Performance evaluation of the high-throughput quantitative Alinity m BK virus assay.

BK virus (BKV) infection or reactivation in immunocompromised individuals can lead to adverse health consequences including BKV-associated nephropathy (BKVAN) in kidney transplant patients and BKV-associated hemorrhagic cystitis (BKV-HC) in allogeneic hematopoietic stem cell transplant recipients. Monitoring BKV viral load plays an important role in post-transplant patient care. This study evaluates the performance of the Alinity m BKV Investigational Use Only (IUO) assay. The linearity of the Alinity m BKV IUO assay had a correlation coefficient of 1.000 and precision of SD ≤ 0.25 Log IU/mL for all panel members tested (2.0-7.3 Log IU/mL). Detection rate at 50 IU/mL was 100%. Clinical plasma specimens tested comparing Alinity m BKV IUO to ELITech MGB Alert BKV lab-developed test (LDT) on the Abbott m2000 platform using specimen extraction protocols for DNA or total nucleic acid (TNA) resulted in coefficient of correlation of 0.900 and 0.963, respectively, and mean bias of 0.03 and -0.54 Log IU/mL, respectively. Alinity m BKV IUO compared with Altona RealStar BKV and Roche cobas BKV assays demonstrated coefficient of correlation of 0.941 and 0.980, respectively, and mean bias of -0.47 and -0.31 Log IU/mL, respectively. Urine specimens tested on Alintiy m BKV IUO and ELITech BKV LDT using TNA specimen extraction had a coefficient of correlation of 0.917 and mean bias of 0.29 Log IU/mL. The Alinity m BKV IUO assay was performed with high precision across the dynamic range and correlated well with other available BKV assays. IMPORTANCE: BK virus (BKV) in transplant patients can lead to adverse health consequences. Viral load monitoring is important in post-transplant patient care. This study evaluates the Alinity m BKV assay with currently available assays.

Pitfalls of using polymerase chain reaction-based assays for JAK2 and CALR exon 9 variant testing in myeloproliferative neoplasms: Knowing when to go the extra mile!

OBJECTIVES: The BCR::ABL1 negative myeloproliferative neoplasms are sequentially tested for JAK2 p.V617F, followed by CALR exon 9 pathogenic variants. Historically, these variants were thought to be mutually exclusive. However, recent reports indicate coexisting JAK2 p.V617F and CALR exon 9 somatic variants. METHODS: Analysis of JAK2 p.V617F and CALR exon 9 variant was performed by polymerase chain reaction (PCR)-based assays. Subsequent testing was performed on the Genexus integrated sequencer (ThermoFisher) using the Oncomine myeloid assay GX v2. RESULTS: CALR exon 9 variants were positive in 3 cases, while 2 were positive for JAK2 p.V617F on PCR-based assays. Next-generation sequencing confirmed the JAK2 P.V617F status in all cases. CALR variants resulting in in-frame deletions were identified in 2 cases at a variant allele frequency of 52.16% and 50.91%, while the third case had an intronic CALR variant c.-48G>A at a variant allele frequency of 51.1%. Thus, CALR variants in all 3 cases were interpreted as potentially germline. Of the 228 cases that underwent JAK2 p.V617F and CALR cotesting in the past 2 years, only these 2 cases were positive for both JAK2 p.V617F and CALR exon 9 variants. CONCLUSIONS: These cases highlight the importance of understanding the pitfalls of molecular techniques in current practice.

Unique prenatal manifestations of biallelic NDUFAF5 variants: expansion of phenotype.

OBJECTIVE: Mitochondrial complex-I deficiency, nuclear type 16, is a rare autosomal recessive disorder caused by biallelic pathogenic variants in NDUFAF5 (C20orf7) (OMIM 618238). The aim of this study was to describe a severe early prenatal manifestation of this disorder, which was previously considered to occur only postnatally. METHODS: This was a multicenter retrospective case series including five fetuses from three non-related families, which shared common sonographic abnormalities, including brain cysts, corpus callosal malformations, non-immune hydrops fetalis and growth restriction. Genetic evaluation included chromosomal microarray analysis and exome sequencing. Two fetuses from the same family were also available for pathology examination, including electron microscopy. RESULTS: Chromosomal microarray analysis revealed no chromosomal abnormality in any of the tested cases. Trio exome sequencing demonstrated that three affected fetuses from three unrelated families were compound heterozygous or homozygous for likely pathogenic variants in NDUFAF5. No other causative variants were detected. The association between NDUFAF5 variants and fetal malformations was further confirmed by segregation analysis. Histological evaluation of fetal tissues and electron microscopy of the skeletal muscle, liver, proximal tubules and heart demonstrated changes that resembled postmortem findings in patients with mitochondrial depletion disorders as well as previously undescribed findings. CONCLUSIONS: Mitochondrial complex-I deficiency and specifically biallelic mutations in NDUFAF5 have a role in abnormal fetal development, presenting with severe congenital malformations. Mitochondrial complex-I disorders should be considered in the differential diagnosis of corpus callosal malformations and brain cysts, especially when associated with extracranial abnormalities, such as fetal growth restriction and non-immune hydrops fetalis. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Risk Estimation of Severe COVID-19 Based on Initial Biomarker Assessment Across Racial and Ethnic Groups.

CONTEXT.­: Disease courses in COVID-19 patients vary widely. Prediction of disease severity on initial diagnosis would aid appropriate therapy, but few studies include data from initial diagnosis. OBJECTIVE.­: To develop predictive models of COVID-19 severity based on demographic, clinical, and laboratory data collected at initial patient contact after diagnosis of COVID-19. DESIGN.­: We studied demographic data and clinical laboratory biomarkers at time of diagnosis, using backward logistic regression modeling to determine severe and mild outcomes. We used deidentified data from 14 147 patients who were diagnosed with COVID-19 by polymerase chain reaction SARS-CoV-2 testing at Montefiore Health System, from March 2020 to September 2021. We generated models predicting severe disease (death or more than 90 hospital days) versus mild disease (alive and fewer than 2 hospital days), starting with 58 variables, by backward stepwise logistic regression. RESULTS.­: Of the 14 147 patients, including Whites, Blacks, and Hispanics, 2546 (18%) patients had severe outcomes and 3395 (24%) had mild outcomes. The final number of patients per model varied from 445 to 755 because not all patients had all available variables. Four models (inclusive, receiver operating characteristic, specific, and sensitive) were identified as proficient in predicting patient outcomes. The parameters that remained in all models were age, albumin, diastolic blood pressure, ferritin, lactic dehydrogenase, socioeconomic status, procalcitonin, B-type natriuretic peptide, and platelet count. CONCLUSIONS.­: These findings suggest that the biomarkers found within the specific and sensitive models would be most useful to health care providers on their initial severity evaluation of COVID-19.

Prevalence and Factors Associated With Mycoplasma genitalium Infection in At-Risk Female Adolescents in Bronx County, New York.

BACKGROUND: Mycoplasma genitalium infection can adversely affect female reproductive health, but data are limited about prevalence and characteristics of the infection in female adolescents. We employed a sensitive assay to detect M. genitalium infection, and we describe its characteristics in a clinical sample of women younger than 21 years. METHODS: We recruited females aged 13 to 20 years in children's hospital clinics whose clinicians were testing for chlamydia/gonorrhea. Participants completed a questionnaire providing demographics, sexual history, and current symptoms. Urine/endocervical samples were tested for chlamydia/gonorrhea and partitioned for M. genitalium testing using Aptima M. genitalium assay. We reviewed records for the clinic visit to document examination, diagnosis, and results of sexually transmitted infection (STI) testing. We compared prevalence of M. genitalium infection by demographics, sexual history, symptoms, and signs. RESULTS: Of 153 participants mean age 18.07 ± 1.68 years, 58% self-identified as Hispanic, 27% Black, 64% straight/heterosexual, 27% bisexual, 1% gay/lesbian, 29% reported a prior STI diagnosis. Prevalence of M. genitalium was 11.1% (17/153), 13 of 17 were asymptomatic, 2 of 17 had pelvic inflammatory disease (PID), 3 of 17 coinfected with chlamydia or gonorrhea. Prevalence of chlamydia was 6.6% and of gonorrhea 2.6%. A logistic regression model indicated independent associations of bisexual orientation versus all other orientations (adjusted odds ratio [aOR], 4.80; 95% confidence interval [CI], 1.38-16.67), self-reported prior STI (aOR, 3.83; 95% CI, 1.10-13.37), and self-reported prior PID (aOR, 9.12; 95% CI, 1.02-81.72) with higher odds of M. genitalium infection. CONCLUSIONS: Findings suggest that in at-risk female populations younger than 21 years, M. genitalium is a prevalent STI and symptomatic adolescents may warrant testing and treatment. Further study of harms and benefits of testing asymptomatic bisexual female adolescents or those with prior STI/PID is needed.

Clinical utility of expanded non-invasive prenatal screening compared with chromosomal microarray analysis in over 8000 pregnancies without major structural anomaly.

OBJECTIVES: To evaluate the theoretical added value of two types of non-invasive prenatal screening (NIPS) expansions in pregnancies without major structural anomalies over the commonly used NIPS for chromosomes 13, 18, 21, X and Y (5-NIPS) and to compare them with the added value of chromosomal microarray analysis (CMA). METHODS: This was a retrospective cohort study based on CMA results of all pregnancies with normal ultrasound (including pregnancies with soft markers and with abnormal maternal serum screening) that had undergone amniocentesis between January 2013 to February 2022 and were registered in the database of the Rabin Medical Center genetic laboratory. We calculated the theoretical yield of 5-NIPS and compared the added value of expanded 5-NIPS for common microdeletions (1p36.3-1p36.2, 4p16.3-4p16.2, 5p15.3-5p15.1, 15q11.2-15q13.1 and 22q11.2) and genome-wide NIPS (including variants > 5 Mb) with the added value of CMA in the overall cohort and in subgroups according to indication for invasive testing. RESULTS: Among the 8605 examined pregnancies, 122 (1.4%) clinically significant CMA results were demonstrated. Of these, 44 (36.1%) were theoretically detectable on 5-NIPS, with the rates of 1.56% in 642 pregnancies with abnormal maternal serum screening, 0.63% in 318 pregnancies with soft markers, 0.62% in 4378 women with advanced maternal age (≥ 35 years) and 0.15% in 3267 women younger than 35 years. In addition to aneuploidies detectable on 5-NIPS, three (0.03%) cases detectable on 5-NIPS expanded for common microdeletions and nine (0.10%) cases detectable on genome-wide NIPS (excluding common microdeletions) were identified in the overall cohort. The added value of expanded NIPS tools over 5-NIPS was significantly lower compared with that of CMA, for the overall cohort and subgroups. CONCLUSIONS: 5-NIPS and even genome-wide NIPS would miss 63.9% and 54.1% of clinically significant CMA findings, respectively. The added value of 5-NIPS expanded to detect common microdeletions over 5-NIPS is about 0.035%, and the overall added value of genome-wide NIPS aimed at large CNVs is about 0.14%, both much lower compared with the added value of CMA (0.91%). These findings should assist healthcare practitioners in guiding couples towards informed decision-making regarding the choice between prenatal invasive testing and NIPS. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Genomic surveillance of SARS-CoV-2 during the first year of the pandemic in the Bronx enabled clinical and epidemiological inference.

The Bronx was an early epicenter of the COVID-19 pandemic in the USA. We conducted temporal genomic surveillance of 104 SARS-CoV-2 genomes across the Bronx from March October 2020. Although the local structure of SARS-CoV-2 lineages mirrored those of New York City and New York State, temporal sampling revealed a dynamic and changing landscape of SARS-CoV-2 genomic diversity. Mapping the trajectories of mutations, we found that while some became 'endemic' to the Bronx, other, novel mutations rose in prevalence in the late summer/early fall. Geographically resolved genomes enabled us to distinguish between cases of reinfection and persistent infection in two pediatric patients. We propose that limited, targeted, temporal genomic surveillance has clinical and epidemiological utility in managing the ongoing COVID pandemic.

Exome sequencing as first-tier test for fetuses with severe central nervous system structural anomalies.

OBJECTIVE: Prenatally detected central nervous system (CNS) anomalies present a diagnostic challenge. In this study, we compared the diagnostic yield of exome sequencing (ES) and chromosomal microarray analysis (CMA) in fetuses with a major CNS anomaly. METHODS: This was a retrospective study of 114 cases referred for genetic evaluation following termination of pregnancy (TOP) due to a major CNS anomaly detected on prenatal ultrasound. All fetuses were first analyzed by CMA. All CMA-negative cases were offered ES. CMA-positive cases were reanalyzed using ES to assess its ability to detect copy-number variants (CNVs). RESULTS: CMA identified a pathogenic or likely pathogenic (P/LP) CNV in 11/114 (10%) cases. Eighty-six CMA-negative cases were analyzed using ES, which detected P/LP sequence variants in 38/86 (44%). Among recurrent cases (i.e. cases with a previously affected pregnancy), the incidence of P/LP sequence variants was non-significantly higher compared with non-recurrent ones (12/19 (63%) vs 26/67 (39%); P = 0.06). Among the 38 cases with an ES diagnosis, 20 (53%) were inherited and carried a significant risk of recurrence. Reanalysis of 10 CMA-positive cases by ES demonstrated that the bioinformatics pipeline used for sequence variant analysis also detected all P/LP CNVs, as well as three previously known non-causative CNVs. CONCLUSIONS: In our study, ES provided a high diagnostic yield (> 50%) in fetuses with severe CNS structural anomalies, which may have been partly due to the highly selected case series that included post-TOP cases from a specialist referral center. These data suggest that ES may be considered as a first-tier test for the prenatal diagnosis of major fetal CNS anomalies, detecting both P/LP sequence variants and CNVs. This is of particular importance given the time constraints of an ongoing pregnancy and the risk of recurrence in future pregnancies. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Should COVID-19 symptoms be used to cohort patients in the emergency department? A retrospective analysis.

OBJECTIVE: To determine how cohorting patients based on presenting complaints affects risk of nosocomial infection in crowded Emergency Departments (EDs) under conditions of high and low prevalence of COVID-19. METHODS: This was a retrospective analysis of presenting complaints and PCR tests collected during the COVID-19 epidemic from 4 EDs from a large hospital system in Bronx County, NY, from May 1, 2020 to April 30, 2021. Sensitivity, specificity, positive and negative predictive value (PPV, NPV) were calculated for a symptom screen based on the CDC list of COVID-19 symptoms: fever/chills, shortness of breath/dyspnea, cough, muscle or body ache, fatigue, headache, loss of taste or smell, sore throat, nasal congestion/runny nose, nausea, vomiting, and diarrhea. PPV was calculated for varying values of prevalence. RESULTS: There were 80,078 visits with PCR tests. The sensitivity of the symptom screen was 64.7% (95% CI: 63.6, 65.8), specificity 65.4% (65.1, 65.8). PPV was 16.8% (16.5, 17.0) and NPV was 94.5% (94.4, 94.7) when the observed prevalence of COVID-19 in the ED over the year was 9.7%. The PPV of fever/chills, cough, body and muscle aches and nasal congestion/runny nose were each approximately 25% across the year, while diarrhea, nausea, vomiting and headache were less predictive, (PPV 4.7%-9.6%) The combinations of fever/chills, cough, muscle/body aches, and shortness of breath had PPVs of 40-50%. The PPV of the screen varied from 3.7% (3.6, 3.8) at 2% prevalence of COVID-19 to 44.3% (44.0, 44.7) at 30% prevalence. CONCLUSION: The proportion of patients with a chief complaint of COVID-19 symptoms and confirmed COVID-19 infection was exceeded by the proportion without actual infection. This was true when prevalence in the ED was as high as 30%. Cohorting of patients based on the CDC's list of COVID-19 symptoms will expose many patients who do not have COVID-19 to risk of nosocomially acquired COVID-19. EDs should not use the CDC list of COVID-19 symptoms as the only strategy to minimize exposure.

Extended storage of SARS-CoV-2 nasopharyngeal swabs does not negatively impact results of molecular-based testing across three clinical platforms.

With the global outbreak of COVID-19, the demand for testing rapidly increased and quickly exceeded the testing capacities of many laboratories. Clinical tests which receive CE (Conformité Européenne) and Food and Drug Administration (FDA) authorisations cannot always be tested thoroughly in a real-world environment. Here we demonstrate the long-term stability of nasopharyngeal swab specimens for SARS-CoV-2 molecular testing across three assays recently approved by the US FDA under Emergency Use Authorization. This study demonstrates that nasopharyngeal swab specimens can be stored under refrigeration or even ambient conditions for 21 days without clinically impacting the results of the real-time reverse transcriptase-PCR testing.

Fetal exome sequencing for isolated increased nuchal translucency: should we be doing it?

OBJECTIVE: To evaluate the utility of prenatal exome sequencing (ES) for isolated increased nuchal translucency (NT) and to investigate factors that increase diagnostic yield. DESIGN: Retrospective analysis of data from two prospective cohort studies. SETTING: Fetal medicine centres in the UK and USA. POPULATION: Fetuses with increased NT ≥3.5 mm at 11-14 weeks of gestation recruited to the Prenatal Assessment of Genomes and Exomes (PAGE) and Columbia fetal whole exome sequencing studies (n = 213). METHODS: We grouped cases based on (1) the presence of additional structural abnormalities at presentation in the first trimester or later in pregnancy, and (2) NT measurement at presentation. We compared diagnostic rates between groups using Fisher exact test. MAIN OUTCOME MEASURES: Detection of diagnostic genetic variants considered to have caused the observed fetal structural anomaly. RESULTS: Diagnostic variants were detected in 12 (22.2%) of 54 fetuses presenting with non-isolated increased NT, 12 (32.4%) of 37 fetuses with isolated increased NT in the first trimester and additional abnormalities later in pregnancy, and 2 (1.8%) of 111 fetuses with isolated increased NT in the first trimester and no other abnormalities on subsequent scans. Diagnostic rate also increased with increasing size of NT. CONCLUSIONS: The diagnostic yield of prenatal ES is low for fetuses with isolated increased NT but significantly higher where there are additional structural anomalies. Prenatal ES may not be appropriate for truly isolated increased NT but timely, careful ultrasound scanning to identify other anomalies emerging later can direct testing to focus where there is a higher likelihood of diagnosis.

Genomic surveillance of SARS-CoV-2 during the first year of the pandemic in the Bronx enabled clinical and epidemiological inference.

The Bronx was an early epicenter of the COVID-19 pandemic in the USA. We conducted temporal genomic surveillance of SARS-CoV-2 genomes across the Bronx from March-October 2020. Although the local structure of SARS-CoV-2 lineages mirrored those of New York City and New York State, temporal sampling revealed a dynamic and changing landscape of SARS-CoV-2 genomic diversity. Mapping the trajectories of variants, we found that while some became 'endemic' to the Bronx, other, novel variants rose in prevalence in the late summer/early fall. Geographically resolved genomes enabled us to distinguish between cases of reinfection and persistent infection in two pediatric patients. We propose that limited, targeted, temporal genomic surveillance has clinical and epidemiological utility in managing the ongoing COVID pandemic. One sentence summary: Temporally and geographically resolved sequencing of SARS-CoV-2 genotypes enabled surveillance of novel genotypes, identification of endemic viral variants, and clinical inferences, in the first wave of the COVID-19 pandemic in the Bronx.

Patterns of seroconversion for SARS-CoV2-IgG in patients with malignant disease and association with anticancer therapy.

Patients with cancer have been identified in several studies to be at high risk of developing severe COVID-19; however, rates of SARS-CoV-2 IgG seroconversion and its association with cancer types and anti-cancer therapy remain obscure. We conducted a retrospective cohort study in patients with cancer that underwent SARS-CoV-2 IgG testing. Two hundred and sixty-one patients with a cancer diagnosis underwent SARS-CoV-2 IgG testing and demonstrated a high rate of seroconversion (92%). However, significantly lower seroconversion was observed in patients with hematologic malignancies (82%), patients that received anti-CD-20 antibody therapy (59%) and stem cell transplant (60%). Interestingly, all 17 patients that received immunotherapy, including 16 that received anti-PD-1/PD-L1 monoclonal antibodies, developed SARS-Cov-2 IgG antibodies (100% seroconversion). These data show differential rates of seroconversion in specific patient groups and bear importance for clinical monitoring and vaccination strategies that are being developed to mitigate the COVID-19 pandemic.

Genetic associations of fatigue and other symptoms following breast cancer treatment: A prospective study.

BACKGROUND: Cancer-related fatigue, mood disturbances, pain and cognitive disturbance are common after adjuvant cancer therapy, but vary considerably between individuals despite common disease features and treatment exposures. A genetic basis for this variability was explored in a prospective cohort. METHODS: Physical and psychological health of women were assessed prospectively following therapy for early stage breast cancer with self-report questionnaires. Participation in a genetic association sub-study was offered. Indices for the key symptom domains of fatigue, pain, depression, anxiety, and neurocognitive difficulties were empirically derived by principal components analysis from end-treatment questionnaires, and then applied longitudinally. Genetic associations were sought with functional single nucleotide polymorphisms (SNPs) in pro- and anti-inflammatory cytokine genes - tumour necrosis factor (TNF)-α (-308 â€‹GG), interferon (IFN)-É£ (+874 â€‹TA), interleukin (IL)-10 (1082 â€‹GA and -592 CA), IL-6 (-174 â€‹GC), IL-1ß (-511 â€‹GA). RESULTS: Questionnaire data was available for 210 participants, of whom 111 participated in the genetic sub-study. As expected, symptom domain scores generally improved over several months following treatment completion. Tumour and adjuvant treatment related factors were unassociated with either severity or duration of the individual symptom domains, but severity of symptoms at end-treatment was strongly associated with duration for each domain (all p â€‹< â€‹0.05). In multivariable analyses, risk genotypes were independently associated with: fatigue with IL-6 -174 â€‹GG/GC and IL-10 -1082 GG; depression and anxiety with IL-10 -1082 AA; neurocognitive disturbance: TNF-α -308 GG; depression IL-1ß (all p â€‹< â€‹0.05). The identified SNPs also had cumulative effects in prolonging the time to recovery from the associated symptom domain. CONCLUSIONS: Genetic factors contribute to the severity and duration of common symptom domains after cancer therapy.

SARS-CoV-2 coinfection with additional respiratory virus does not predict severe disease: a retrospective cohort study.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) claimed over 4 million lives by July 2021 and continues to pose a serious public health threat. OBJECTIVES: Our retrospective study utilized respiratory pathogen panel (RPP) results in patients with SARS-CoV-2 to determine if coinfection (i.e. SARS-CoV-2 positivity with an additional respiratory virus) was associated with more severe presentation and outcomes. METHODS: All patients with negative influenza/respiratory syncytial virus testing who underwent RPP testing within 7 days of a positive SARS-CoV-2 test at a large, academic medical centre in New York were examined. Patients positive for SARS-CoV-2 with a negative RPP were compared with patients positive for SARS-CoV-2 and positive for a virus by RPP in terms of biomarkers, oxygen requirements and severe COVID-19 outcome, as defined by mechanical ventilation or death within 30 days. RESULTS: Of the 306 SARS-CoV-2-positive patients with RPP testing, 14 (4.6%) were positive for a non-influenza virus (coinfected). Compared with the coinfected group, patients positive for SARS-CoV-2 with a negative RPP had higher inflammatory markers and were significantly more likely to be admitted (P = 0.01). Severe COVID-19 outcome occurred in 111 (36.3%) patients in the SARS-CoV-2-only group and 3 (21.4%) patients in the coinfected group (P = 0.24). CONCLUSIONS: Patients infected with SARS-CoV-2 along with a non-influenza respiratory virus had less severe disease on presentation and were more likely to be admitted-but did not have more severe outcomes-than those infected with SARS-CoV-2 alone.

Weight gain and obesity rates in transgender and gender-diverse adults before and during hormone therapy.

BACKGROUND: Obesity rates and weight changes in adults on gender-affirming hormone therapy are lacking or limited by small sample sizes, duration, and location. SUBJECTS/METHODS: This longitudinal study followed the body mass index and body weights of 470 transgender and gender-diverse adult patients (247 transfeminine and 223 transmasculine; mean age, 27.8 years) seen at a Federally Qualified Health Center and an academic endocrinology practice, both in Washington DC USA. Body weight and body mass index were recorded at baseline and at multiple follow-up clinical visits up to 57 months after the initiation of gender-affirming hormone therapy. The outcomes of this study were the changes to body weight and obesity rates following hormone therapy. RESULTS: Within 2-4 months of starting gender-affirming hormone therapy, the mean body weight increased in the transmasculine group by 2.35 (1.15-3.55) kg and further increased beyond 34 months. Among the transfeminine group, the mean body weight was stable for the first 21 months of hormone therapy and then began to steadily increase, particularly in those under 30 years old. The prevalence of obesity at baseline was 25% in the transfeminine group and 39% in the transmasculine group. Following the initiation of hormone therapy, rates of obesity ranged from 42 to 52% among the transmasculine group and 21 to 30% among transfeminine group. Following 11-21 months of hormone therapy, weight gain ≥5 kg was seen among 21% of transfeminine individuals and 30% of transmasculine individuals. CONCLUSIONS: As compared with transfeminine individuals, transmasculine individuals have greater rates of obesity and weight gain before and during hormone therapy. Body weight and body mass index should be routinely monitored before and after the initiation of gender-affirming hormone therapy. Multidisciplinary weight-reduction interventions should be promoted where appropriate.