Immune system adaptation during gender-affirming testosterone treatment

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.

Systems-level immunomonitoring in children with solid tumors to enable precision medicine

Cancer is the leading cause of death from disease in children. Survival depends not only on surgery, cytostatic drugs, and radiation but also on systemic immune responses. Factors influencing these immune responses in children of different ages and tumor types are unknown. Novel immunotherapies can enhance anti-tumor immune responses, but few children have benefited, and markers of effective responses are lacking. Here, we present a systems-level analysis of immune responses in 191 children within a population-based cohort with diverse tumors and reveal that age and tumor type shape immune responses differently. Systemic inflammation and cytotoxic T cell responses correlate with tumor mutation rates and immune cell infiltration. Clonally expanded T cell responses are rarely detected in blood or tumors at diagnosis but are sometimes elicited during treatment. Expanded T cells are similarly regulated in children and adults with more immunogenic cancers. This research aims to facilitate the development of precision immunotherapies for children with cancer.

Immune dynamics throughout life in relation to sex hormones and perspectives gained from gender-affirming hormone therapy

Biological sex is closely associated with the properties and extent of the immune response, with males and females showing different susceptibilities to diseases and variations in immunity. Androgens, predominantly in males, generally suppress immune responses, while estrogens, more abundant in females, tend to enhance immunity. It is also established that sex hormones at least partially explain sex biases in different diseases, particularly autoimmune diseases in females. These differences are influenced by hormonal, genetic, and environmental factors, and vary throughout life stages. The advent of gender-affirming hormone therapy offers a novel opportunity to study the immunological effects of sex hormones. Despite the limited studies on this topic, available research has revealed that testosterone therapy in transgender men may suppress certain immune functions, such as type I interferon responses, while increasing inflammation markers like TNF-α. Transgender women on estrogen therapy also experience alterations in coagulation-related and inflammatory characteristics. Furthermore, other possible alterations in immune regulation can be inferred from the assessment of inflammatory and autoimmune markers in transgender individuals receiving hormone therapy. Understanding the complex interactions between sex hormones and the immune system, particularly through the unique perspective offered by gender-affirming hormone therapies, may facilitate the development of targeted therapies for infections and autoimmune diseases while also improving healthcare outcomes for transgender individuals. Here we review immune dynamics throughout life in both sexes and provide a summary of novel findings drawn from studies exploring gender-affirming hormone therapy.

Prevalence and risk factors for long COVID in China: A systematic review and meta-analysis of observational studies

BACKGROUND

With the outbreak of COVID-19 in China, a large number of COVID-19 patients are at risk of long COVID after recovery. The purpose of our research is to systematically review the existing clinical studies to understand the current prevalence and related risk factors of long COVID in COVID-19 patients in China.

METHODS

The protocol of this systematic review was registered on PROSPERO (CRD42024519375). We searched six electronic databases from 1st January 2020-1st March 2024. Literature screening, data extraction, and risk bias assessment were independently carried out by two reviewers. Quality of the included studies was evaluated by AHRQ and NOS. The meta-analysis was performed by R software 4.2.3 to derive the prevalence of long COVID and risk factors.

RESULTS

Overall, 50 studies with 65880 participants were included. The results showed that the prevalence of long COVID (with at least one symptom) among the COVID-19 patients was approximately 50 % (95 %Confidence Interval (CI) 42-58 %) in China. Although we conducted meta-regression and subgroup analysis, the heterogeneity of the study was high. But the Omicron BA.2 variant had a statistically significant effect on the prevalence of long COVID (P = 0.0004). The three most common symptoms of long COVID were fatigue (0.33, 95 %CI 0.28-0.39), cognitive decline (0.30, 95 %CI 0.14-0.46) and shortness of breath (0.29, 95 %CI 0.15-0.43). Patients with severe acute phase of COVID-19 (Odds Ratio (OR) 1.57, 95 % CI 1.39-1.77), combined 2 comorbidities (OR 1.80, 95 % CI 1.40-2.32), combined 3 comorbidities (OR 2.13, 95 % CI 1.64-2.77), advanced age (OR 1.02, 95 % CI 1.01-1.04), female (OR 1.58, 95 % CI 1.44-1.73) were the risk factors for long COVID prevalence.

CONCLUSION

Current systematic review found that nearly half of COVID-19 patients may suffering from long COVID in China. Establishing a long COVID recovery-support platform and regular follow-up would help to long-term monitor and manage the patients, especially those high-risk population.

Sex-specific cut-off for dilute Russell's viper venom time lupus anticoagulant test may be of value

Background

Current guidelines recommend application of the 99th percentile to determine the cut-off value on at least 120 healthy donors regardless of sex for lupus anticoagulant (LA) ratio of each step. However, a statistically significant difference between the sexes has been found for LA ratio recently.

Objectives

To clarify whether this sex difference in dilute Russell's viper venom time (DRVVT) exists in various detection systems and the necessity of setting sex-specific cut-off values.

Methods

Blood samples from healthy donors were detected on 3 DRVVT detection systems, and the sex-specific cut-offs of DRVVT test were obtained based on the 99th or 97.5th centile of screen, confirm, and normalized ratios (NRs) grouped by sex in each system. One thousand one hundred twenty one female patients with suspected antiphospholipid syndrome (APS) were retrospectively investigated, the APS-associated clinical and laboratory characteristics of female patients stratified by different cut-offs of DRVVT ratio were compared.

Results

The DRVVT NRs of females were significantly lower than those of males on each system. The female patients with DRVVT NR between female-specific and regardless of sex cut-offs had higher positive rates of silica clotting time test and LA retest results after 12 weeks than those with DRVVT NRs lower than female-specific cut-off, there were also more patients who met the APS clinical criteria.

Conclusion

The sex difference of the cut-off value for DRVVT LA test is confirmed on multiple systems, the female-specific cut-off is lower than regardless of sex cut-off and may lead to more female patients being considered as high-risk population for APS.

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.

Sex hormone imbalance and rheumatoid arthritis in American men: a cross-sectional analysis from NHANES 2011-2016

Background

Emerging evidence suggests that sex hormones, particularly testosterone and sex hormone-binding globulin (SHBG), play a critical role in the pathophysiology of Rheumatoid arthritis (RA). However, the precise relationship between these hormonal factors and RA risk in men remains underexplored.

Methods

We conducted a cross-sectional analysis using data from the National Health and Nutrition Examination Survey (NHANES) 2011-2016. A total of 3,110 male participants were included after excluding those with missing data on testosterone, SHBG, RA, or key covariates. Serum testosterone and SHBG levels were measured, and RA status was determined based on self-reported physician diagnosis. Multivariate logistic regression models were used to assess the association between testosterone, SHBG, and RA. Restricted cubic spline (RCS) regression was applied to explore nonlinear relationships. Subgroup and interaction analyses were performed to assess effect modifications by age, race/ethnicity, body mass index (BMI), hypertension, and poverty-income ratio (PIR).

Results

Of the 3,110 men analyzed, 191 were diagnosed with RA. Low testosterone levels (<300 ng/dL) were significantly associated with increased RA risk (OR = 2.30, 95% CI: 1.65-3.21, p < 0.001), and elevated SHBG levels (>57 nmol/L) were also associated with a higher risk of RA (OR = 1.65, 95% CI: 1.14-2.39, p = 0.008). RCS analysis indicated a nonlinear relationship between testosterone, SHBG, and RA risk, with sharp increases in RA risk at the lower ends of testosterone and SHBG levels. Interaction analyses revealed that age, race/ethnicity, hypertension, and PIR significantly modified the relationship between these hormonal factors and RA, while BMI did not exhibit any significant interaction.

Conclusion

This study provides evidence that low testosterone and high SHBG levels are associated with an increased risk of RA in men. These associations are nonlinear and modified by factors such as age, race/ethnicity, hypertension, and PIR. Our findings highlight the importance of considering hormonal status in RA risk assessment and suggest potential avenues for targeted therapeutic strategies aimed at hormonal regulation.

Long COVID-19 outcomes of patients with pre-existing dementia

BACKGROUND

Although COVID-19 has been linked to worse acute outcomes in patients with some neurodegenerative disorders, its long-term impact on dementia remains unclear.

OBJECTIVE

To investigate the outcomes of COVID-19 survivors with dementia.

METHODS

This retrospective study evaluated 9806 patients with dementia in the Montefiore Health System (January 2016 to July 2023). Comparisons were made between dementia patients with and without a positive SARS-CoV-2 polymerase-chain-reaction test who had a follow-up at least two weeks post-infection. Outcomes included all-cause mortality, major adverse cardiovascular events (MACE), new-onset dysphagia, dyspnea, fatigue, new-onset sleep disturbances, altered mental status, first-time fall, headache, new-onset depression, and new-onset anxiety. Adjusted hazard ratios (aHR) were computed adjusting for age, sex, race, ethnicity, and pre-existing comorbidities.

RESULTS

Dementia patients with COVID-19 were younger, more likely to be male, and had a higher prevalence of major pre-existing comorbidities compared to those without COVID-19. Patients who survived acute COVID-19 were more likely to die than non-COVID controls after adjusting for covariates (aHR = 1.65 [1.43, 1.91]). COVID-19 was significantly associated with higher risk of MACE (aHR = 1.58 [1.41, 1.78]), new-onset dysphagia (aHR = 1.64 [1.42, 1.91]), dyspnea (aHR = 1.27 [1.12, 1.44]), fatigue (aHR = 1.42 [1.22, 1.65]), new-onset sleep disturbances (aHR = 1.36 [1.15, 1.60]), altered mental status (aHR = 1.36 [1.16, 1.59]), and first-time fall (aHR = 1.34 [1.09, 1.65]).

CONCLUSIONS

COVID-19 increases the risk of mortality and other adverse health outcomes in dementia patients. These findings highlight the need for closer follow-up and management strategies for dementia patients post-COVID-19.

Sex-Specific HLA Alleles Contribute to the Modulation of COVID-19 Severity

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection, responsible for Coronavirus Disease 2019 (COVID-19), exhibits a spectrum of clinical manifestations, ranging from asymptomatic to severe pulmonary dysfunction or death. The variability in COVID-19 severity has largely been attributed to the host's genetic characteristics, suggesting a polygenic genetic architecture, without significant strong evidence of sex-related genetic differences. In this Italian retrospective case-control study, we investigated the association between COVID-19 severity (severe vs. asymptomatic/oligosymptomatic healed individuals) and HLA gene variants, analyzed by next-generation sequencing (NGS). We identified significant HLA alleles (according to the conventional nomenclature), SNPs and haplotypes in the HLA-B, -C, -F, -DQA1, -DRB1, and -DRB5 genes associated with COVID-19 severity. Interestingly, these variants showed biological sex-related effects. Also, we identified specific haplotypes associated with COVID-19 severity that are shared by different conventional HLA alleles, indicated here as "super-haplotypes". These haplotypes had a biological sex-specific impact on disease severity and markedly increased the risk of severe COVID-19 compared to the conventional HLA alleles (odds ratio of up to 15). Our data suggest that the revision of the current HLA nomenclature may help to identify variants with a stronger effect on disease susceptibility and that association studies could benefit from the stratification of patients by biological sex. If replicated in other disease models, these findings could help to define the functional diversity in immune response between sexes, also based on the HLA system. Finally, due to the global pandemic's mortality rate, we hypothesize here that SARS-CoV-2 may have acted as a natural selection trigger, leading to a drift in HLA allelic frequencies in the general population.

The immune-endocrine interplay in sex differential responses to viral infection and COVID-19

Men are at higher risk for developing severe COVID-19 than women, while women are at higher risk for developing post-acute sequelae of COVID-19 (PASC). This highlights the impact of sex differences on immune responses and clinical outcomes of acute COVID-19 or PASC. A dynamic immune-endocrine interface plays an important role in the development of effective immune responses impacting the control of viral infections. In this opinion article we discuss mechanisms underlying the transcriptional and epigenetic regulation of immune responses by sex hormones during viral infections. We propose that disruption of this delicate immune-endocrine interplay can result in worsened outcomes of viral disease. We also posit that insights into these immune mechanisms can propel the development of novel immunomodulatory interventions that leverage immune-endocrine pathways to treat viral infections.

The Physical Condition and Mental Health of Chinese College Students 3 Months After COVID-19 Recovery

Purpose: The study was to evaluate the physical condition and mental health of Chinese college student COVID-19 survivors, and to perform severity clustering of physical symptoms. Participants: The study finally included 1912 Chinese college students. Methods: A total of 33 symptoms including general physical symptoms, cardiopulmonary system, digestive system, neurological system, mental health and other symptoms were investigated three months after recovery from COVID-19, and these symptoms are identified using latent class analysis. Results: Three clusters were identified through latent class analysis: 13.2% with severe impairment (cluster 1), 27.2% with mild physical symptoms (cluster 2), and 59.5% with no or mild symptoms (cluster 3). The students who smoked, drank alcohol, did not exercise, or had a history of underlying medical conditions were more likely to have moderate to severe symptoms. Conclusions: Young COVID-19 survivors with a history of underlying diseases and unhealthy habits are more likely to have moderate to severe COVID-19 sequelae. Varying degrees of symptoms should be treated with different rehabilitation plans.

Sex differences in postacute infection syndromes

Postacute infection syndromes like Long Covid disproportionately affect females, differing in prevalence, symptoms, and potential causes from males. This Viewpoint highlights these sex differences, gaps in current understanding, and the critical need for sex-based research.

The Recurrence of Tracheobronchial Papillomatosis Following Prostate Cancer Diagnosis

Recurrent respiratory papillomatosis (RRP) is a challenging disease to manage, due to its highly recurring nature and the lack of a definitive treatment. It is characterized by the presence of benign papillomatous lesions caused by the human papillomavirus (HPV), which can pose a threat to the patient's airway patency and restrict their breathing ability. We present the case of a 64-year-old patient with a history of papillomas in the trachea and bronchi, treated with endobronchial cryotherapy. However, tracheal and bronchial papillomas recurred 10 years after the initial treatment and two years after the diagnosis of prostate cancer and hormonal therapy. We also engage in a discussion of the clinical and radiological features of RRP.

The role of androgens in migraine pathophysiology

Migraine affects ∼12 % of the worldwide population and is more prevalent in females, which suggests a role of sex hormones in migraine pathophysiology. Most studies have focused on estrogen and progesterone, and the involvement of androgens has been less studied. However, due to the recent advances in androgen interventions, which could advance new androgen-based migraine treatments, it is critical to better understand the role of androgens in migraine. Testosterone, the most studied androgen, was found to have an antinociceptive effect in various animal and human pain studies. Thus, it could also have a protective effect related to lower migraine severity and prevalence. In this review, we discuss studies examining the role of androgens on migraine-related symptoms in migraine animal models. Additionally, we summarize the results of human studies comparing androgen levels between patients with migraine and healthy controls, studies assessing the relationships between androgen levels and migraine severity, and intervention studies examining the impact of testosterone treatment on migraine severity. Many of the studies have limitations, however, the results suggest that androgens may have a minor effect on migraine. Still, it is possible that androgens are involved in migraine pathophysiology in a sub-group of patients such as in adolescents or postmenopausal women. We discuss potential mechanisms in which testosterone, as the main androgen tested, can impact migraine. These mechanisms range from the cellular level to systems and behavior and include the effect of testosterone on sensory neurons, the immune and vascular systems, the stress response, brain function, and mood. Lastly, we suggest future directions to advance this line of research.