Risk of adverse perinatal outcomes among women with clinical and subclinical histopathological chorioamnionitis.

Introduction: Histologic chorioamnionitis (HCA) is a placental inflammatory condition associated with adverse perinatal outcomes (APOs). This historical cohort study explores the risk of APOs in pregnant women with HCA and compares the impact of clinical chorioamnionitis (CCA) with subclinical chorioamnionitis (SCCA). Methodology: Placentas were evaluated by a perinatal pathologist tand all women with HCA were included. Two groups were integrated: (1) women with clinical chorioamnionitis (CCA) and (2) women with subclinical chorioamnionitis (SCCA). Additionally, we conducted a secondary analysis to compare the prevalence of APOs among stage 1, 2 and 3 of HCA and the risk of APOs between grades 1 and 2 of HCA. The APOs analyzed were preterm birth, stillbirth, neonatal weight < 1,500 g, neonatal sepsis. Relative risk with 95% confidence interval was calculated. Results: The study included 41 cases of CCA and 270 cases of SCCA. The mean gestational age at diagnosis and birth was 30.2 ± 5.4 weeks and 32.5 ± 5.1 weeks, for group 1 and 2, respectively. The study also found that women with HCA stage 3 and grade 2 had a higher prevalence and risk of adverse perinatal outcomes. Discussion: The findings of this study suggest the importance of placental histological study to excluded SCCA, which represents a significant risk to both maternal and neonatal health, contributing to high morbidity and mortality.

Disturbances in the IgG Antibody Profile in HIV-Exposed Uninfected Infants Associated with Maternal Factors.

Over the last 20 years, the incidence of vertical HIV transmission has decreased from 25%-42% to less than 1%. Although there are no signs of infection, the health of HIV-exposed uninfected (HEU) infants is notoriously affected during the first months of life, with opportunistic infections being the most common disease. Some studies have reported effects on the vertical transfer of antibodies, but little is known about the subclass distribution of these antibodies. We proposed to evaluate the total IgG concentration and its subclasses in HIV+ mothers and HEU pairs and to determine which maternal factors condition their levels. In this study, plasma from 69 HEU newborns, their mothers, and 71 control pairs was quantified via immunoassays for each IgG isotype. Furthermore, we followed the antibody profile of HEUs throughout the first year of life. We showed that mothers present an antibody profile characterized by high concentrations of IgG1 and IgG3 but reduced IgG2, and HEU infants are born with an IgG subclass profile similar to that of their maternal pair. Interestingly, this passively transferred profile could remain influenced even during their own antibody production in HEU infants, depending on maternal conditions such as CD4+ T-cell counts and maternal antiretroviral treatment. Our findings indicate that HEU infants exhibit an altered IgG subclass profile influenced by maternal factors, potentially contributing to their increased susceptibility to infections.

Síndrome inflamatorio de reconstitución inmunológica (SIRS) en la salud reproductiva / Immune reconstitution inflammatory syndrome (IRIS) in reproductive health

Resumen El embarazo es un proceso que genera grandes cambios inmunitarios en los cuales participan los linfocitos T con respuestas proinflamatorias (Th1/Th17) y antiinflamatorias (Th2/Treg), con la finalidad de mantener el óptimo estado y desarrollo fetal. En la infección por VIH estos ambientes inmunológicos son afectados directamente con el descenso de las células TCD4. El uso de antirretrovirales (ART) ha permitido que las mujeres que viven con VIH puedan disminuir de manera importante la posibilidad de infectar a sus productos con el virus. El embarazo, enfermedades autoinmunes y el uso de ART son factores conocidos para el desarrollo del síndrome inflamatorio de reconstitución inmunológica debido a la recuperación abrupta de la respuesta inmunitaria. En esta revisión describimos parte de estos cambios en el embarazo y puerperio sin patología añadida, además proponemos un posible comportamiento en los perfiles Th1/Th2 en mujeres que viven con VIH que reciben ART y cursan el primer año posparto.

Abstract Pregnancy is a process which generate great immunologic changes with participation of T lymphocytes with inflammatory (Th1/Th17) and anti-inflammatory response (Th2/Treg), with the purpose of maintain the optimum condition and fetal development. In HIV infection this immunological ambient are affected directly due the decrease of T CD4 cells. The use of antiretrovirals (ART) has allowed that women living with HIV can decrease the possibility to infect their newborns with the virus. The pregnancy, autoimmune diseases, and the use of ART are known factors for the progress of immune reconstitution inflammatory syndrome due to the abrupt recovery of immune response. In this review we describe some of these changes during the pregnancy and puerperium without any disease added, furthermore we propose a possible behavior of Th1/Th2 profile in women who live with HIV and receive ART during the first year of postpartum.

Psychological distress, anxiety, depression, stress level, and coping style in HIV-pregnant women in Mexico.

PURPOSE: To evaluate the presence of psychological distress (PD) and its association with the mental health and coping styles of pregnant women living with HIV (PWLWH). METHOD: An observational, cross-sectional descriptive study was performed. Seventy-three PWLWH were included. Patients responded to a psychometric battery for PD, depression, anxiety, stress, and coping style evaluation. The scales used in the study were: Goldberg's 30-item General Health Questionnaire (GHQ-30), State-Trait Anxiety Inventory (STAI), Zung Depression Self-Measurement Scale (ZDS), Nowack Stress Profile, Lazarus and Folkman's Coping Styles Questionnaire. RESULTS: PD was observed in 31.5% of the participants. PD-positive patients showed a higher probability of presenting traits of depression and anxiety and medium/high stress levels. Besides, they preferentially used emotion-focused coping styles. CONCLUSION: PD is associated with a higher probability of presenting anxiety and depression in PWLWH. Emotion-focused coping style could be a factor in decision-making associated with risk behaviors in PWLWH.

Regional moderate hyperthermia for mild-to-moderate COVID-19 (TherMoCoV study): a randomized controlled trial.

Background: To prevent COVID-19 progression, low-cost alternatives that are available to all patients are needed. Diverse forms of thermotherapy have been proposed to prevent progression to severe/critical COVID-19. Objective: The aim of this study is to evaluate the efficacy and safety of local thermotherapy to prevent disease progression in hospitalized adult patients with mild-to-moderate COVID-19. Methods: A multicenter, open-label, parallel-group, randomized, adaptive trial is used to evaluate the efficacy and safety of local thermotherapy to prevent disease progression in hospitalized adult patients with mild-to-moderate COVID-19. Eligible hospitalized adult patients with symptoms of COVID-19 with ≤5 days from symptom onset, meeting criteria for mild or moderate COVID-19, were randomly assigned to the intervention consisting of local thermotherapy via an electric heat pad in the thorax (target temperature range 39.5­42°C) continuously for 90 min, twice daily, for 5 days, or standard care. The main outcome was the proportion of patients who progressed to severe-to-critical COVID-19 or death. Patients were randomized in a 1:1 ratio through a centralized computer-generated sequence of minimization with a random component of 20%. Participants and medical staff were not blinded to the intervention. Results: One-hundred and five participants (thermotherapy n = 54, control n = 51) with a median age of 53 (IQR: 41­64) years were included for analysis after the early cessation of recruitment due to the closure of all temporal COVID-19 units (target sample size = 274). The primary outcome of disease progression occurred in 31.4% (16/51) of patients in the control group vs. 25.9% (14/54) of those receiving thermotherapy (risk difference = 5.5%; 95%CI: −11.8­22.7, p = 0.54). Thermotherapy was well tolerated with a median total duration of thermotherapy of 900 (IQR: 877.5­900) min. Seven (13.7%) patients in the control group and seven (12.9%) in the thermotherapy group had at least one AE (p = 0.9), none of which were causally attributed to the intervention. No statistically significant differences in serum cytokines (IL-1ß, IL-6, IL-8, IL-10, IL-17, and IFN-γ) were observed between day 5 and baseline among groups. Conclusion: Local thermotherapy was safe and well-tolerated. A non-statistically significant lower proportion of patients who experienced disease progression was found in the thermotherapy group compared to standard care. Local thermotherapy could be further studied as a strategy to prevent disease progression in ambulatory settings.Clinical Trial registration: www.clinicaltrials.gov, identifier: NCT04363541.

COVID-19 Infection in Pregnancy: PCR Cycle Thresholds, Placental Pathology, and Perinatal Outcomes.

(1) This study aimed to evaluate characteristics, perinatal outcomes, and placental pathology of pregnant women with or without SARS-CoV-2 infection in the context of maternal PCR cycle threshold (CT) values. (2) This was a retrospective case-control study in a third-level health center in Mexico City with universal screening by RT-qPCR. The association of COVID-19 manifestations, preeclampsia, and preterm birth with maternal variables and CT values were assessed by logistic regression models and decision trees. (3) Accordingly, 828 and 298 women had a negative and positive test, respectively. Of those positive, only 2.6% of them presented mild to moderate symptoms. Clinical characteristics between both groups of women were similar. No associations between CT values were found for maternal features, such as pre-gestational BMI, age, and symptomatology. A significantly higher percentage of placental fibrinoid was seen with women with low CTs (<25; p < 0.01). Regarding perinatal outcomes, preeclampsia was found to be significantly associated with symptomatology but not with risk factors or CT values (p < 0.01, aOR = 14.72). Moreover, 88.9% of women diagnosed with COVID-19 at <35 gestational weeks and symptomatic developed preeclampsia. (4) The data support strong guidance for pregnancies with SARS-CoV-2 infection, in particular preeclampsia and placental pathology, which need further investigation.

Impaired T helper cell responses in human immunodeficiency virus-exposed uninfected newborns.

INTRODUCTION: HIV-exposed uninfected (HEU) newborns suffer from higher risks of opportunistic infections during the first months of life compared to HIV-unexposed uninfected (HUU) newborns. Alterations in thymic mass, amounts of T helper (Th) cells, T-cell receptor diversity, and activation markers have been found in HEU newborns, suggesting alterations in T cell ontogeny and differentiation. However, little is known about the ability of these cells to produce specialized Th responses from CD4+ T cells. METHOD: To characterize the Th cell profile, we evaluated the frequency of Th1 (CD183+ CD194- CD196- /CXCR3+ CCR4- CCR6- ), Th2 (CD183- CD194+ CD196- /CXCR3- CCR4+ CCR6- ), Th17 (CD183- CD194+ CD196+ /CXCR3- CCR4+ CCR6+ ), and CD4+ CD25++ blood T-cell phenotypes in 50 HEU and 25 HUU newborns. Early activation markers on CD4+ T cells and the Th cytokine profile produced from mononuclear cells under polyclonal T cell stimulation were also studied. Additionally, we probed the ability of CD4+ T cells to differentiate into interferon (IFN)-γ-producing Th1 CD4+ T cells in vitro. RESULTS: Lower percentages of differentiated Th1 , Th2 , Th17, and CD4+ CD25++ T cells were found in blood from HEU newborns than in blood from HUU newborns. However, polyclonally stimulated Th cells showed a similar ability to express CD69 and CD279 but produced less secreted interleukin (IL)-2 and IL-4. Interestingly, under Th1 differentiation conditions, the percentages of CD4+ IFN-γ+ T cells and soluble IFN-γ were higher in HEU newborns than in HUU newborns. CONCLUSION: HEU neonates are born with reduced proportions of differentiated Th1 /Th2 /Th17 and CD4+ CD25++ T cells, but the intrinsic abilities of CD4+ T cells to acquire a Th1 profile are not affected by the adverse maternal milieu during development.

Prevalence, clinical features, and outcomes of SARS-CoV-2 infection in pregnant women with or without mild/moderate symptoms: Results from universal screening in a tertiary care center in Mexico City, Mexico.

The perinatal consequences of SARS-CoV-2 infection are still largely unknown. This study aimed to describe the features and outcomes of pregnant women with or without SARS-CoV-2 infection after the universal screening was established in a large tertiary care center admitting only obstetric related conditions without severe COVID-19 in Mexico City. This retrospective case-control study integrates data between April 22 and May 25, 2020, during active community transmission in Mexico, with one of the highest COVID-19 test positivity percentages worldwide. Only pregnant women and neonates with a SARS-CoV-2 result by quantitative RT-PCR were included in this study. Among 240 pregnant women, the prevalence of COVID-19 was 29% (95% CI, 24% to 35%); 86% of the patients were asymptomatic (95% CI, 76%-92%), nine women presented mild symptoms, and one patient moderate disease. No pregnancy baseline features or risk factors associated with severity of infection, including maternal age > 35 years, Body Mass Index >30 kg/m2, and pre-existing diseases, differed between positive and negative women. The median gestational age at admission for both groups was 38 weeks. All women were discharged at home without complications, and no maternal death was reported. The proportion of preeclampsia was higher in positive women than negative women (18%, 95% CI, 10%-29% vs. 9%, 95% CI, 5%-14%, P<0.05). No differences were found for other perinatal outcomes. SARS-CoV-2 test result was positive for nine infants of positive mothers detected within 24h of birth. An increased number of infected neonates were admitted to the NICU, compared to negative neonates (44% vs. 22%, P<0.05) and had a longer length of hospitalization (2 [2-18] days vs. 2 [2-3] days, P<0.001); these are potential proxies for illness severity. This report highlights the importance of COVID-19 detection at delivery in pregnant women living in high transmission areas.

Assessment of lamivudine, zidovudine, lopinavir, and ritonavir plasma levels in HIV-positive pregnant women: Drug monitoring application to improve patient safety.

Simultaneous therapeutic drug monitoring (TDM) of combination antiretroviral therapy (cART) is critical during pregnancy in order to improve clinical follow-up, monitor viral load, and patient adherence to treatment.A modified simple and fast ultra-high performance liquid chromatography coupled with tandem mass spectrometry and electrospray ionization (UPLC-ESI-MS/MS) method was developed and validated according to national and international guidelines for the simultaneous determination of lamivudine (LMV), zidovudine (ZDV), lopinavir (LPV), and ritonavir (RTV) concentrations in 100-µL plasma sample of Human Immunodeficiency Virus (HIV)-positive pregnant women. Protein precipitation using 0.1% formic acid in cold acetonitrile was used for sample preparation. The chromatographic separation was achieved with a run-time of 3.0 minutes and 3-µL injection on an ethylene bridged hybrid C18 column (2.1 µm × 50 mm, 1.7 µm), under gradient conditions using acetonitrile and formic acid (0.1%).The chromatographic method was used to analyze 10 plasma samples from 8 HIV pregnant women as a clinical patient routinely follow-up by applying TDM criteria.The protonated precursor/product ion transitions for LMV (230.18/112.08), ZDV (268.22/127.10), LPV (629.55/447.35), and RTV (721.50/296.20) were recorded in multiple-reaction-monitoring (MRM) mode. The calibration curve was linear in the range of 50-3,000, 75-4,500, 250-15,000, and 25-1,500-ng/mL for LMV, ZDV, LPV, and RTV, respectively. The range of accuracy was 97.2% to 100.1% and precision 3.4% to 12.7%. The method showed specificity and matrix effect values of < 15%. Minimum absolute recovery percentages (%CV) were 90.5 (5.4), 90.8 (5.0), 95.4 (3.5), and 93.7 (6.9), for LMV, ZDV, LPV, and RTV, respectively. Drug concentrations in patient samples had high inter-individual variability with %CV of 91.98%, 77.54%, 53.80%, and 92.16% for ZDV, LMV, LPV, and RTV, respectively. Two of the 8 patients showed no adherence due to the absence of Protease Inhibitors (PIs) levels in plasma.This technique demonstrated to be effective in therapeutic drug monitoring and is intended to be used in population pharmacokinetics specifically for HIV-positive pregnant women.

Utility of two DNA extraction methods using formalin-fixed paraffin-embedded tissues in identifying congenital cytomegalovirus infection by polymerase chain reaction.

Formalin-fixed paraffin-embedded (FFPE) tissues are a source of biological material for molecular studies; several methods to extract DNA from FFPE tissues have been reported. This process is challenging because of formaldehyde-induced cross-linking between proteins and DNA as well as molecule fragmentation when unbuffered formalin is used for fixation. Here, 2 methods for DNA extraction from FFPE tissues, based on a chelating resin and silica membrane columns, were modified and compared in their capacity to detect human cytomegalovirus (HCMV) in congenital infections. Both methods were tested on 121 samples of brain, lung, spleen, and liver derived from 36 deceased preterm newborns. Twelve patients were selected, and UL55 and UL75 HCMV genes were detected by polymerase chain reaction in 16/36 samples. These 2 methods represent a useful tool for DNA recovery from FFPE tissues and HCMV molecular identification with the advantage of low cost, minimal steps, minimal sample use, being solvent-free, and being easy to implement in the laboratory.

A Proinflammatory Immune Response Might Determine Toxoplasma gondii Vertical Transmission and Severity of Clinical Features in Congenitally Infected Newborns.

Toxoplasma gondii is the etiological agent of toxoplasmosis. Mother-to-child transmission of this parasite can occur during pregnancy. Newborns with congenital toxoplasmosis may develop central nervous system impairment, with severity ranging from subclinical manifestations to death. A proinflammatory/regulated specific immune profile is crucial in the defense against the parasite; nevertheless, its role in the infected pregnant women and the congenitally infected offspring has been poorly explored, and there is still no consensus about its relation to parasite vertical transmission or to severity and dissemination in the congenitally infected newborns. This work aimed to characterize these relations by means of principal component and principal factor analyses. For this purpose, we determined the specific production of the four immunoglobulin G antibody subclasses, cytokines, and lymphocyte proliferation in the T. gondii-infected pregnant women-10 who transmitted the infection to their offspring and seven who did not-as well as in 11 newborns congenitally infected and grouped according to disease severity (five mild and six moderate/severe) and dissemination (four local and seven disseminated). We found that the immune response of nontransmitter women differed from that of the transmitters, the latter having a stronger proinflammatory response, supporting a previous report. We also found that newborns who developed moderate/severe disease presented higher levels of lymphocyte proliferation, particularly of CD8+ and CD19+ cells, a high proportion of tumor necrosis factor α producers, and reduced expression of the immune modulator transforming growth factor ß, as opposed to children who developed mild clinical complications. Our results suggest that a distinctive, not regulated, proinflammatory immune response might favor T. gondii vertical transmission and the development of severe clinical manifestations in congenitally infected newborns.

Medical Outcomes in Women Who Became Pregnant after Vaccination with a Virus-Like Particle Experimental Vaccine against Influenza A (H1N1) 2009 Virus Tested during 2009 Pandemic Outbreak.

The clinical effects and immunological response to the influenza vaccine in women who later become pregnant remain to be thoroughly studied. Here, we report the medical outcomes of 40 women volunteers who became pregnant after vaccination with an experimental virus-like particle (VLP) vaccine against pandemic influenza A(H1N1)2009 (influenza A(H1N1)pdm09) and their infants. When included in the VLP vaccine trial, none of the women were pregnant and were randomly assigned to one of the following groups: (1) placebo, (2) 15 µg dose of VLP vaccine, or (3) 45 µg dose of VLP vaccine. These 40 women reported becoming pregnant during the follow-up phase after receiving the placebo or VLP vaccine. Women were monitored throughout pregnancy and their infants were monitored until one year after birth. Antibody titers against VLP were measured in the mothers and infants at delivery and at six months and one year after birth. The incidence of preeclampsia, fetal death, preterm delivery, and premature rupture of membranes was similar among groups. All vaccinated women and their infants elicited antibody titers (≥1:40). Women vaccinated prior to pregnancy had no adverse events that were different from the nonvaccinated population. Even though this study is limited by the sample size, the results suggest that the anti-influenza A(H1N1)pdm09 VLP experimental vaccine applied before pregnancy is safe for both mothers and their infants.

Maternal Immune Response During Pregnancy and Vertical Transmission in Human Toxoplasmosis.

Toxoplasmosis is a parasitic zoonosis distributed worldwide, caused by the ingestion of contaminated water/food with the parasite Toxoplasma gondii. If a pregnant woman is infected with this parasite, it may be transmitted to the fetus and produce ocular, neurological, or systemic damage with variable severity. The strength and profile of mother's immune response have been suggested as important factors involved in vertical transmission rate and severity of clinical outcome in the congenitally infected fetus. The aim of this work was to evaluate a possible relation between the mother's immune response during pregnancy and congenital transmission to the fetus. We obtained peripheral blood from T. gondii infected pregnant woman and tested it for anti T. gondii (IgG1, IgG2, IgG3, IgG4, and IgA) in serum. Peripheral blood mononuclear cells (PBMCs) were isolated to analyze the in vitro effect of soluble T. gondii antigens on proliferation and production of cytokines. We found that IgG2-4 and IgA antibodies and lymphocytes proliferation, especially CD4+, CD8+, and CD19+ were positive in a higher proportion of cases in transmitter than in non-transmitter women. Furthermore, IgG2-3 and IgA anti-Toxoplasma antibody levels were higher in those mothers who transmitted the infection than in those who did not. Interestingly, a higher proportion of positive cases to IFN-γ and negatives to the immunoregulatory cytokine TGF-ß, were related to T. gondii vertical transmission. Our descriptive results are consistent with the paradoxical previous observations in murine models of congenital toxoplasmosis, which suggest that an increased immune response that protects the mothers from a disseminated or severe disease, and should protect the fetus from infection, is positively related to parasite transmission.

Congenital Zika Syndrome and Extra-Central Nervous System Detection of Zika Virus in a Pre-term Newborn in Mexico.

BACKGROUND: During pregnancy, the Zika virus (ZIKV) replicates in the placenta and central nervous system (CNS) of infected fetuses; nevertheless, the ability of ZIKV to replicate in other fetal tissues has not been extensively characterized. METHODS: We researched whether dissemination of congenitally-acquired ZIKV outside the CNS exists by searching for the accumulation of the viral envelope protein, ZIKV ribonucleic acid (RNA), and infectious viral particles in different organs of a deceased newborn with Congenital Zika Syndrome. A real-time qualitative polymerase chain reaction (qPCR) was used to detect ZIKV RNA in the brain, thymus, lungs, kidneys, adrenal glands, spleen, liver, and small intestine. The same tissues were analyzed by indirect immunofluorescence and immunoperoxidase assays using the monoclonal antibody 4G2 to detect ZIKV envelope antigens. Isolation of infectious ZIKV in a cell culture was carried out using brain and kidney samples. RESULTS: A postmortem, virological analysis of multiple organs, such as the kidneys (epithelial cells in the renal tubules), lungs (bronchial epithelia), thymus (epithelial cells inside the Hassall's corpuscles), and brain (neurons, ependymal cells, and macrophages) revealed the presence of ZIKV RNA and envelope antigens. Other tissues of the deceased newborn tested positive by qPCR for Epstein-Barr virus and human herpesvirus 6, including the brain cortex (Epstein-Barr) and the thymus, kidneys, and adrenal glands (human herpesvirus 6). The kidneys were identified as a significant niche for viral replication, given that infectious particles were successfully isolated from renal tissues. CONCLUSIONS: Our findings demonstrate the ability of congenitally-acquired ZIKV to produce disseminated infections and the viral tropism towards epithelial cells.

Simultaneous quantification of four antiretroviral drugs in breast milk samples from HIV-positive women by an ultra-high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method.

The primary strategy to avoid mother-to-child transmission of human immunodeficiency virus (HIV) through breastfeeding is administration of highly active antiretroviral therapy (HAART) to HIV-positive pregnant women. Because significant changes in the pharmacokinetics of antiretroviral (ARV) drugs occur during pregnancy, quantifying HAART and the viral load in breast milk in this population is essential. Here, we developed an analytical assay for the simultaneous quantification of four ARV drugs in breast milk using ultra-performance liquid chromatography coupled to tandem mass spectrometry. We validated this method following Mexican and international guidelines. ARV drugs. We extracted the ARV drugs from 200 µL samples of breast milk and detected these drugs in a triple quadrupole mass spectrometer with positive electrospray ionization. The validated concentration ranges (ng/mL) for zidovudine, lamivudine, lopinavir, and ritonavir were 12.5-750, 50-2500, 100-5000 and 5 to 250, respectively. Additionally, the absolute recovery percentages (and matrix effects) were 91.4 (8.39), 88.78 (28.75), 91.38 (11.77) and 89.78 (12.37), respectively. We determined that ARV drugs are stable for 24 h at 8°C and 24°C for 15 days at -80°C. This methodology had the capacity for simultaneous detection; separation; and accurate, precise quantification of ARV drugs in human breast milk samples according to Mexican standard laws and United States Food and Drug Administration guidelines.

Characterization of CD127- CD25++ Treg from human colostrum.

PROBLEM: Breastfeeding's influence on the tolerance to environmental antigens is essential for short- and long-term homeostasis for children. Colostrum is rich in leucocytes, but it is unknown whether regulatory T cells (Treg) account for part of this cell population. METHOD OF STUDY: Frequencies of CD127-  CD25++ Treg and levels of immunoregulatory-associated cell markers were determined in colostrum and were compared with autologous blood cells. In addition, we evaluated whether the birth conditions can affect these features. RESULTS: Higher frequencies of CD127 - CD25++ Treg cells expressing Foxp3 and CD45RO were observed in the colostrum. The cells' CD25, CD152, CD279, and TGF-ß expression levels were greater than those in autologous blood cells. In addition, the CD279 and TGF-ß expressions of colostrum CD127-  CD25++ Treg cells were influenced by gestational age and delivery mode. CONCLUSION: The higher proportion of these cells with a function-associated phenotype may reflect certain tolerogenic effects of breastmilk on newborns and infants, contributing to immune system homeostasis.