Differential effects of testosterone on circulating neutrophils, monocytes, and platelets in men: Findings from two trials

Association of testosterone-induced increase in neutrophil and monocyte counts with thromboembolic events: The TRAVERSE trial

BACKGROUND

In epidemiological studies, higher leukocyte and platelet counts are associated with increased risk of cardiovascular events. Effects of testosterone replacement therapy (TRT) on leukocyte subsets and platelets in men with hypogonadism and association of circulating leukocyte subtypes and platelets during TRT with cardiovascular events remain unknown.

METHODS

In the TRAVERSE Trial, 5,204 men, 45-80 years with hypogonadism and preexisting or increased risk of cardiovascular disease (CVD) were randomized to transdermal testosterone or placebo gel daily for up to 5 years. We determined the effect of TRT on neutrophils, monocytes, lymphocytes and platelets and association of changes in leukocyte subtypes and platelets with risk of major adverse cardiovascular (MACE) and venous thromboembolism (VTE) events.

RESULTS

TRT was associated with significantly greater increase in neutrophils and monocytes, and greater decrease in lymphocytes and platelets than placebo. Changes in neutrophil (odds ratio for 1 SD increase in cell count (OR) 1.32 [1.01, 1.73]) and monocyte (OR 1.39 [1.08, 1.79]) counts were associated with increased risk of VTE, accounting for TRT. Neutrophil and monocyte counts at baseline and on-treatment were also associated with increased risk of MACE, adjusting for treatment (baseline: neutrophils OR 1.18 [1.06,1.31], monocytes OR 1.16 [1.05,1.29]; on-treatment neutrophils: OR 1.25 [1.12, 1.40]; monocytes: OR 1.18 [1.06,1.31]).

CONCLUSIONS

TRT increased circulating neutrophils and monocytes and decreased lymphocytes and platelets in men with hypogonadism. Changes in monocyte and neutrophil counts were associated with increased risk of VTE. Neutrophil and monocyte counts should be considered when evaluating VTE risk in hypogonadal men treated with TRT.

CLINICAL TRIAL REGISTRATION

URL:https://clinicaltrials.gov/study/NCT03518034. Unique identifier: NCT03518034. The study was initially registered on March 5, 2018, and the first participant was enrolled on May 23, 2018.

Testosterone exacerbates neutrophilia and cardiac injury in myocardial infarction via actions in bone marrow

Men develop larger infarct sizes than women after a myocardial infarction (MI), but the mechanism underlying this sex difference is unknown. Here, we demonstrated that blood neutrophil counts post-MI were higher in male than female mice. Castration-induced testosterone deficiency reduced blood neutrophil counts to the level in females and increased survival post-MI. These effects were mimicked by Osterix-directed ablation of the androgen receptor in bone marrow (BM). Mechanistically, androgens downregulated the leukocyte retention factor CXCL12 in BM stromal cells. Post-hoc analysis of clinical trial data showed that neutrophilia was greater in men than women after reperfusion of first-time ST-elevation MI, and tocilizumab, an interleukin-6 receptor inhibitor, reduced blood neutrophil counts and infarct size to a greater extent in men than women. Our work reveals a previously unknown mechanism connecting testosterone with neutrophilia and MI injury via BM and identifies the importance of considering sex when developing anti-inflammatory strategies to treat MI.

A researcher's guide to studying sex differences in immune aging

Sex differences in immune system aging significantly impact disease susceptibility and vaccine responses among older adults, but with notable disparities between men and women. This area has gained importance because vaccines can exhibit differential efficacy by sex in aging populations, underscoring the need for sex-specific strategies. As the global population ages, understanding these sex-based immune differences is crucial for developing targeted interventions for age-related diseases. Addressing these disparities requires robust preclinical models that mimic human immune aging to uncover mechanisms and inform personalized approaches. In this review we assess the translational potential of preclinical mouse models in studying sex differences in immune aging, and emphasize the urgency of sex-specific interventions to improve health outcomes in older adults.

Neutrophil-to-lymphocyte ratio and its correlation with tuberculosis infection: a cross-sectional survey based on the NHANES database

Background

Tuberculosis infection (TBI) is a major challenge to global public health. Early detection and treatment of TBI are crucial in preventing tuberculosis (TB). Although inflammation is closely linked to the pathogenesis of TBI, the neutrophil-to-lymphocyte ratio (NLR), as a new inflammatory marker, has been less studied with TBI risk. This study was based on the National Health and Nutrition Examination Survey (NHANES) database. We utilized a cross-sectional research method to explore the association between NLR and the risk of adult TBI, aiming to fill the blank in the studying relationship between NLR and TBI risk. Our findings may contribute to providing new biomarkers for the diagnosis and treatment of TBI.

Methods

In this cross-sectional research, data from the NHANES database for the periods 1999-2000 and 2011-2012 were pooled for the study, with TBI as the dependent variable and NLR as the independent variable. A total of 2,433 participants were enrolled, including 391 TBI patients and 2,042 non-TBI patients. The inclusion criteria included information from complete blood testing and TBI status assessment. We evaluated demographic characteristics and clinical factors such as body mass index (BMI), smoking, drinking, NLR, and TBI risk. We employed weighted logistic regression to set up a relationship model between NLR and TBI and dissected the association between them through stratified analysis and subgroup analysis with confounding factors adjusted. We also utilized restricted cubic spline (RCS) and Kaplan-Meier (K-M) survival curves to investigate the nonlinear relationship between NLR and TBI, as well as their relationship with survival rates.

Results

A total of 2,433 samples were included in this project, with 391 TBI patients and 2,042 non-TBI patients. In the multivariable weighted logistic regression model, an obvious negative association was observed between NLR and TBI risk [odds ratio (OR) <1, P<0.05], and it was substantially influenced by diabetes (P for interaction =0.049). The negative association between NLR and TBI risk was particularly remarkable (P<0.05) in male and hypertensive patients. The RCS curve indicated a potential linear relationship between NLR and TBI risk (P-non-linear =0.9561), with NLR >1.899, OR <1, being a protective factor. The K-M survival curve revealed an obvious linkage between high NLR (>2.328) and increased death risk in TBI patients.

Conclusions

NLR is remarkably negatively linked with TBI risk. Patients with excessively high NLR have worse outcomes.

Exploring the role of sex hormones and gender diversity in multiple sclerosis

Sex and sex hormones are thought to influence multiple sclerosis (MS) through effects on inflammation, myelination and neurodegeneration, and exogenous hormones have been explored for their therapeutic potential. However, our understanding of how sex hormones influence MS disease processes and outcomes remains incomplete. Furthermore, our current knowledge is derived primarily from studies that focus exclusively on cisgender populations with exclusion of gender-diverse people. Gender-affirming hormone therapy comprising exogenous sex hormones or sex hormone blocking agents are commonly used by transgender and gender-diverse individuals, and it could influence MS risk and outcomes at various stages of disease. A better understanding of the impact and potential therapeutic effects of both endogenous and exogenous sex hormones in MS is needed to improve care and outcomes for cisgender individuals and, moreover, for gender-diverse populations wherein an evidence base does not exist. In this Perspective, we discuss the effects of endogenous and exogenous sex hormones in MS, including their potential therapeutic benefits, and examine both established sex-based dimorphisms and the potential for gender-diverse dimorphisms. We advocate for future research that includes gender-diverse people to enhance our knowledge of the interplay of sex and sex hormones in MS, leading to the development of more effective and inclusive treatment strategies and improvement of care for all individuals with MS.

Independent effects of testosterone, estradiol, and sex chromosomes on gene expression in immune cells of trans- and cisgender individuals

The origins of sex differences in human disease are elusive, in part because of difficulties in separating the effects of sex hormones and sex chromosomes. To separate these variables, we examined gene expression in four groups of trans- or cisgender individuals: XX individuals treated with exogenous testosterone (n=21), XY treated with exogenous estradiol (n=13), untreated XX (n=20), and untreated XY (n=15). We performed single-cell RNA-sequencing of 358,426 peripheral blood mononuclear cells. Across the autosomes, 8 genes responded with a significant change in expression to testosterone, 34 to estradiol, and 32 to sex chromosome complement with no overlap between the groups. No sex-chromosomal genes responded significantly to testosterone or estradiol, but X-linked genes responded to sex chromosome complement in a remarkably stable manner across cell types. Through leveraging a four-state study design, we successfully separated the independent actions of testosterone, estradiol, and sex chromosome complement on genome-wide gene expression in humans.

Sex-Specific Associations between Thyroid Status, Inflammation and Hemostasis Biomarkers in Patients with Subacute Thyroiditis

Background: Subacute thyroiditis (SAT) is characterized by profound inflammation and fluctuations in thyroid hormones which may affect the hemostasis balance. This study investigates sex-specific associations between thyroid status, inflammation and hemostasis biomarkers in SAT. Methods: We included 52 patients (40 women and 12 men) treated with non-steroidal anti-inflammatory drugs (NSAID) or methylprednisolone (MPS). Free thyroxine (fT4), thyroid stimulating hormone, C-reactive protein, complete blood count and routine hemostasis parameters were assessed. Results: Both men and women were in hyperthyroid state and had comparable levels of inflammatory biomarkers. A shortened activated partial thromboplastin time (aPTT) was observed in 16.7% of the men and 10% of the women (p = 0.562), and a shortened prothrombin time (PT) was observed in 33% of the men and 12.5% of the women (p = 0.094). In men, aPTT positively correlated with fT4 (r = 0.627; p < 0.05), while PT positively correlated with leukocyte-based inflammatory indices in women (p < 0.05). NSAID-treated patients had lower aPTTs and platelet counts than those treated with MPS (p < 0.05). Principal component analysis extracted "proinflammatory", "prothrombotic" and "antithrombotic" factors, but the "proinflammatory" factor was the independent predictor of elevated fT4 in women (OR = 2.705; p = 0.036). Conclusions: Our data demonstrated sex-specific associations of thyroid status and inflammatory biomarkers with hemostasis parameters in SAT. Routine hemostasis screening tests may help in monitoring the changes in the hemostasis system over the course of SAT.

Implications for neutrophils in cardiac arrhythmias

Cardiac arrhythmias commonly occur as a result of aberrant electrical impulse formation or conduction in the myocardium. Frequently discussed triggers include underlying heart diseases such as myocardial ischemia, electrolyte imbalances, or genetic anomalies of ion channels involved in the tightly regulated cardiac action potential. Recently, the role of innate immune cells in the onset of arrhythmic events has been highlighted in numerous studies, correlating leukocyte expansion in the myocardium to increased arrhythmic burden. Here, we aim to call attention to the role of neutrophils in the pathogenesis of cardiac arrhythmias and their expansion during myocardial ischemia and infectious disease manifestation. In addition, we will elucidate molecular mechanisms associated with neutrophil activation and discuss their involvement as direct mediators of arrhythmogenicity.

Androgen exposure impairs neutrophil maturation and function within the infected kidney

Urinary tract infections (UTIs) in men are uncommon yet carry an increased risk for severe pyelonephritis and other complications. In models of Escherichia coli UTI, C3H/HeN mice develop high-titer pyelonephritis (most with renal abscesses) in a testosterone-dependent manner, but the mechanisms underlying this phenotype are unknown. Here, using female mouse models, we show that androgen exposure impairs neutrophil maturation in the upper and lower urinary tract, compounded by a reduction of neutrophil function within the infected kidney, enabling persistent high-titer infection and promoting abscess formation. Following intravesical inoculation with uropathogenic E. coli (UPEC), kidneys of androgen-exposed C3H mice showed delayed local pro-inflammatory cytokine responses while robustly recruiting neutrophils. These were enriched for an end-organ-specific population of aged but immature neutrophils (CD49d+, CD101-). Compared to their mature counterparts, these aged immature kidney neutrophils exhibited reduced function in vitro, including impaired degranulation and diminished phagocytic activity, while splenic, bone marrow, and bladder neutrophils did not display these alterations. Furthermore, aged immature neutrophils manifested little phagocytic activity within intratubular UPEC communities in vivo. Experiments with B6 conditional androgen receptor (AR)-deficient mice indicated rescue of the maturation defect when AR was deleted in myeloid cells. We conclude that the recognized enhancement of UTI severity by androgens is attributable, at least in part, to local impairment of neutrophil maturation in the urinary tract (largely via cell-intrinsic AR signaling) and a kidney-specific reduction in neutrophil antimicrobial capacity.IMPORTANCEAlthough urinary tract infections (UTIs) predominantly occur in women, male UTIs carry an increased risk of morbidity and mortality. Pyelonephritis in androgen-exposed mice features robust neutrophil recruitment and abscess formation, while bacterial load remains consistently high. Here, we demonstrate that during UTI, neutrophils infiltrating the urinary tract of androgen-exposed mice exhibit reduced maturation, and those that have infiltrated the kidney have reduced phagocytic and degranulation functions, limiting their ability to effectively control infection. This work helps to elucidate mechanisms by which androgens enhance UTI susceptibility and severity, illuminating why male patients may be predisposed to severe outcomes of pyelonephritis.

Testosterone affects type I/type II interferon response of neutrophils during hepatic amebiasis

Differences in immune response between men and women may influence the outcome of infectious diseases. Intestinal infection with Entamoeba histolytica leads to hepatic amebiasis, which is more common in males. Previously, we reported that innate immune cells contribute to liver damage in males in the murine model for hepatic amebiasis. Here, we focused on the influences of sex and androgens on neutrophils in particular. Infection associated with neutrophil accumulation in the liver was higher in male than in female mice and further increased after testosterone treatment in both sexes. Compared with female neutrophils, male neutrophils exhibit a more immature and less activated status, as evidenced by a lower proinflammatory N1-like phenotype and deconvolution, decreased gene expression of type I and type II interferon stimulated genes (ISGs) as well as downregulation of signaling pathways related to neutrophil activation. Neutrophils from females showed higher protein expression of the type I ISG viperin/RSAD2 during infection, which decreased by testosterone substitution. Moreover, ex vivo stimulation of human neutrophils revealed lower production of RSAD2 in neutrophils from men compared with women. These findings indicate that sex-specific effects on neutrophil physiology associated with maturation and type I IFN responsiveness might be important in the outcome of hepatic amebiasis.

Interleukin-10-producing monocytes contribute to sex differences in pain resolution in mice and humans

Pain is closely associated with the immune system, which exhibits sexual dimorphism. For these reasons, neuro-immune interactions are suggested to drive sex differences in pain pathophysiology. However, our understanding of peripheral neuro-immune interactions on sex differences in pain resolution remains limited. Here, we have shown, in both a mouse model of inflammatory pain and in humans following traumatic pain, that males had higher levels of interleukin (IL)-10 than females, which were correlated with faster pain resolution. Following injury, we identified monocytes (CD11b+ Ly6C+ Ly6G-F4/80 mid ) as the primary source of IL-10, with IL-10-producing monocytes being more abundant in males than females. In a mouse model, neutralizing IL-10 signaling through antibodies, genetically ablating IL-10R1 in sensory neurons, or depleting monocytes with clodronate all impaired the resolution of pain hypersensitivity in both sexes. Furthermore, manipulating androgen levels in mice reversed the sexual dimorphism of pain resolution and the levels of IL-10-producing monocytes. These results highlight a novel role for androgen-driven peripheral IL-10-producing monocytes in the sexual dimorphism of pain resolution. These findings add to the growing concept that immune cells play a critical role in resolving pain and preventing the transition into chronic pain.

Graphical abstract

Associations Between Leisure-Time Physical Activity Level and Peripheral Immune Cell Populations in the US General Population, Analysis of the National Health and Nutrition Examination Survey Data, 1999-2018

BACKGROUND

Chronic levels of inflammation are associated with higher risk of many chronic diseases. Physical activity (PA) lowers the risk of cancer, cardiovascular disease (CVD), diabetes and others. One mechanism for PA-induced protection may be through the immune system. We investigated the association between leisure-time PA and peripheral immune cell populations in a large nationally representative sample of the US general population.

METHODS

A total of 17,093 participants [mean (SE) age of 41.6 (0.3) years] of the National Health and Nutrition Examination Survey 1999-2018 were included. Self-reported leisure-time PA was converted to metabolic equivalent of task hours per week (MET-hrs/wk). White blood cell (WBC) count, WBC ratios, and platelet count were derived. Multivariable linear regression analyses were used to estimate associations between leisure-time PA level and peripheral immune cell populations. Multivariable logistic regression analyses were used to estimate associations between leisure-time PA and metrics of WBC count and neutrophil-to-lymphocyte ratio (NLR) which may predict mortality.

RESULTS

A higher leisure-time PA level was associated with a lower WBC count (> 14.0 vs. < 1.2 MET-hrs/wk adjusted mean (95% confidence interval [CI]): 7.12 (6.86, 7.38) vs. 7.38 (7.12, 7.64) 1000 cells/μL, Ptrend < 0.001) and a lower NLR (> 14.0 vs. < 1.2 MET-hrs/wk adjusted mean (95% CI) 2.04 (1.90, 2.18) vs. 2.13 (1.99, 2.28), Ptrend = 0.007). Leisure-time PA level was not associated with lymphocyte-to-monocyte ratio (LMR; Ptrend = 0.25) or platelet-to-lymphocyte ratio (PLR; Ptrend = 0.69). Compared to the lowest leisure-time PA level (< 1.2 MET-hrs/wk), the highest leisure-time PA level (≥ 14.0 MET-hrs/wk) was associated with a lower probability of a high WBC count (> 8.1 × 109 cells/L; odds ratio [OR] = 0.76, 95% CI = 0.66-0.88) and high NLR (> 2.68; OR = 0.84, 95% CI = 0.72-0.99), which may predict CVD and all-cause mortality. The highest leisure-time PA level also linked to a lower probability of a high WBC count (≥ 8.3 × 109 cells/L; OR = 0.76, 95% CI = 0.66-0.88), which may predict cancer mortality.

CONCLUSIONS

We observed an inverse association between leisure-time PA level, WBC count, and NLR, particularly for neutrophil levels. These results suggest that participants at higher levels of leisure-time PA may have lower levels of inflammation, which may be important for future chronic disease outcomes.

Influence of androgens on the innate immune system

BACKGROUND

Sexual dimorphism is observed in the occurrence, course, and severity of human disease. The difference in immune response between males and females can in part be attributed to sexual genotype. However, immunological differences can also be explained by endocrine-immune interactions. Specifically, androgens possess the ability of directly modulating the development and function of immune cells. Although androgens generally contribute to immunosuppressive effects, this is not necessarily always the case.

AIM

The aim of the review is to uncover the role of androgens in shaping the innate immune response.

MATERIAL & METHODS

Authors included papers in this review which discussed the impact of androgens on specific innate immune cells.

RESULTS

Androgens modulate the innate immune response through various mechanisms. However, there is conflicting evidence in the literature regarding the interplay betwen androgens and the innate immune system.

DISCUSSION

Conflicting evidence presented in this review could in part be explained by the limitations present in interpreting results.

CONCLUSION

This review is of great importance for our understanding of occurence and mechanism of human inflammatory disease.

Gender-Specific Impact of Sex Hormones on the Immune System

Sex hormones are key determinants of gender-related differences and regulate growth and development during puberty. They also exert a broad range modulation of immune cell functions, and a dichotomy exists in the immune response between the sexes. Both clinical and animal models have demonstrated that androgens, estrogens, and progestogens mediate many of the gender-specific differences in immune responses, from the susceptibility to infectious diseases to the prevalence of autoimmune disorders. Androgens and progestogens mainly promote immunosuppressive or immunomodulatory effects, whereas estrogens enhance humoral immunity both in men and in women. This study summarizes the available evidence regarding the physiological effects of sex hormones on human immune cell function and the underlying biological mechanisms, focusing on gender differences triggered by different amounts of androgens between males and females.

The Similarities and Differences between the Effects of Testosterone and DHEA on the Innate and Adaptive Immune Response

Androgens are steroids that modulate various processes in the body, ranging from reproduction, metabolism, and even immune response. The main androgens are testosterone, dihydrotestosterone (DHT) and dehydroepiandrosterone (DHEA). These steroids modulate the development and function of immune response cells. Androgens are generally attributed to immunosuppressive effects; however, this is not always the case. Variations in the concentrations of these hormones induce differences in the innate, humoral, and cell-mediated immune response, which is concentration dependent. The androgens at the highest concentration in the organism that bind to the androgen receptor (AR) are DHEA and testosterone. Therefore, in this work, we review the effects of DHEA and testosterone on the immune response. The main findings of this review are that DHEA and testosterone induce similar but also opposite effects on the immune response. Both steroids promote the activation of regulatory T cells, which suppresses the Th17-type response. However, while testosterone suppresses the inflammatory response, DHEA promotes it, and this modulation is important for understanding the involvement of androgens in infectious (bacterial, viral and parasitic) and autoimmune diseases, as well as in the sexual dimorphism that occurs in these diseases.

Haematological actions of androgens

In this review, we discuss the effects on androgens on the haemopoietic system, focussing largely on the effects of testosterone on erythropoiesis. Stimulation of erythropoiesis is one of the most consistent effects of testosterone treatment observed in clinical trials. In men with anaemia this effect can be beneficial. Conversely, erythrocytosis is one of the most common adverse effects of testosterone treatment with a relative risk of 8.14 (95% CI: 1.87-35.40) estimated by a recent meta-analysis of randomised placebo controlled clinical trials. A reduction in haemoglobin is commonly seen in men receiving androgen deprivation therapy for prostate cancer, and in transwomen receiving gender affirming therapy to reduce serum testosterone. While mechanisms by which androgens regulate erythropoiesis are not fully understood, it is likely that effects on erythropoietic progenitor cells and erythropoietin are involved, with secondary effects on iron metabolism. In contrast, whether androgens exert clinically relevant effects on white blood cells and on platelets requires further study.

Sex Steroids Effects on Asthma: A Network Perspective of Immune and Airway Cells

A multitude of evidence has suggested the differential incidence, prevalence and severity of asthma between males and females. A compilation of recent literature recognized sex differences as a significant non-modifiable risk factor in asthma pathogenesis. Understanding the cellular and mechanistic basis of sex differences remains complex and the pivotal point of this ever elusive quest, which remains to be clarified in the current scenario. Sex steroids are an integral part of human development and evolution while also playing a critical role in the conditioning of the immune system and thereby influencing the function of peripheral organs. Classical perspectives suggest a pre-defined effect of sex steroids, generalizing estrogens popularly under the “estrogen paradox” due to conflicting reports associating estrogen with a pro- and anti-inflammatory role. On the other hand, androgens are classified as “anti-inflammatory,” serving a protective role in mitigating inflammation. Although considered mainstream and simplistic, this observation remains valid for numerous reasons, as elaborated in the current review. Women appear immune-favored with stronger and more responsive immune elements than men. However, the remarkable female predominance of diverse autoimmune and allergic diseases contradicts this observation suggesting that hormonal differences between the sexes might modulate the normal and dysfunctional regulation of the immune system. This review illustrates the potential relationship between key elements of the immune cell system and their interplay with sex steroids, relevant to structural cells in the pathophysiology of asthma and many other lung diseases. Here, we discuss established and emerging paradigms in the clarification of observed sex differences in asthma in the context of the immune system, which will deepen our understanding of asthma etiopathology.

Gender-Diverse Inclusion in Immunological Research: Benefits to Science and Health

The differences between male and female immune systems are an under-researched field, ripe for discovery. This is evidenced by the stark sex biases seen in autoimmunity and infectious disease. Both the sex hormones (oestrogen and testosterone), as well as the sex chromosomes have been demonstrated to impact immune responses, in multiple ways. Historical shortcomings in reporting basic and clinical scientific findings in a sex-disaggregated manner have led not only to limited discovery of disease aetiology, but to potential inaccuracies in the estimation of the effects of diseases or interventions on females and gender-diverse groups. Here we propose not only that research subjects should include both cis-gender men and cis-gender women, but also transgender and gender-diverse people alongside them. The known interaction between the hormonal milieu and the sex chromosomes is inseparable in cis-gender human research, without the confounders of puberty and age. By inclusion of those pursuing hormonal affirmation of their gender identity- the individual and interactive investigation of hormones and chromosomes is permitted. Not only does this allow for a fine-tuned dissection of these individual effects, but it allows for discovery that is both pertinent and relevant to a far wider portion of the population. There is an unmet need for detailed treatment follow-up of the transgender community- little is known of the potential benefits and risks of hormonal supplementation on the immune system, nor indeed on many other health and disease outcomes. Our research team has pioneered the inclusion of gender-diverse persons in our basic research in adolescent autoimmune rheumatic diseases. We review here the many avenues that remain unexplored, and suggest ways in which other groups and teams can broaden their horizons and invest in a future for medicine that is both fruitful and inclusive.

Sex Differences in Differentiated Thyroid Cancer

Background: Sex dimorphism strongly impacts tumor biology, with most cancers having a male predominance. Uniquely, thyroid cancer (TC) is the only nonreproductive cancer with striking female predominance with three- to four-fold higher incidence among females, although males generally have more aggressive disease. The molecular basis for this observation is not known, and current approaches in treatment and surveillance are not sex specific. Summary: Although TC has overall good prognosis, 6-20% of patients develop regional or distant metastasis, one third of whom are not responsive to conventional treatment approaches and suffer a 10-year survival rate of only 10%. More efficacious treatment strategies are needed for these aggressive TCs, as tyrosine kinase inhibitors and immunotherapy have major toxicities without demonstrable overall survival benefit. Emerging evidence indicates a role of sex hormones, genetics, and the immune system in modulation of both risk for TC and its progression in a sex-specific manner. Conclusion: Greater understanding of the molecular mechanisms underlying sex differences in TC pathogenesis could provide insights into the development of sex-specific, targeted, and effective strategies for prevention, diagnosis, and management. This review summarizes emerging evidence for the importance of sex in the pathogenesis, progression, and response to treatment in differentiated TC with emphasis on the role of sex hormones, genetics, and the immune system.

Exploring pleiotropic effects of lipid modifiers on coagulation and hemostasis with genetics

BACKGROUND

Statins have long been suspected to have pleiotropic effects via thrombotic factors. Randomized controlled trials are too limited to be definitive. We examined the associations of genetically mimicking effects of statins, PCSK9 inhibitors and alternative lipid targets (in genes LDLR, APOC3, and LPL) on key indicators of coagulation system function, i.e., prothrombin time (PT) and activated partial thromboplastin time (aPTT).

METHODS

We assessed the effect of established genetic mimics of effects of lipid modifiers and alternative lipid treatment targets on PT (n=58,110) and aPTT (n=37,767), all transformed to z-scores, using Mendelian randomization taking advantage of Biobank Japan. Ischemic heart disease (IHD) was a control outcome.

RESULTS

Genetically mimicked effects of statins increased PT by 0.31 standard deviation (SD) per SD increase in LDL (95% confidence interval (CI) 0.10 to 0.51) based on rs12916 but did not affect aPTT. Genetically mimicking effects of targeting LDLR increased PT based on rs688 (0.33 SD per SD increase in TG, 95% CI 0.03 to 0.63) but did not affect aPTT. Genetically mimicking effects of PCSK9 inhibitors or targeting APOC3, or LPL had no effect on PT or aPTT. Genetically mimicking effects of statins, PCSK9 inhibitors and alternative lipid targets reduced risk of IHD in Biobank Japan.

CONCLUSION

Statins, and possibly targeting LDLR, may also act via a coagulation cascade factor, likely specific to the extrinsic or common pathway. Further elucidation of the mechanistic pathway may facilitate development of new interventions and inform use of statins particularly in relation to use of other anticoagulants.

Interindividual Biological Variability of Reticulocytes and Their Maturation Fractions in the Pediatric Population

OBJECTIVES

Because published data about the variability of reticulocyte counts in children are scarce, the interindividual biological variability of the automated reticulocyte count and its maturation fractions according to age and sex were analyzed.

METHODS

A retrospective, observational, analytical study was designed to establish and compare normal values of the automated reticulocyte count and its maturation fractions in different age and sex groups. The sample was drawn from results of CBC counts performed in children aged between 2 months and 18 years using an indirect sampling methodology.

RESULTS

A total of 9,362 CBC counts were analyzed. Automated reticulocyte count decreased between 2 months and 3 years of age and slowly increased thereafter, showing higher values in girls up to the age of 9 years, and equalized by sex thereafter. Immature reticulocyte fraction increased until 7 months of age; decreased progressively until 4 years of age; and then showed a discreet but constant rise, with significantly higher values in boys older than 1 year. The low-fluorescence fraction was relatively steady, with significantly higher values in girls aged 8 months and older.

CONCLUSIONS

The automated reticulocyte count and its maturation fractions show significant variations related to age and sex in pediatric patients.

The relationship between 2D:4D ratio and postpartum adult female variables in a Ghanaian population

OBJECTIVES

Postpartum hematological and anthropometric assessment is a requirement for optimal maternal and child health. The study aimed to determine the relationship between the 2D:4D ratio and postpartum hematological and anthropometric variables in adult females.

METHODS

The study was cross-sectional from December 2020 to April 2021 involving 272 postpartum adult females, aged between 18 and 36 years. The right (2D:4DR) and the left (2D:4DL) digit ratios were measured using computer-assisted analysis. Fasting venous samples were collected at a median (interquartile range) of 111 (44-210) days postpartum and analyzed for total testosterone (TT), estradiol, sex hormone-binding globulin, and complete blood count.

RESULTS

The mean ± standard deviation 2D:4DR and 2D:4DL were 0.94 ± 0.04 and 0.93 ± 0.04, respectively. As expected, the TT (r = -0.198, p = .015) and the free androgen index (FAI: r = -0.186, p = .019) were inversely correlated with the 2D:4DL while free testosterone (FT%: r = -0.157, p = .038) was inversely correlated with the 2D:4DR. The absolute basophile count (BASO: r = -0.124, p = .040) and the Platelet-lymphocyte ratio (PLR: r = -0.153, p = .016) were inversely correlated with the 2D:4DL and the 2D:4DR respectively. In addition, the mean cell volume was inversely correlated with the 2D:4DR (r = -0.139, p = .024) and the 2D:4DL (r = -0.122, p = .045). Moreover, the 2D:4DR was inversely correlated with height (r = -0.164, p = .007). Unexpectedly, the red blood cell count (RBC: r = 0.138, p = .025) was positively correlated with the 2D:4DR.

CONCLUSION

There are significant relationships between the 2D:4D ratio and postpartum female variables. These findings are useful preliminary reference data for postpartum research and subsequent 2D:4D ratio studies.