Missense mutations in PIEZO1, which encodes the Piezo1 mechanosensor protein, define Er red blood cell antigens.

Despite the identification of the high-incidence red cell antigen Era nearly 40 years ago, the molecular background of this antigen, together with the other 2 members of the Er blood group collection, has yet to be elucidated. Whole exome and Sanger sequencing of individuals with serologically defined Er alloantibodies identified several missense mutations within the PIEZO1 gene, encoding amino acid substitutions within the extracellular domain of the Piezo1 mechanosensor ion channel. Confirmation of Piezo1 as the carrier molecule for the Er blood group antigens was demonstrated using immunoprecipitation, CRISPR/Cas9-mediated gene knockout, and expression studies in an erythroblast cell line. We report the molecular bases of 5 Er blood group antigens: the recognized Era, Erb, and Er3 antigens and 2 novel high-incidence Er antigens, described here as Er4 and Er5, establishing a new blood group system. Anti-Er4 and anti-Er5 are implicated in severe hemolytic disease of the fetus and newborn. Demonstration of Piezo1, present at just a few hundred copies on the surface of the red blood cell, as the site of a new blood group system highlights the potential antigenicity of even low-abundance membrane proteins and contributes to our understanding of the in vivo characteristics of this important and widely studied protein in transfusion biology and beyond.

Syphilis Diagnosis After a Chlamydia, Gonorrhea, or HIV Diagnosis Among Reproductive-Aged Women in Baltimore, MD.

BACKGROUND: Syphilis incidence is increasing among reproductive-aged women, and previous sexually transmitted infections (STIs) are a risk factor for subsequent STIs. This study aimed to determine syphilis incidence after a chlamydia, gonorrhea, or HIV diagnosis, and identify characteristics associated with higher syphilis incidence rates among reproductive-aged women in 1 mid-Atlantic city. METHODS: A retrospective cohort of 85,113 chlamydia, gonorrhea, and HIV diagnoses occurring between 2009 and 2021 and among women aged 13 to 50 years was constructed using public health surveillance data. Cumulative incidence curves were estimated to examine time to early syphilis (i.e., primary, secondary, or early latent) diagnosis, and multivariable analyses determined incidence rate ratios by age (<25 vs. ≥25 years) and number of prior STI diagnoses (0 vs. ≥1) during the study period, stratified by STI. RESULTS: There were 85,113 reportable STI diagnoses and 646 syphilis diagnoses in the cohort. Approximately 1 of 150 chlamydia, 1 of 100 gonorrhea, and 1 of 50 HIV diagnoses were followed by a syphilis diagnosis within 5 years. Cumulative incidence of syphilis differed significantly by STI diagnosis ( P < 0.001). In multivariable analysis, syphilis incidence rates were higher among women diagnosed with ≥1 (vs. 0) prior STI regardless of STI type ( P < 0.05) and among women ≥25 (vs. <25) years old diagnosed with gonorrhea ( P < 0.05). CONCLUSIONS: There were significant differences in syphilis incidence by prior STI type, number of STIs, and age. Our data support targeted screening for syphilis among women with a history of STIs, parwomen with ≥1 prior STI diagnosis, and older women diagnosed with gonorrhea.

Syphilis positivity among men who have sex with men (MSM) with direct, indirect, and no linkage to female sex partners: Exploring the potential for sex network bridging in Baltimore City, MD.

BACKGROUND: Syphilis epidemics among women and men-who-have-sex-with-men (MSM) may be connected, but these connections are poorly understood. Using egocentric network data from a U.S. urban MSM cohort, we examined socio-demographics, behaviors, and syphilis positivity among MSM with (1) direct (MSM who report sex with women, MSMW); (2) indirect (MSM who only report male partners, some of whom are MSMW, MSMO/W); and (3) no (MSM who only report male partners and whose partners only have sex with men, MSMO/O) connection to women. METHODS: Sexually-active MSM aged 18-45 years were administered behavioral and network interviews (recall period: three months) and syphilis/HIV testing. Syphilis positivity was defined as RPR titer >1:8. Modified Poisson regression was used to test for differences across groups. RESULTS: Among 385 MSM, 14.5% were MSMW and 22.3% were MSMO/W. MSMW and MSMO/W were significantly more likely than MSMO/O to report sex behaviors associated with increased syphilis acquisition/transmission risk, including: > 2 sex partners [MSMW aPR:1.28 (0.98-1.68); MSMO/W aPR:1.35 (1.09-1.69)], concurrent sex partners [MSMW aPR:1.50 (1.17-1.92); MSMO/W aPR:1.39 (1.11-1.74)], and for MSMW only, transactional sex [aPR:2.07 (1.11-3.88)]. Syphilis positivity was 16.4% and was lower among MSMW (9.4%) and MSMO/W (14.1%) than MSMO/O (18.5%), but differences were not significant. CONCLUSIONS: There may be considerable connectivity between MSM and female sex partners that could facilitate syphilis transmission, and behaviors that increase acquisition/transmission risk among MSMW and MSMO/W may be distinct from MSMO/O. Future work should focus on examining the context and temporal patterns of sex partnerships among MSMW and MSMO/W.

Perceptions of a community-based HIV/STI testing program among Black gay, bisexual, and other MSM in Baltimore: a qualitative analysis.

Black gay, bisexual, and other men who have sex with men (GBM) are disproportionately affected by HIV and STIs. Safe Spaces 4 Sexual Health (SS4SH), a community-informed, status-neutral HIV/STI testing intervention combines online outreach via geo-social networking apps and social media with mobile van testing. During 2018-2019, we recruited 25 participants for interviews about their perceptions of SS4SH compared to clinic-based testing. Participants were aged 21-65 years (mean 35); 22 (88%) identified as Black/African American; 20 (80%) identified as gay; and 10 (40%) were living with HIV. Interviews were transcribed, coded, and analyzed using a modified thematic constant comparative approach. Five themes emerged; two related to perceptions of online outreach materials (participants were drawn to eye-catching and to-the-point messages and desired more diversity and representation in messages), and three related to preference for the mobile van (participants found SS4SH provided more comfort, more privacy/confidentiality, and increased accessibility and efficiency). GBM is increasingly using geo-social networking apps to meet sexual partners, and tailored online outreach has the potential to reach historically underserved populations. SS4SH is a barrier-reducing strategy that may serve as an entry to a status-neutral approach to services and help reduce stigma and normalize accessing HIV services.

Sexually Transmitted Infection Transmission Dynamics During the Coronavirus Disease 2019 (COVID-19) Pandemic Among Urban Gay, Bisexual, and Other Men Who Have Sex With Men.

BACKGROUND: The impact of coronavirus disease 2019 (COVID-19) mitigation measures on sexually transmitted infection (STI) transmission and racial disparities remains unknown. Our objectives were to compare sex and drug risk behaviors, access to sexual health services, and STI positivity overall and by race during the COVID-19 pandemic compared with pre-pandemic among urban sexual minority men (MSM). METHODS: Sexually active MSM aged 18-45 years were administered a behavioral survey and STI testing every 3-months. Participants who completed at least 1 during-pandemic (April 2020-December 2020) and 1 pre-pandemic study visit (before 13 March 2020) that occurred less than 6 months apart were included. Regression models were used to compare during- and pre-pandemic visit outcomes. RESULTS: Overall, among 231 MSM, reports of more than 3 sex partners declined(pandemic-1: adjusted prevalence ratio 0.68; 95% confidence interval: .54-.86; pandemic-2: 0.65, .51-.84; pandemic-3: 0.57, .43-.75), substance use decreased (pandemic-1: 0.75, .61-.75; pandemic-2: 0.62, .50-.78; pandemic-3: 0.61, .47-.80), and human immunodeficiency virus/preexposure prophylaxis care engagement (pandemic-1: 1.20, 1.07-1.34; pandemic-2: 1.24, 1.11-1.39; pandemic-3: 1.30, 1.16-1.47) increased. STI testing decreased (pandemic-1: 0.68, .57-.81; pandemic-2: 0.78, .67-.92), then rebounded (pandemic-3: 1.01, .87-1.18). Nei-ther Chlamydia (pandemic-2: 1.62, .75-3.46; pandemic-3: 1.13, .24-1.27) nor gonorrhea (pandemic-2: 0.87, .46 1.62; pandemic-3: 0.56, .24-1.27) positivity significantly changed during vs pre-pandemic. Trends were mostly similar among Black vs. non-Black MSM. CONCLUSIONS: We observed sustained decreases in STI risk behaviors but minimal change in STI positivity during compared with pre-pandemic. Our findings underscore the need for novel STI prevention strategies that can be delivered without in-person interactions.

International Society of Blood Transfusion Working Party on Red Cell Immunogenetics and Blood Group Terminology Report of Basel and three virtual business meetings: Update on blood group systems.

BACKGROUND AND OBJECTIVES: Under the ISBT, the Working Party (WP) for Red Cell Immunogenetics and Blood Group Terminology is charged with ratifying blood group systems, antigens and alleles. This report presents the outcomes from four WP business meetings, one located in Basel in 2019 and three held as virtual meetings during the COVID-19 pandemic in 2020 and 2021. MATERIALS AND METHODS: As in previous meetings, matters pertaining to blood group antigen nomenclature were discussed. New blood group systems and antigens were approved and named according to the serologic, genetic, biochemical and cell biological evidence presented. RESULTS: Seven new blood group systems, KANNO (defined numerically as ISBT 037), SID (038), CTL2 (039), PEL (040), MAM (041), EMM (042) and ABCC1 (043) were ratified. Two (039 and 043) were de novo discoveries, and the remainder comprised reported antigens where the causal genes were previously unknown. A further 15 blood group antigens were added to the existing blood group systems: MNS (002), RH (004), LU (005), DI (010), SC (013), GE (020), KN (022), JMH (026) and RHAG (030). CONCLUSION: The ISBT now recognizes 378 antigens, of which 345 are clustered within 43 blood group systems while 33 still have an unknown genetic basis. The ongoing discovery of new blood group systems and antigens underscores the diverse and complex biology of the red cell membrane. The WP continues to update the blood group antigen tables and the allele nomenclature tables. These can be found on the ISBT website (http://www.isbtweb.org/working-parties/red-cell-immunogenetics-and-blood-group-terminology/).

Basement membrane defects in CD151-associated glomerular disease.

BACKGROUND: CD151 is a cell-surface molecule of the tetraspanin family. Its lateral interaction with laminin-binding integrin ɑ3ß1 is important for podocyte adhesion to the glomerular basement membrane (GBM). Deletion of Cd151 in mice induces glomerular dysfunction, with proteinuria and associated focal glomerulosclerosis, disorganisation of GBM and tubular cystic dilation. Despite this, CD151 is not routinely screened for in patients with nephrotic-range proteinuria. We aimed to better understand the relevance of CD151 in human kidney disease. METHODS: Next-generation sequencing (NGS) was used to detect the variant in CD151. Electron and light microscopy were used to visualise the filtration barrier in the patient kidney biopsy, and immunoreactivity of patient red blood cells to anti-CD151/MER2 antibodies was performed. Further validation of the CD151 variant as disease-causing was performed in zebrafish using CRISPR-Cas9. RESULTS: We report a young child with nail dystrophy and persistent urinary tract infections who was incidentally found to have nephrotic-range proteinuria. Through targeted NGS, a novel, homozygous truncating variant was identified in CD151, a gene rarely reported in patients with nephrotic syndrome. Electron microscopy imaging of patient kidney tissue showed thickening of GBM and podocyte effacement. Immunofluorescence of patient kidney tissue demonstrated that CD151 was significantly reduced, and we did not detect immunoreactivity to CD151/MER2 on patient red blood cells. CRISPR-Cas9 depletion of cd151 in zebrafish caused proteinuria, which was rescued by injection of wild-type CD151 mRNA, but not CD151 mRNA containing the variant sequence. CONCLUSIONS: Our results indicate that a novel variant in CD151 is associated with nephrotic-range proteinuria and microscopic haematuria and provides further evidence for a role of CD151 in glomerular disease. Our work highlights a functional testing pipeline for future analysis of patient genetic variants. A higher resolution version of the Graphical abstract is available as Supplementary information.

Methamphetamine Use, Syphilis, and Specific Online Sex Partner Meeting Venues Are Associated With HIV Status Among Urban Black Gay and Bisexual Men Who Have Sex Men.

BACKGROUND: In the context of increasing syphilis rates, particularly among Black men who have sex men (MSM), the objectives were to determine the associations between methamphetamine (meth) use and syphilis and HIV positivity, and to identify sex partner meeting venues as potential intervention access points among Black MSM in a mid-Atlantic US city. METHODS: This study is an ongoing longitudinal cohort study. Participants were recruited from clinical and nonclinical settings and included sexually active MSM aged 18 to 45 years. The baseline visit included a behavioral survey and testing for syphilis, HIV, gonorrhea, and chlamydia. Logistic regression analyses were used for hypothesis testing. RESULTS: Among 359 MSM completing baseline, 74.4% (268) Black MSM were included; 31% (84) were aged 24 to 29 years, 43.7% (117) reported unprotected anal intercourse at last sex, and 15.3% (41) reported meth use in the past 3 months. Sixteen percent (43) had syphilis, 46.6% (125) were living with HIV, and 19.0% (51) had gonorrhea and/or chlamydia. Meth use was associated with sexual and drug risk behaviors and HIV, but not syphilis. In adjusted analyses, meth use increased the odds of HIV positivity by 6.43 (95% confidence interval, 2.30-17.98) and syphilis positivity by 2.57 (95% confidence interval, 1.23-5.37). Four online sex partner meeting venues were associated with meth use and HIV, whereas syphilis was associated with one. CONCLUSIONS: Among Black MSM, meth use and syphilis positivity were associated with more than 6-fold and almost 3-fold increased adjusted odds of HIV positivity, respectively. Four specific sex partner meeting venues may be important access points for HIV/sexually transmitted infection and substance use prevention.

Characterization of GYP*Mur and novel GYP*Bun-like hybrids in Thai blood donors reveals a qualitatively altered s antigen.

BACKGROUND AND OBJECTIVES: The Mi(a+) GP(B-A-B) hybrid phenotypes occur with a prevalence of 2%-23% across Southeast Asia. While the s antigen is alleged to be altered, no evidence for specific variants is known. Screening using a monoclonal IgM anti-s mistyped six S-s+ RBC units as S-s-. Further, alloanti-s was identified in an S+s+ patient. Our objective was to investigate the s antigen further. MATERIALS AND METHODS: DNA from 63 Thai blood donor samples PCR-positive for a GYP(B-A-B) hybrid was sequenced with primers spanning GYPB exons 3-4. Flow cytometry was used for semiquantitative analysis of s expression and correlated with the glycophorin genotype. RESULTS: DNA sequencing showed that GYP*Mur was carried by 56/63 samples (88·9%) of which 5/56 lacked normal GYPB: three of these were GYP*Mur homozygotes, one was a compound heterozygote carrying GYP*Mur and a GYP*Bun-like allele (designated GYP*Thai), and the fifth sample carried GYP*Mur and another GYP*Bun-like allele. Seven samples (7/63) were GYP*Thai heterozygotes. IgM monoclonal anti-s (P3BER) did not react with the s antigen carried by GP.Mur or GP.Bun, whereas two IgG anti-s showed enhanced reactivity. CONCLUSIONS: We confirmed that GYP*Mur is the most frequent variant in Thai blood donors and also identified GYP*Thai with a frequency of 1·1%. We showed that s antigen on Mi(a+) GP(B-A-B) hybrids is qualitatively altered and should be considered when selecting reagents for phenotyping where such hybrids are prevalent, endemically and in blood centres worldwide.

A large deletion spanning XG and GYG2 constitutes a genetic basis of the Xgnull phenotype, underlying anti-Xga production.

BACKGROUND: The PBDX/XG gene encoding the Xga blood group antigen was described in 1994, but the genetic determinant of XG expression on RBCs was reported only in 2018. However, the frequencies of Xg(a-) individuals could not explain the rarity of anti-Xga makers. We therefore sought to elucidate the molecular basis of the Xg(a-) phenotype in people producing anti-Xga . STUDY DESIGN AND METHODS: Two genomic DNA (gDNA) and 13 plasma-derived cell-free DNA (cfDNA) samples from anti-Xga makers were investigated (14 males and one female). PBDX/XG exon sequencing was attempted on one gDNA sample. Polymerase chain reaction assays were developed and bioinformatics used to define a suspected deletion in all samples. RESULTS: Investigation of one gDNA sample revealed a 114-kb deletion (esv2662319) on the X chromosome that spans XG exons 4 through 10 and the downstream GYG2 gene. A 3555-bp fragment bridging this deletion was amplified to confirm its presence. Another deletion-specific polymerase chain reaction of 714 bp enabled identification of esv2662319 in both gDNA samples and eight cfDNA samples while ruling it out in one cfDNA. Males were hemizygous for esv2662319 and the female likely homozygous. Four cfDNA sample results were inconclusive, probably due to poor sample quality. Sanger sequencing recognized the recombination junctions as a heterogeneous LTR6B sequence. CONCLUSION: We identified a large deletion on the X chromosome, resulting in a true, tissue-wide Xgnull phenotype. This deletion was found in 10 of 11 anti-Xga makers from which DNA could be amplified. One sample remained unexplained, indicating further heterogeneity to be explored.

International Society of Blood Transfusion Working Party on Red Cell Immunogenetics and Blood Group Terminology: Report of the Dubai, Copenhagen and Toronto meetings.

BACKGROUND AND OBJECTIVES: The International Society of Blood Transfusion (ISBT) Working Party for Red Cell Immunogenetics and Blood Group Terminology meets in association with the ISBT congress and has met three times since the last report: at the international meetings held in Dubai, United Arab Emirates, September 2016 and Toronto, Canada, June 2018; and at a regional congress in Copenhagen, Denmark, June 2017 for an interim session. METHODS: As in previous meetings, matters pertaining to blood group antigen nomenclature and classification were discussed. New blood group antigens were approved and named according to the serologic and molecular evidence presented. RESULTS AND CONCLUSIONS: Fifteen new blood group antigens were added to eight blood group systems. One antigen was made obsolete based on additional data. Consequently, the current total of blood group antigens recognized by the ISBT is 360, of which 322 are clustered within 36 blood groups systems. The remaining 38 antigens are currently unassigned to a known system. Clinically significant blood group antigens continue to be discovered, through serology/sequencing and/or recombinant or genomic technologies.

Clinical significance of antibodies to antigens in the ABO, MNS, P1PK, Rh, Lutheran, Kell, Lewis, Duffy, Kidd, Diego, Yt, and Xg blood group systems.

CONCLUSIONS: This report is part of a series reporting the proceedings from the International Society of Blood Transfusion (ISBT) Working Party on Immunohaematology Workshop on the Clinical Significance of Red Blood Cell Alloantibodies. The aim of the workshop was to review information regarding the clinical significance of alloantibodies to red blood cell antigens recognized by the ISBT. The first 12 systems will be covered in this report. It is understandable that many of the most clinically important antibodies are directed toward antigens found in the blood group systems discovered earlier in history. The ABO system was the first to be discovered and remains the most clinically important regarding transfusion.

Transfusions of least-incompatible blood with intravenous immunoglobulin plus steroids cover in two patients with rare antibody.

BACKGROUND: The therapeutic value of the use of intravenous immunoglobulin (IVIG) to correct anemia and thrombocytopenia as a result of immunologic causes (hemolytic disease of the fetus and newborn and fetal or neonatal alloimmune thrombocytopenia) have been well established. Few published papers exist regarding the use of IVIG in adult settings. We report two patients with clinically significant antibodies against high-incidence antigens, who were successfully transfused with incompatible red blood cells (RBCs), in conjunction with IVIG plus steroids and IVIG. CASE REPORTS: Case 1 was a 25-year-old patient (Hb SC) who was admitted with low hemoglobin (Hb) and low reticulocyte count. A diagnosis of parvovirus-induced RBC hypoplasia was made. The patient's sample contained anti-E, anti-N, and anti-U. The Hb decreased to 37 g/dL and urgent transfusion was provided with E-, N-, "least-incompatible" RBC units covered by IVIG and hydrocortisone. Case 2 was a 54-year-old patient who was admitted after a road traffic accident. Nonspecific weak antibody was detected. She received 6 units of least-incompatible RBCs. She was transferred to another hospital and received 2 least-incompatible units. Hb level decreased further and an additional unit was transfused. Samples were referred to the reference laboratory and strong anti-Jra detected. As there was clinical and laboratory evidence of hemolysis and Jr(a-) units were not available, IVIG was prescribed and least-incompatible units were transfused. RESULTS: There were no hemolytic transfusion reactions, hemolysis ceased, and anemia improved in both cases. CONCLUSION: Prophylaxis with IVIG plus steroids and IVIG should be considered as a therapeutic option when transfusion of incompatible units is necessary.

Identification of new KLF1 and LU alleles during the resolution of Lutheran typing discrepancies.

BACKGROUND: The Lu(b) antigen is expressed on red blood cells (RBCs) of the majority of individuals in all populations. Its absence in transfused patients may lead to alloantibody production and mild-to-moderate transfusion reactions, and in pregnancies to mild hemolytic disease of the fetus and newborn. This report describes the results of discrepancy resolution between apparent LU*A/LU*B or LU*B/LU*B genotypes and apparent Lu(b-) or Lu(b+ weak) phenotypes in one Asian and 10 Caucasian blood donors. STUDY DESIGN AND METHODS: Whole blood samples were analyzed by molecular methods to resolve discrepancies between Lu(b-) phenotypes detected by serology and Lu(b+) phenotypes predicted by genotyping. RBC agglutination assays were performed with commercial and patient antisera by tube or gel column methods. Genotyping was performed on commercial arrays that target the LU*A/LU*B polymorphism at Position c.230. The discrepancies were resolved by sequencing of genomic DNA and in some cases by sequencing of cloned DNA fragments. RESULTS: Eleven new alleles with coding sequence variants were identified, seven in the KLF1 gene, which are presumed to act dominantly to silence LU expression, and four in the LU gene itself. The alleles are KLF1*114delC, KLF1*298T, KLF1*304C,484insC, KLF1*304C,1000del2, KLF1*621G, KLF1*948delC, KLF1*1040A,1045delT, LU*B(559T,711T,714T), LU*B(611A,638T), LU*B(1049del2ins3), and LU*B(1306T,1340T,1671T,1742T). CONCLUSION: Besides confirming common phenotypes and detecting rare antigen-negative phenotypes, the use of molecular methods in blood donor typing can prompt the identification of new alleles through discrepancy resolution.

Recombinant blood group proteins facilitate the detection of alloantibodies to high-prevalence antigens and reveal underlying antibodies: results of an international study.

BACKGROUND: Alloantibodies to high-prevalence red blood cell (RBC) antigens are not easily identified by routine serologic techniques. This multicenter study was conducted to test the effectiveness of recombinant blood group proteins (rBGPs) at regional and international RBC reference laboratories. STUDY DESIGN AND METHODS: Single or mixed soluble rBGPs (Lu, Yt, Kn, JMH, Sc, Rg, Ch, Do, and Cr) were assessed for their ability to inhibit the reactivity of antibodies to specific antigens. Initially, the effect of rBGPs was validated by testing panels of well-characterized patient serum samples containing antibodies to high-prevalence antigens in the hemagglutination inhibition assay. Subsequently, the rBGPs were prospectively used for routine antibody identification and the results were compared to those obtained with RBC-based diagnostics. RESULTS: Panels of predefined antibodies to high-prevalence antigens were completely and specifically neutralized by the corresponding rBGP specificities. For prospective identification, antibodies to high-prevalence antigens (n = 62) were specifically inhibited by the corresponding rBGP specificities except for some Complement Receptor 1-related antibodies, which may be directed to epitopes not expressed on the truncated recombinant Kn. In 14 cases, additional clinically relevant alloantibodies were identified. In cross-matching, the rBGPs were successfully used to inhibit the reactivity of clinically irrelevant antibodies to high-prevalence antigens to determine compatibility between donor and recipient. CONCLUSION: rBGPs enable the identification of antibodies to high-prevalence antigens without the need for rare RBC reagents, which are often unavailable. Underlying antibodies can be reliably detected and cross-matching results validated, resulting in a more efficient blood supply for immunized patients.

Factors Associated with the Awareness of and Willingness to Use HIV Pre-exposure Prophylaxis Among Gay, Bisexual, and Other Men Who Have Sex with Men, Baltimore, MD, 2017-2019.

Pre-exposure prophylaxis (PrEP) is an effective tool in protecting persons from acquiring HIV infection through sex or injection drug use. However, awareness and willingness to use PrEP among Black gay, bisexual, and other men who have sex with men (BMSM) remain suboptimal compared to White MSM (WMSM) in the United States. Our aims were to (1) assess the factors associated with PrEP awareness and willingness to use PrEP among MSM and (2) compare the PrEP perceptions among BMSM versus non-Black MSM. Data were drawn from two cross-sectional behavioral surveys in Baltimore, MD: Behavioral Surveillance Research (BESURE) conducted in 2017, and Safe Spaces 4 Sexual Health (SS4SH), conducted in 2018 and 2019. Descriptive statistics were used to summarize the study population. We used Poisson regression models to identify variables associated with awareness of PrEP and willingness to use PrEP. PrEP perceptions were assessed via 13 items scored on a 5-point Likert scale. Finally, we conducted a post-hoc exploratory bivariate analysis of the relationship between PrEP perception and willingness to use PrEP, stratified by race/ethnicity. A total of 261 MSM participated in this study. Many of the participants were aware of PrEP (75.1%). Factors associated with greater PrEP awareness included having greater than a high school education (aRR 1.22, 95% CI 1.04, 1.43); and earning more than $25,000 annually (aRR 1.24, 95% CI 1.08, 1.42). Participants who had received money in exchange for sex one or more times were less likely to be aware of PrEP (aRR 0.59, 95% CI 0.36, 0.95). More than half of the participants were willing to use PrEP (55.3%). In bivariate and multivariable analyses, demographic or behavioral characteristics were not significantly associated with willingness to use PrEP. Higher agreement with the following statements was associated with lower willingness to use PrEP: "Having to take a pill every day is difficult" (RR 0.89, 95% CI 0.82-0.97) and, "I am concerned about the side effects of PrEP" (RR 0.89, 95% CI 0.82-0.96), and "PrEP is for people who have riskier sex lives than I do" (RR 0.86, 95% CI 0.78-0.95). Conversely, higher willingness to use PrEP was associated with comfortable having sex without a condom (RR 1.11, 95% CI 1.02-1.21), less anxious about sex (RR 1.12, 95% CI 1.02-1.24), and my friends think that I should take PrEP (RR 1.19, 95% CI 1.07-1.32). We found BMSM compared to non-Black MSM had higher mean scores related to taking a daily pill (p = 0.041), concerns about side effects (p = 0.012), concerns about people thinking they had HIV (p = 0.001), concerns about the financial costs of PrEP (p = 0.038) and caution when dealing with healthcare organizations/medical mistrust (p = 0.019). Perceptions with a statistically significant lower score among BMSM versus non-Black MSM included statements such as, comfortable having sex without a condom (p = 0.003) and less anxious about sex (p < 0.001). We conclude HIV prevention strategies, programs, and interventions should be cognizant of PrEP perceptions that facilitate or hinder PrEP uptake in Baltimore City, MD.

Study of the D-- phenotype reveals erythrocyte membrane alterations in the absence of RHCE.

Red cells with the D-- phenotype do not express the RHCE protein because of mutations in both alleles of the RHCE gene. At present, little is known of the effect this has on the normal function of erythrocytes. In this study a group of five families belonging to a nomadic tribe in Malaysia were identified as carriers of the D-- haplotype. Analysis of homozygous individuals' genomic DNA showed two separate novel mutations. In four of the families, RHCE exons 1, 9 and 10 were present, while the 5th family possessed RHCE exons 1-3 and 10. Analysis of cDNA revealed hybrid transcripts, suggesting a gene conversion event with RHD, consistent with previously reported D-- mutations. Immunoblotting analysis of D-- erythrocyte membrane proteins found that Rh-associated glycoprotein (RHAG) migrates with altered electrophoretic mobility on sodium dodecyl sulphate polyacrylamide gel electrophoresis, consistent with increased glycosylation. Total amounts of Rh polypeptide in D-- membranes were comparable with controls, indicating that the exalted D antigen displayed by D-- red cells may be associated with altered surface epitope presentation. The adhesion molecules CD44 and CD47 are significantly reduced in D--. Together these results suggest that absence of RHCE polypeptide alters the structure and packing of the band 3/Rh macrocomplex.