathology prior to the module; residents were mixed. Twenty-three (79.3%) ranked the highest tiers for learning cytopathology through this module, 24 (82.8%) for learning thyroid surgical pathology, and 25 (86.2%) for cytologic-histologic correlation. All respondents stated they would like similar activities in the future. Conclusions: Teaching cytology-histology correlation for thyroid in an electronic format was effective and well-received by participants. There is a demand for these activities among current learners, suggesting that expanding the available repertoire will be beneficial.

IL-22 regulates inflammatory responses to agricultural dust-induced airway inflammation.

IL-22 is a unique cytokine that is upregulated in many chronic inflammatory diseases, including asthma, and modulates tissue responses during inflammation. However, the role of IL-22 in the resolution of inflammation and how this contributes to lung repair processes are largely unknown. Here, we tested the hypothesis that IL-22 signaling is critical in inflammation resolution after repetitive exposure to agricultural dust. Using an established mouse model of organic dust extract-induced lung inflammation, we found that IL-22 knockout mice have an enhanced response to agricultural dust as evidenced by an exacerbated increase in infiltrating immune cells and lung pathology as compared to wild-type controls. We further identified that, in response to dust, IL-22 is expressed in airway epithelium and in Ym1+ macrophages found within the parenchyma in response to dust. The increase in IL-22 expression was accompanied by increases in IL-22 receptor IL-22R1 within the lung epithelium. In addition, we found that alveolar macrophages in vivo as well as THP-1 cells in vitro express IL-22, and this expression is modulated by dust exposure. Furthermore, subcellular localization of IL-22 appears to be in the Golgi of resting THP1 human monocytes, and treatment with dust extracts is associated with IL-22 release into the cytosolic compartment from the Golgi reservoirs during dust extract exposure. Taken together, we have identified a significant role for macrophage-mediated IL-22 signaling that is activated in dust-induced lung inflammation in mice.

Omega-6 and Omega-3 Fatty Acid-Derived Oxylipins from the Lipoxygenase Pathway in Maternal and Umbilical Cord Plasma at Delivery and Their Relationship with Infant Growth.

Omega-3 and omega-6 fatty acids are important for neonatal development and health. One mechanism by which omega-3 and omega-6 fatty acids exert their effects is through their metabolism into oxylipins and specialized pro-resolving mediators. However, the influence of oxylipins on fetal growth is not well understood. Therefore, the objective of this study was to identify oxylipins present in maternal and umbilical cord plasma and investigate their relationship with infant growth. Liquid chromatography-tandem mass spectrometry was used to quantify oxylipin levels in plasma collected at the time of delivery. Spearman's correlations highlighted significant correlations between metabolite levels and infant growth. They were then adjusted for maternal obesity (normal body mass index (BMI: ≤30 kg/m2) vs. obese BMI (>30 kg/m2) and smoking status (never vs. current/former smoker) using linear regression modeling. A p-value < 0.05 was considered statistically significant. Our study demonstrated a diverse panel of oxylipins from the lipoxygenase pathway present at the time of delivery. In addition, both omega-3 and omega-6 oxylipins demonstrated potential influences on the birth length and weight percentiles. The oxylipins present during pregnancy may influence fetal growth and development, suggesting potential metabolites to be used as biomarkers for infant outcomes.

QuPath Digital Immunohistochemical Analysis of Placental Tissue.

BACKGROUND: QuPath is an open-source digital image analyzer notable for its user-friendly design, cross-platform compatibility, and customizable functionality. Since it was first released in 2016, at least 624 publications have reported its use, and it has been applied in a wide spectrum of settings. However, there are currently limited reports of its use in placental tissue. Here, we present the use of QuPath to quantify staining of G-protein coupled receptor 18 (GPR18), the receptor for the pro-resolving lipid mediator Resolvin D2, in placental tissue. METHODS: Whole slide images of vascular smooth muscle (VSM) and extravillous trophoblast (EVT) cells stained for GPR18 were annotated for areas of interest. Visual scoring was performed on these images by trained and in-training pathologists, while QuPath scoring was performed with the methodology described herein. RESULTS: Bland-Altman analyses showed that, for the VSM category, the two methods were comparable across all staining levels. For EVT cells, the high-intensity staining level was comparable across methods, but the medium and low staining levels were not comparable. CONCLUSIONS: Digital image analysis programs offer great potential to revolutionize pathology practice and research by increasing accuracy and decreasing the time and cost of analysis. Careful study is needed to optimize this methodology further.

Comparison of Afirma GEC and GSC to Nodules Without Molecular Testing in Cytologically Indeterminate Thyroid Nodules.

BACKGROUND: Analysis of cytologically indeterminate thyroid nodules with Afirma Gene Expression Classifier (GEC) and Genomic Sequencing Classifier (GSC) can reduce surgical rate and increase malignancy rate of surgically resected indeterminate nodules. METHODS: Retrospective cohort analysis of all adults with cytologically indeterminate thyroid nodules from January 2013 through December 2019. We compared surgical and malignancy rates of those without molecular testing to those with GEC or GSC, analyzed test performance between GEC and GSC, and identified variables associated with molecular testing. RESULTS: 468 indeterminate thyroid nodules were included. No molecular testing was performed in 273, 71 had GEC, and 124 had GSC testing. Surgical rate was 68% in the group without molecular testing, 59% in GEC, and 40% in GSC. Malignancy rate was 20% with no molecular testing, 22% in GEC, and 39% in GSC (P = 0.022). GEC benign call rate (BCR) was 46%; sensitivity, 100%; specificity, 61%; and positive predictive value (PPV), 28%. GSC BCR was 60%; sensitivity, 94%; specificity, 76%; and PPV, 41%. Those with no molecular testing had larger nodule size, preoperative growth of nodules, and constrictive symptoms and those who underwent surgery in the no molecular testing group had higher body mass index, constrictive symptoms, higher Thyroid Imaging Reporting and Data System and Bethesda classifications. Type of provider was also associated with the decision to undergo surgery. CONCLUSION: Implementation of GEC showed no effect on surgical or malignancy rate, but GSC resulted in significantly lower surgical and higher malignancy rates. This study provides insight into the factors that affect the real-world use of these molecular markers preoperatively in indeterminate thyroid nodules.

Intrauterine Transfer of Polyunsaturated Fatty Acids in Mother-Infant Dyads as Analyzed at Time of Delivery.

Polyunsaturated fatty acids (PUFAs) are essential for fetal development, and intrauterine transfer is the only supply of PUFAs to the fetus. The prevailing theory of gestational nutrient transfer is that certain nutrients (including PUFAs) may have prioritized transport across the placenta. Numerous studies have identified correlations between maternal and infant fatty acid concentrations; however, little is known about what role maternal PUFA status may play in differential intrauterine nutrient transfer. Twenty mother-infant dyads were enrolled at delivery for collection of maternal and umbilical cord blood, and placental tissue samples. Plasma concentrations of PUFAs were assessed using gas chromatography (GC-FID). Intrauterine transfer percentages for each fatty acid were calculated as follows: ((cord blood fatty acid level/maternal blood fatty acid level) × 100). Kruskal-Wallis tests were used to compare transfer percentages between maternal fatty acid tertile groups. A p-value < 0.05 was considered significant. There were statistically significant differences in intrauterine transfer percentages of arachidonic acid (AA) (64% vs. 65% vs. 45%, p = 0.02), eicosapentaenoic acid (EPA) (41% vs. 19% vs. 17%, p = 0.03), and total fatty acids (TFA) (27% vs. 26% vs. 20%, p = 0.05) between maternal plasma fatty acid tertiles. Intrauterine transfer percentages of AA, EPA, and TFA were highest in the lowest tertile of respective maternal fatty acid concentration. These findings may indicate that fatty acid transfer to the fetus is prioritized during gestation even during periods of maternal nutritional inadequacy.

Concentrations of fat-soluble nutrients and blood inflammatory compounds in mother-infant dyads at birth.

BACKGROUND: Perinatal inflammation adversely affects health. Therefore, aims of this IRB-approved study are: (1) compare inflammatory compounds within and between maternal and umbilical cord blood samples at the time of delivery, (2) assess relationships between inflammatory compounds in maternal and cord blood with birth characteristics/outcomes, and (3) assess relationships between blood and placental fat-soluble nutrients with blood levels of individual inflammatory compounds. METHODS: Mother-infant dyads were enrolled (n = 152) for collection of birth data and biological samples of maternal blood, umbilical cord blood, and placental tissue. Nutrient levels included: lutein + zeaxanthin; lycopene; α-, ß-carotene; ß-cryptoxanthin; retinol; α-, γ-, δ-tocopherol. Inflammatory compounds included: tumor necrosis factor-α, superoxide dismutase, interleukins (IL) 1ß, 2, 6, 8, 10. RESULTS: Median inflammatory compound levels were 1.2-2.3 times higher in cord vs. maternal blood, except IL2 (1.3 times lower). Multiple significant correlations existed between maternal vs. infant inflammatory compounds (range of r = 0.22-0.48). While relationships existed with blood nutrient levels, the most significant were identified in placenta where all nutrients (except δ-tocopherol) exhibited relationships with inflammatory compounds. Relationships between anti-inflammatory nutrients and proinflammatory compounds were primarily inverse. CONCLUSION: Inflammation is strongly correlated between mother-infant dyads. Fat-soluble nutrients have relationships with inflammatory compounds, suggesting nutrition is a modifiable factor. IMPACT: Mother and newborn inflammation status are strongly interrelated. Levels of fat-soluble nutrients in blood, but especially placenta, are associated with blood levels of proinflammatory and anti-inflammatory compounds in both mother and newborn infant. As fat-soluble nutrient levels are associated with blood inflammatory compounds, nutrition is a modifiable factor to modulate inflammation and improve perinatal outcomes.

Fat-soluble nutrients and Omega-3 fatty acids as modifiable factors influencing preterm birth risk.

Preterm birth is a leading cause of child morbidity and mortality, so strategies to reduce early birth must remain a priority. One key approach to enhancing birth outcomes is improving maternal dietary intake. Therefore, the purpose of this review is to discuss mechanisms on perinatal status of fat-soluble nutrients (carotenoids, retinol, tocopherols) and omega-3 fatty acids and how they impact risk for preterm birth. Literature review demonstrates that maternal dietary intake and biological (blood and placental tissue) levels of fat-soluble nutrients during pregnancy may provide antioxidative, anti-inflammatory, and immunomodulatory health benefits. Omega-3 fatty acids also promote increased production of specialized pro-resolving mediators, subsequently mediating inflammation resolution. Combined effects of these nutrients support appropriate placental organogenesis and function. Consequently, fat-soluble nutrients and omega-3 fatty acids serve as strong influencers for preterm birth risk. As dietary intake remains a modifiable factor, future intervention would benefit from a focus on optimizing perinatal status of these specific nutrients.