Trimodal single-cell profiling reveals a novel pediatric CD8αα+ T cell subset and broad age-related molecular reprogramming across the T cell compartment

Age-associated changes in the T cell compartment are well described. However, limitations of current single-modal or bimodal single-cell assays, including flow cytometry, RNA-seq (RNA sequencing) and CITE-seq (cellular indexing of transcriptomes and epitopes by sequencing), have restricted our ability to deconvolve more complex cellular and molecular changes. Here, we profile >300,000 single T cells from healthy children (aged 11-13 years) and older adults (aged 55-65 years) by using the trimodal assay TEA-seq (single-cell analysis of mRNA transcripts, surface protein epitopes and chromatin accessibility), which revealed that molecular programming of T cell subsets shifts toward a more activated basal state with age. Naive CD4+ T cells, considered relatively resistant to aging, exhibited pronounced transcriptional and epigenetic reprogramming. Moreover, we discovered a novel CD8αα+ T cell subset lost with age that is epigenetically poised for rapid effector responses and has distinct inhibitory, costimulatory and tissue-homing properties. Together, these data reveal new insights into age-associated changes in the T cell compartment that may contribute to differential immune responses.

Prior vaccination promotes early activation of memory T cells and enhances immune responses during SARS-CoV-2 breakthrough infection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection of vaccinated individuals is increasingly common but rarely results in severe disease, likely due to the enhanced potency and accelerated kinetics of memory immune responses. However, there have been few opportunities to rigorously study early recall responses during human viral infection. To better understand human immune memory and identify potential mediators of lasting vaccine efficacy, we used high-dimensional flow cytometry and SARS-CoV-2 antigen probes to examine immune responses in longitudinal samples from vaccinated individuals infected during the Omicron wave. These studies revealed heightened spike-specific responses during infection of vaccinated compared to unvaccinated individuals. Spike-specific cluster of differentiation (CD)4 T cells and plasmablasts expanded and CD8 T cells were robustly activated during the first week. In contrast, memory B cell activation, neutralizing antibody production and primary responses to nonspike antigens occurred during the second week. Collectively, these data demonstrate the functionality of vaccine-primed immune memory and highlight memory T cells as rapid responders during SARS-CoV-2 infection.

Prior vaccination enhances immune responses during SARS-CoV-2 breakthrough infection with early activation of memory T cells followed by production of potent neutralizing antibodies

SARS-CoV-2 infection of vaccinated individuals is increasingly common but rarely results in severe disease, likely due to the enhanced potency and accelerated kinetics of memory immune responses. However, there have been few opportunities to rigorously study early recall responses during human viral infection. To better understand human immune memory and identify potential mediators of lasting vaccine efficacy, we used high-dimensional flow cytometry and SARS-CoV-2 antigen probes to examine immune responses in longitudinal samples from vaccinated individuals infected during the Omicron wave. These studies revealed heightened Spike-specific responses during infection of vaccinated compared to unvaccinated individuals. Spike-specific CD4 T cells and plasmablasts expanded and CD8 T cells were robustly activated during the first week. In contrast, memory B cell activation, neutralizing antibody production, and primary responses to non-Spike antigens occurred during the second week. Collectively, these data demonstrate the functionality of vaccine-primed immune memory and highlight memory T cells as rapid responders during SARS-CoV-2 infection.

Efficient recall of Omicron-reactive B cell memory after a third dose of SARS-CoV-2 mRNA vaccine

We examined antibody and memory B cell responses longitudinally for ∼9-10 months after primary 2-dose SARS-CoV-2 mRNA vaccination and 3 months after a 3rd dose. Antibody decay stabilized between 6 and 9 months, and antibody quality continued to improve for at least 9 months after 2-dose vaccination. Spike- and RBD-specific memory B cells remained durable over time, and 40%-50% of RBD-specific memory B cells simultaneously bound the Alpha, Beta, Delta, and Omicron variants. Omicron-binding memory B cells were efficiently reactivated by a 3rd dose of wild-type vaccine and correlated with the corresponding increase in neutralizing antibody titers. In contrast, pre-3rd dose antibody titers inversely correlated with the fold-change of antibody boosting, suggesting that high levels of circulating antibodies may limit the added protection afforded by repeat short interval boosting. These data provide insight into the quantity and quality of mRNA-vaccine-induced immunity over time through 3 or more antigen exposures.

Signaling Through FcγRIIA and the C5a-C5aR Pathway Mediate Platelet Hyperactivation in COVID-19

Patients with COVID-19 present with a wide variety of clinical manifestations. Thromboembolic events constitute a significant cause of morbidity and mortality in patients infected with SARS-CoV-2. Severe COVID-19 has been associated with hyperinflammation and pre-existing cardiovascular disease. Platelets are important mediators and sensors of inflammation and are directly affected by cardiovascular stressors. In this report, we found that platelets from severely ill, hospitalized COVID-19 patients exhibited higher basal levels of activation measured by P-selectin surface expression and had poor functional reserve upon in vitro stimulation. To investigate this question in more detail, we developed an assay to assess the capacity of plasma from COVID-19 patients to activate platelets from healthy donors. Platelet activation was a common feature of plasma from COVID-19 patients and correlated with key measures of clinical outcome including kidney and liver injury, and APACHEIII scores. Further, we identified ferritin as a pivotal clinical marker associated with platelet hyperactivation. The COVID-19 plasma-mediated effect on control platelets was highest for patients that subsequently developed inpatient thrombotic events. Proteomic analysis of plasma from COVID-19 patients identified key mediators of inflammation and cardiovascular disease that positively correlated with in vitro platelet activation. Mechanistically, blocking the signaling of the FcγRIIa-Syk and C5a-C5aR pathways on platelets, using antibody-mediated neutralization, IgG depletion or the Syk inhibitor fostamatinib, reversed this hyperactivity driven by COVID-19 plasma and prevented platelet aggregation in endothelial microfluidic chamber conditions. These data identified these potentially actionable pathways as central for platelet activation and/or vascular complications and clinical outcomes in COVID-19 patients. In conclusion, we reveal a key role of platelet-mediated immunothrombosis in COVID-19 and identify distinct, clinically relevant, targetable signaling pathways that mediate this effect.

Efficient recall of Omicron-reactive B cell memory after a third dose of SARS-CoV-2 mRNA vaccine

Despite a clear role in protective immunity, the durability and quality of antibody and memory B cell responses induced by mRNA vaccination, particularly by a 3 ^rd dose of vaccine, remains unclear. Here, we examined antibody and memory B cell responses in a cohort of individuals sampled longitudinally for ∼9-10 months after the primary 2-dose mRNA vaccine series, as well as for ∼3 months after a 3 ^rd mRNA vaccine dose. Notably, antibody decay slowed significantly between 6- and 9-months post-primary vaccination, essentially stabilizing at the time of the 3 ^rd dose. Antibody quality also continued to improve for at least 9 months after primary 2-dose vaccination. Spike- and RBD-specific memory B cells were stable through 9 months post-vaccination with no evidence of decline over time, and ∼40-50% of RBD-specific memory B cells were capable of simultaneously recognizing the Alpha, Beta, Delta, and Omicron variants. Omicron-binding memory B cells induced by the first 2 doses of mRNA vaccine were boosted significantly by a 3rd dose and the magnitude of this boosting was similar to memory B cells specific for other variants. Pre-3 ^rd dose memory B cell frequencies correlated with the increase in neutralizing antibody titers after the 3 ^rd dose. In contrast, pre-3 ^rd dose antibody titers inversely correlated with the fold-change of antibody boosting, suggesting that high levels of circulating antibodies may limit reactivation of immunological memory and constrain further antibody boosting by mRNA vaccines. These data provide a deeper understanding of how the quantity and quality of antibody and memory B cell responses change over time and number of antigen exposures. These data also provide insight into potential immune dynamics following recall responses to additional vaccine doses or post-vaccination infections.

GRAPHICAL SUMMARY

mRNA vaccines induce durable immune memory to SARS-CoV-2 and variants of concern

The durability of immune memory after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) messenger RNA (mRNA) vaccination remains unclear. In this study, we longitudinally profiled vaccine responses in SARS-CoV-2–naïve and –recovered individuals for 6 months after vaccination. Antibodies declined from peak levels but remained detectable in most subjects at 6 months. By contrast, mRNA vaccines generated functional memory B cells that increased from 3 to 6 months postvaccination, with the majority of these cells cross-binding the Alpha, Beta, and Delta variants. mRNA vaccination further induced antigen-specific CD4+ and CD8+ T cells, and early CD4+ T cell responses correlated with long-term humoral immunity. Recall responses to vaccination in individuals with preexisting immunity primarily increased antibody levels without substantially altering antibody decay rates. Together, these findings demonstrate robust cellular immune memory to SARS-CoV-2 and its variants for at least 6 months after mRNA vaccination.

Rapid induction of antigen-specific CD4+ T cells is associated with coordinated humoral and cellular immunity to SARS-CoV-2 mRNA vaccination

SARS-CoV-2 mRNA vaccines have shown remarkable clinical efficacy, but questions remain about the nature and kinetics of T cell priming. We performed longitudinal antigen-specific T cell analyses on healthy SARS-CoV-2-naive and recovered individuals prior to and following mRNA prime and boost vaccination. Vaccination induced rapid antigen-specific CD4+ T cell responses in naive subjects after the first dose, whereas CD8+ T cell responses developed gradually and were variable in magnitude. Vaccine-induced Th1 and Tfh cell responses following the first dose correlated with post-boost CD8+ T cells and neutralizing antibodies, respectively. Integrated analysis revealed coordinated immune responses with distinct trajectories in SARS-CoV-2-naive and recovered individuals. Last, whereas booster vaccination improved T cell responses in SARS-CoV-2-naive subjects, the second dose had little effect in SARS-CoV-2-recovered individuals. These findings highlight the role of rapidly primed CD4+ T cells in coordinating responses to the second vaccine dose in SARS-CoV-2-naive individuals.

mRNA Vaccination Induces Durable Immune Memory to SARS-CoV-2 with Continued Evolution to Variants of Concern

SARS-CoV-2 mRNA vaccines have shown remarkable efficacy, especially in preventing severe illness and hospitalization. However, the emergence of several variants of concern and reports of declining antibody levels have raised uncertainty about the durability of immune memory following vaccination. In this study, we longitudinally profiled both antibody and cellular immune responses in SARS-CoV-2 naïve and recovered individuals from pre-vaccine baseline to 6 months post-mRNA vaccination. Antibody and neutralizing titers decayed from peak levels but remained detectable in all subjects at 6 months post-vaccination. Functional memory B cell responses, including those specific for the receptor binding domain (RBD) of the Alpha (B.1.1.7), Beta (B.1.351), and Delta (B.1.617.2) variants, were also efficiently generated by mRNA vaccination and continued to increase in frequency between 3 and 6 months post-vaccination. Notably, most memory B cells induced by mRNA vaccines were capable of cross-binding variants of concern, and B cell receptor sequencing revealed significantly more hypermutation in these RBD variant-binding clones compared to clones that exclusively bound wild-type RBD. Moreover, the percent of variant cross-binding memory B cells was higher in vaccinees than individuals who recovered from mild COVID-19. mRNA vaccination also generated antigen-specific CD8+ T cells and durable memory CD4+ T cells in most individuals, with early CD4+ T cell responses correlating with humoral immunity at later timepoints. These findings demonstrate robust, multi-component humoral and cellular immune memory to SARS-CoV-2 and current variants of concern for at least 6 months after mRNA vaccination. Finally, we observed that boosting of pre-existing immunity with mRNA vaccination in SARS-CoV-2 recovered individuals primarily increased antibody responses in the short-term without significantly altering antibody decay rates or long-term B and T cell memory. Together, this study provides insights into the generation and evolution of vaccine-induced immunity to SARS-CoV-2, including variants of concern, and has implications for future booster strategies.

Signaling through FcγRIIA and the C5a-C5aR pathway mediates platelet hyperactivation in COVID-19

Patients with COVID-19 present with a wide variety of clinical manifestations. Thromboembolic events constitute a significant cause of morbidity and mortality in patients infected with SARS-CoV-2. Severe COVID-19 has been associated with hyperinflammation and pre-existing cardiovascular disease. Platelets are important mediators and sensors of inflammation and are directly affected by cardiovascular stressors. In this report, we found that platelets from severely ill, hospitalized COVID-19 patients exhibit higher basal levels of activation measured by P-selectin surface expression, and have a poor functional reserve upon in vitro stimulation. Correlating clinical features to the ability of plasma from COVID-19 patients to stimulate control platelets identified ferritin as a pivotal clinical marker associated with platelet hyperactivation. The COVID-19 plasma-mediated effect on control platelets was highest for patients that subsequently developed inpatient thrombotic events. Proteomic analysis of plasma from COVID-19 patients identified key mediators of inflammation and cardiovascular disease that positively correlated with in vitro platelet activation. Mechanistically, blocking the signaling of the FcγRIIa-Syk and C5a-C5aR pathways on platelets, using antibody-mediated neutralization, IgG depletion or the Syk inhibitor fostamatinib, reversed this hyperactivity driven by COVID-19 plasma and prevented platelet aggregation in endothelial microfluidic chamber conditions, thus identifying these potentially actionable pathways as central for platelet activation and/or vascular complications in COVID-19 patients. In conclusion, we reveal a key role of platelet-mediated immunothrombosis in COVID-19 and identify distinct, clinically relevant, targetable signaling pathways that mediate this effect. These studies have implications for the role of platelet hyperactivation in complications associated with SARS-CoV-2 infection.

COVER ILLUSTRATION

ONE-SENTENCE SUMMARY

The FcγRIIA and C5a-C5aR pathways mediate platelet hyperactivation in COVID-19.

Distinct antibody and memory B cell responses in SARS-CoV-2 naïve and recovered individuals following mRNA vaccination

Novel mRNA vaccines for SARS-CoV-2 have been authorized for emergency use. Despite their efficacy in clinical trials, data on mRNA vaccine-induced immune responses are mostly limited to serological analyses. Here, we interrogated antibody and antigen-specific memory B cells over time in 33 SARS-CoV-2 naïve and 11 SARS-CoV-2 recovered subjects. SARS-CoV-2 naïve individuals required both vaccine doses for optimal increases in antibodies, particularly for neutralizing titers against the B.1.351 variant. Memory B cells specific for full-length spike protein and the spike receptor binding domain (RBD) were also efficiently primed by mRNA vaccination and detectable in all SARS-CoV-2 naive subjects after the second vaccine dose, though the memory B cell response declined slightly with age. In SARS-CoV-2 recovered individuals, antibody and memory B cell responses were significantly boosted after the first vaccine dose; however, there was no increase in circulating antibodies, neutralizing titers, or antigen-specific memory B cells after the second dose. This robust boosting after the first vaccine dose strongly correlated with levels of pre-existing memory B cells in recovered individuals, identifying a key role for memory B cells in mounting recall responses to SARS-CoV-2 antigens. Together, our data demonstrated robust serological and cellular priming by mRNA vaccines and revealed distinct responses based on prior SARS-CoV-2 exposure, whereby COVID-19 recovered subjects may only require a single vaccine dose to achieve peak antibody and memory B cell responses. These findings also highlight the utility of defining cellular responses in addition to serologies and may inform SARS-CoV-2 vaccine distribution in a resource-limited setting.

Seasonal human coronavirus antibodies are boosted upon SARS-CoV-2 infection but not associated with protection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread within the human population. Although SARS-CoV-2 is a novel coronavirus, most humans had been previously exposed to other antigenically distinct common seasonal human coronaviruses (hCoVs) before the coronavirus disease 2019 (COVID-19) pandemic. Here, we quantified levels of SARS-CoV-2-reactive antibodies and hCoV-reactive antibodies in serum samples collected from 431 humans before the COVID-19 pandemic. We then quantified pre-pandemic antibody levels in serum from a separate cohort of 251 individuals who became PCR-confirmed infected with SARS-CoV-2. Finally, we longitudinally measured hCoV and SARS-CoV-2 antibodies in the serum of hospitalized COVID-19 patients. Our studies indicate that most individuals possessed hCoV-reactive antibodies before the COVID-19 pandemic. We determined that ∼20% of these individuals possessed non-neutralizing antibodies that cross-reacted with SARS-CoV-2 spike and nucleocapsid proteins. These antibodies were not associated with protection against SARS-CoV-2 infections or hospitalizations, but they were boosted upon SARS-CoV-2 infection.

Longitudinal Analysis Reveals Distinct Antibody and Memory B Cell Responses in SARS-CoV2 Naïve and Recovered Individuals Following mRNA Vaccination

Novel mRNA vaccines for SARS-CoV2 have been authorized for emergency use and are currently being administered to millions of individuals worldwide. Despite their efficacy in clinical trials, there is limited data on vaccine-induced immune responses in individuals with a prior SARS-CoV2 infection compared to SARS-CoV2 naïve subjects. Moreover, how mRNA vaccines impact the development of antibodies as well as memory B cells in COVID-19 experienced versus COVID-19 naïve subjects remains poorly understood. In this study, we evaluated antibody responses and antigen-specific memory B cell responses over time in 33 SARS-CoV2 naïve and 11 SARS-CoV2 recovered subjects. mRNA vaccination induced significant antibody and memory B cell responses against full-length SARS-CoV2 spike protein and the spike receptor binding domain (RBD). SARS-CoV2 naïve individuals benefitted from both doses of mRNA vaccine with additional increases in antibodies and memory B cells following booster immunization. In contrast, SARS-CoV2 recovered individuals had a significant immune response after the first dose with no increase in circulating antibodies or antigen-specific memory B cells after the second dose. Moreover, the magnitude of the memory B cell response induced by vaccination was lower in older individuals, revealing an age-dependence to mRNA vaccine-induced B cell memory. Side effects also tended to associate with post-boost antibody levels, but not with post-boost memory B cells, suggesting that side effect severity may be a surrogate of short-term antibody responses. The frequency of pre-vaccine antigen-specific memory B cells in SARS-CoV2 recovered individuals strongly correlated with post-vaccine antibody levels, supporting a key role for memory B cells in humoral recall responses to SARS-CoV2. This observation may have relevance for future booster vaccines and for responses to viral variants that partially escape pre-existing antibodies and require new humoral responses to be generated from memory B cells. Finally, post-boost antibody levels were not correlated with post-boost memory responses in SARS-CoV2 naïve individuals, indicating that short-term antibody levels and memory B cells are complementary immunological endpoints that should be examined in tandem when evaluating vaccine response. Together, our data provide evidence of both serological response and immunological memory following mRNA vaccination that is distinct based on prior SARS-CoV2 exposure. These findings may inform vaccine distribution in a resource-limited setting.

Seasonal human coronavirus antibodies are boosted upon SARS-CoV-2 infection but not associated with protection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread within the human population. Although SARS-CoV-2 is a novel coronavirus, most humans had been previously exposed to other antigenically distinct common seasonal human coronaviruses (hCoVs) before the COVID-19 pandemic. Here, we quantified levels of SARS-CoV-2-reactive antibodies and hCoV-reactive antibodies in serum samples collected from 204 humans before the COVID-19 pandemic. We then quantified pre-pandemic antibody levels in serum from a separate cohort of 252 individuals who became PCR-confirmed infected with SARS-CoV-2. Finally, we longitudinally measured hCoV and SARS-CoV-2 antibodies in the serum of hospitalized COVID-19 patients. Our studies indicate that most individuals possessed hCoV-reactive antibodies before the COVID-19 pandemic. We determined that ~23% of these individuals possessed non-neutralizing antibodies that cross-reacted with SARS-CoV-2 spike and nucleocapsid proteins. These antibodies were not associated with protection against SARS-CoV-2 infections or hospitalizations, but paradoxically these hCoV cross-reactive antibodies were boosted upon SARS-CoV-2 infection.

Deep immune profiling of COVID-19 patients reveals distinct immunotypes with therapeutic implications

Coronavirus disease 2019 (COVID-19) is currently a global pandemic, but human immune responses to the virus remain poorly understood. We used high-dimensional cytometry to analyze 125 COVID-19 patients and compare them with recovered and healthy individuals. Integrated analysis of ~200 immune and ~50 clinical features revealed activation of T cell and B cell subsets in a proportion of patients. A subgroup of patients had T cell activation characteristic of acute viral infection and plasmablast responses reaching >30% of circulating B cells. However, another subgroup had lymphocyte activation comparable with that in uninfected individuals. Stable versus dynamic immunological signatures were identified and linked to trajectories of disease severity change. Our analyses identified three immunotypes associated with poor clinical trajectories versus improving health. These immunotypes may have implications for the design of therapeutics and vaccines for COVID-19.

SARS-CoV-2 seroprevalence among parturient women in Philadelphia

Limited data are available for pregnant women affected by SARS-CoV-2. Serological tests are critically important for determining SARS-CoV-2 exposures within both individuals and populations. We validated a SARS-CoV-2 spike receptor binding domain serological test using 834 pre-pandemic samples and 31 samples from COVID-19 recovered donors. We then completed SARS-CoV-2 serological testing of 1,293 parturient women at two centers in Philadelphia from April 4 to June 3, 2020. We found 80/1,293 (6.2%) of parturient women possessed IgG and/or IgM SARS-CoV-2-specific antibodies. We found race/ethnicity differences in seroprevalence rates, with higher rates in Black/non-Hispanic and Hispanic/Latino women. Of the 72 seropositive women who also received nasopharyngeal polymerase chain reaction testing during pregnancy, 46 (64%) were positive. Continued serologic surveillance among pregnant women may inform perinatal clinical practices and can potentially be used to estimate exposure to SARS-CoV-2 within the community.

Comprehensive mapping of immune perturbations associated with severe COVID-19

Although critical illness has been associated with SARS-CoV-2-induced hyperinflammation, the immune correlates of severe COVID-19 remain unclear. Here, we comprehensively analyzed peripheral blood immune perturbations in 42 SARS-CoV-2 infected and recovered individuals. We identified extensive induction and activation of multiple immune lineages, including T cell activation, oligoclonal plasmablast expansion, and Fc and trafficking receptor modulation on innate lymphocytes and granulocytes, that distinguished severe COVID-19 cases from healthy donors or SARS-CoV-2-recovered or moderate severity patients. We found the neutrophil to lymphocyte ratio to be a prognostic biomarker of disease severity and organ failure. Our findings demonstrate broad innate and adaptive leukocyte perturbations that distinguish dysregulated host responses in severe SARS-CoV-2 infection and warrant therapeutic investigation.

SARS-CoV-2 Seroprevalence Among Parturient Women

Limited data are available for pregnant women affected by SARS-CoV-2. Serological tests are critically important to determine exposure and immunity to SARS-CoV-2 within both individuals and populations. We completed SARS-CoV-2 serological testing of 1,293 parturient women at two centers in Philadelphia from April 4 to June 3, 2020. We tested 834 pre-pandemic samples collected in 2019 and 15 samples from COVID-19 recovered donors to validate our assay, which has a ~1% false positive rate. We found 80/1,293 (6.2%) of parturient women possessed IgG and/or IgM SARS-CoV-2-specific antibodies. We found race/ethnicity differences in seroprevalence rates, with higher rates in Black/non-Hispanic and Hispanic/Latino women. Of the 72 seropositive women who also received nasopharyngeal polymerase chain reaction testing during pregnancy, 46 (64%) were positive. Continued serologic surveillance among pregnant women may inform perinatal clinical practices and can potentially be used to estimate seroprevalence within the community.

Deep immune profiling of COVID-19 patients reveals patient heterogeneity and distinct immunotypes with implications for therapeutic interventions

COVID-19 has become a global pandemic. Immune dysregulation has been implicated, but immune responses remain poorly understood. We analyzed 71 COVID-19 patients compared to recovered and healthy subjects using high dimensional cytometry. Integrated analysis of ~200 immune and >30 clinical features revealed activation of T cell and B cell subsets, but only in some patients. A subgroup of patients had T cell activation characteristic of acute viral infection and plasmablast responses could reach >30% of circulating B cells. However, another subgroup had lymphocyte activation comparable to uninfected subjects. Stable versus dynamic immunological signatures were identified and linked to trajectories of disease severity change. These analyses identified three "immunotypes" associated with poor clinical trajectories versus improving health. These immunotypes may have implications for therapeutics and vaccines.

An interesting case of adenoviral hepatitis in a cardiac transplant recipient

Adenoviral infections are commonly described in pediatric transplant populations. However, much less information is available regarding the incidence of infection and clinical spectrum of disease in adult transplant recipients. Moreover, this infection usually manifests as involvement of the transplanted organ in one pathologic form or the other, in addition to other systemic manifestations. We present a case of adenoviral infection of a nontransplanted organ in a solid organ transplant recipient.

The CASE adherence index: A novel method for measuring adherence to antiretroviral therapy

The Center for Adherence Support Evaluation (CASE) Adherence Index, a simple composite measure of self-reported antiretroviral therapy (ART) adherence, was compared to a standard three-day self-reported adherence measure among participants in a longitudinal, prospective cross-site evaluation of 12 adherence programs throughout the United States. The CASE Adherence Index, consisting of three unique adherence questions developed for the cross-site study, along with a three-day adherence self-report were administered by interviews every three months over a one-year period. Data from the three cross-site adherence questions (individually and in combination) were compared to three -day self-report data and HIV RNA and CD4 outcomes in cross-sectional analyses. The CASE Adherence Index correlated strongly with the three-day self-reported adherence data (p < 0.001) and was more strongly associated with HIV outcomes, including a 1-log decline in HIV RNA level (maximum OR = 2.34; p < 0.05), HIV RNA < 400 copies/ml (maximum OR = 2.33; p < 0.05) and performed as well as the three-day self-report when predicting CD4 count status. Participants with a CASE Index score >10 achieved a 98 cell mean increase in CD4 count over 12 months, compared to a 41 cell increase for those with scores < or =10 (p < 0.05). The CASE Adherence Index is an easy to administer instrument that provides an alternative method for assessing ART adherence in clinical settings.

Analytical laboratory quality: Part II. Analytical method validation

The most important objective to be met by an analytical testing facility is to have confidence in the data it generates. Most laboratories devote considerable energy to insure that test methods are appropriate, instruments are operational, and the training of analysts is adequate. Experienced scientists will design suitable internal controls in each analysis to confirm the success of a test. Good laboratory managers will monitor the status of facility operations to detect negative trends in the routine performance of instruments, methods, or analysts. Validation, a study designed to insure that a system is suitable for its intended use, is another mechanism that a facility can utilized to enhance confidence that the methods and instruments being used are capable of generating valid results. Additionally, using a validation protocol as a training tool can serve as an excellent manager/mentor mechanism for each type of technology employed in the laboratory. Finally, the generic validation of representative (surrogate) materials allows ongoing assessment of performance attributes independently from the wide variety specific sample types seen by core facilities.

Stress and burnout in oncology

This article identifies the professional stressors experienced by nurses, house staff, and medical oncologists and examines the effect of stress and personality attributes on burnout scores. A survey was conducted of 261 house staff, nurses, and medical oncologists in a cancer research hospital, and oncologists in outside clinical practices. It measured burnout, psychological distress, and physical symptoms. Each participant completed a questionnaire that quantified life stressors, personality attributes, burnout, psychological distress, physical symptoms, coping strategies, and social support. The results showed that house staff experienced the greatest burnout. They also reported greater emotional exhaustion, a feeling of emotional distance from patients, and a poorer sense of personal accomplishment. Negative work events contributed significantly to level of burnout; however, having a "hardy" personality helped to alleviate burnout. Nurses reported more physical symptoms than house staff and oncologists. However, they were less emotionally distant from patients. Women reported a lower sense of accomplishment and greater distress. The four most frequent methods of relaxing were talking to friends, using humor, drinking coffee or eating, and watching television. One unexpected finding was that the greater the perception of oneself as religious, the lower the level of burnout. Thus, while the rewards of working in oncology are usually sufficient to keep nurses and doctors in the field, they also experience burnout symptoms that vary by gender and personal attributes. House staff are most stressed and report the greatest and most severe symptoms of stress. Interventions are needed that address the specific problems of each group.

Gestational age-dependent expression of IL-10 and its receptor in human placental tissues and isolated cytotrophoblasts

Control of antifetal immune responses is thought to be regulated locally by the placenta. Because the physiologic programming of the placenta across gestation is likely to influence the local immunity, we hypothesize that a potent anti-inflammatory cytokine such as IL-10 may be produced in a gestational age-dependent manner. In the present study, we examined the expression of IL-10 and its receptor in placental explants or freshly isolated cytotrophoblasts from different gestational ages and compared it with the expression profiles of other cytokines. First and second trimester placental tissues from normal pregnancies predominantly expressed IL-10, whereas the levels of IL-2, IL-4, and IFN-gamma were mostly below detection throughout pregnancy. The expression of IL-10, but not its receptor, diminished significantly in term placental tissues collected "before" the onset of labor and did not change appreciably "after" labor. On the other hand, TNF-alpha and IL-1beta were significantly up-regulated in response to labor-associated conditions. IL-10 expression was transcriptionally attenuated at term as observed in cytotrophoblasts. In contrast to the placental cytokine milieu, autologous PBMCs, when activated with PHA, secreted significant amounts of IL-2, IL-4, IL-10, and IFN-gamma, albeit with a statistically significantly enhanced IL-10 production in first trimester compared with age-matched nonpregnant women. These data suggest that IL-10 is expressed in the placenta in a gestational age-dependent manner and that its down-regulation at term may be an important mechanism underlying the subtle changes associated with parturition.

Labor-associated changes in Fas ligand expression and function in human placenta

Fas ligand (FasL)-dependent apoptosis has been implicated in the control of tissue-damaging inflammatory responses in several immune privileged sites. Here, we present data demonstrating that FasL is expressed on human trophoblast cells throughout pregnancy and transduces growth inhibitory/death signals in cells bearing its receptor, Fas (CD95). Immunohistochemical analysis detected FasL-positive staining in the trophoblast layer of villi of first- and second-trimester and term (no labor) placental tissues, as well as in freshly isolated cytotrophoblasts representing these gestational ages. In contrast, term placental tissues and cytotrophoblasts from labor-associated deliveries exhibited significantly reduced FasL expression, suggesting that parturition altered the characteristics of trophoblast cells. FasL-specific immunoblotting of cytotrophoblast cell lysates further confirmed these results. To assess the functionality of FasL expressed on cytotrophoblasts, we co-cultured these cells with Fas-bearing Jurkat T cells. Cytotrophoblasts from early pregnancy, or term with no labor, significantly inhibited growth in Jurkat cells, evident even at a 1:1 effector:target cell ratio, as determined by the incorporation of [3H]thymidine. Similar results were obtained when a FasL-positive colon carcinoma cell line, SW620, was used in place of cytotrophoblasts. In contrast, term cytotrophoblasts from labor deliveries exhibited poor FasL expression and were quantitatively much less proficient in inhibiting [3H]thymidine incorporation in Jurkat cells. These data indicate that FasL could participate in modulating the inflammatory responses associated with labor and suggest intrinsic molecular differences in the placental microenvironment before and after labor .

Spouse support, coping, and mood among individuals with cancer

A model of the relations between spouse support, coping, and positive and negative mood was examined with 221 individuals with cancer using LISREL analyses. A moderating effect for patient life expectancy was predicted for disease prognosis. Results indicated that spouse criticism was associated with negative mood indirectly through avoidant coping strategies, and spouse support was associated with positive mood indirectly through positively-focused coping. Results did not support a moderating influence for life expectancy upon the association between spouse behaviors and patient coping. The results of this study are discussed in terms of their implications for psychosocial interventions to reduce psychological distress among individuals with cancer.

Spousal negative responses to cancer patients: the role of social restriction, spouse mood, and relationship satisfaction

This cross-sectional study examined perceptions of spousal negative behaviors in 219 cancer patients. A mediational model was proposed to explain why a spouse might respond negatively to an ill partner because of greater restriction on activities as functional impairment increases. A moderating effect of the spouse's marital satisfaction assessed 3 months before other study measures was also proposed. Results provided support for the proposed model. The relationship between increasing patient functional impairment and spousal negative behaviors was medicated by greater restriction in spouse activities, as well as spousal negative mood. A marginally significant moderating effect for marital satisfaction was found. Although these results must be replicated with a prospective study, the findings begin to shed light on why spouses might respond in negative ways to an ill partner.

Matrilineal inheritance of complex I dysfunction in a multigenerational Parkinson's disease family

Recent data suggesting complex I dysfunction in Parkinson's disease (PD) arises from mitochondrial DNA (mtDNA) mutation does not conclusively answer whether the responsible genetic lesion is inherited (primary) or somatic (secondary). To address this question, we identified a family in which multiple members over three generations are affected with PD through exclusively maternal lines. Cytoplasmic hybrids (cybrids) were created for 15 family members over two generations by transferring each individual's mtDNA to mtDNA-depleted human neuroblastoma cells. Eight of the 15 cybrid lines contained mtDNA obtained from maternally descended family members and seven contained mtDNA from paternally descended family members. After 6 weeks of culture, cybrid cell lines were assayed for complex I activity and oxidative stress, and mitochondrial morphology was analyzed by electron microscopy. Compared with the cybrid lines containing mtDNA from paternal descendants, cybrid lines containing mtDNA from maternal descendants had lower complex I activity, increased reactive oxygen species production, increased radical scavenging enzyme activities, and more abnormal mitochondrial morphologic features. These findings were present in cybrid lines containing mtDNA from maternal descendants with PD as well as in currently asymptomatic young maternal descendants, and support a precedent for inherited mtDNA mutation in some persons with PD.

Supportive and negative responses in the partner relationship: their association with psychological adjustment among individuals with cancer

This study examined the association between positive and negative aspects of spouse responses and psychological adjustment among 158 individuals with cancer. Two contextual variables, gender and disease-related functional impairment, were taken into account when examining the association between spouse responses and patient psychological distress and well-being. Results indicated that negative aspects of close relationships played a comparatively stronger role than positive aspects in their associations with both psychological distress and well-being. For negative spouse responses, patient gender did not moderate the effects of these responses upon psychological outcomes. For positive aspects of spouse support, both gender and functional disability moderated the association between spouse support and psychological outcomes. These findings are integrated with the general literature on positive and negative aspects of close relationships. Implications for clinical interventions are also discussed.

A field-gradient coil using concentric return paths

An approach to transverse field-gradient coil design is presented which locates all current elements in planes perpendicular to the main magnetic field. The linear volume of the resulting coil structure can be made to extend nearly to both ends of the coil. This design is based on forming a concentric return path in the same plane as the field-producing arcs. The coil structure consists of stacked planar units which give a desired field-gradient configuration. The size of the linear-field region is optimized by varying the current in each plane, by varying the location of a plane relative to the others in the stack, or by varying both current and location. Coils with linear regions having a wide range of length-to-diameter ratios can be designed, as illustrated by two examples. The construction of a prototype coil is presented and its performance in imaging confirms the analysis. This type of design is suited to magnetic resonance of the human head without obstruction from the shoulders.

Same-day surgery: the nurse's role

Outpatient surgery is one of the fastest growing trends In health care today. Providing preoperative and postoperative care to a diverse patient population in a limited amount of time presents numerous challenges. The nursing staff is required to assess the patient and resources, plan for the scheduled surgery and postdischarge care, implement the plan, and evaluate the patient's and family's understanding of the information and their ability to provide for self-care at home in as little as 2 hours. Preoperative care is discussed in this article along with specific guidelines for postoperative recovery and discharge planning. Care of the orthopaedic patient is highlighted throughout the discussion.

Organ transplantation at the Hartford Transplant Center

Over 1,243 organ transplants have been performed at the Hartford Transplant Center over the past two decades. Survival in kidney, heart, liver, and pancreas patients is at or above the national average. Hartford was one of the first centers to use triple immunosuppression, which significantly improved survival in kidney transplantation. For recipients of kidneys from living related donors and cadaveric kidneys, two-year actuarial graft survival has been 98% and 83%, respectively, over the last five years. For heart and liver transplants, two-year survival has been 79% and 67%, respectively. Despite high success rates at most transplant centers, donor organs remain scarce. This problem needs to be addressed through increased cooperative efforts in the health-care community and the general public.

Pharmaceutical representatives and emergency medicine residents: a national survey

STUDY OBJECTIVES

To determine the extent and diversity of involvement of pharmaceutical representatives in emergency medicine residency programs and to assess chief residents' beliefs and attitudes concerning this activity.

DESIGN AND PARTICIPANTS

A multi-item survey with cover letter was mailed to the chief resident at each of the 87 Accreditation Council on Graduate Medical Education-approved emergency medicine residency programs in the United States at the time of study conception.

MEASUREMENTS AND MAIN RESULTS

Eighty-three percent (72 of 87) of the questionnaires were returned. Ninety-three percent (66 of 71) of responders reported the involvement of pharmaceutical representatives in their emergency medicine residency. The most frequent activities (90%, 63 of 70) were to distribute small gifts (pens, notepads) and to provide meals during department functions such as journal clubs (80%, 56 of 70). Only 32 of 70 responding chief residents (46%) were aware of any established guidelines in their institution or residency program concerning relationships with pharmaceutical representatives, and 14 respondents (20%) believed that accepting gifts from pharmaceutical companies could affect their own prescribing habits. A few stated that pharmaceutical representative-sponsored educational functions were inappropriate.

CONCLUSION

The interaction of pharmaceutical representatives with emergency medicine residents and residencies is widespread. More than 50% of the institutions supporting emergency medicine residency programs have no formal guidelines with regard to the interaction of their residents with pharmaceutical representatives or their guidelines are not known to the person most responsible for approval and arrangement of the pharmaceutical representative interaction--the emergency medicine chief resident. While most chief residents believed that accepting small gifts was reasonable, they also believed that accepting gifts valued at $100 or more and pharmaceutical representative sponsorship of trips was inappropriate.

Alveolar-arterial oxygen gradients in elderly patients with suspected pulmonary embolism

STUDY OBJECTIVE

To determine the usefulness of the alveolar-arterial oxygen gradient for detecting pulmonary embolism in elderly patients presenting to the emergency department.

DESIGN

Retrospective cohort analysis.

SETTING

Two university-affiliated community hospitals.

TYPE OF PARTICIPANTS

Consecutive patients more than 64 years old who underwent pulmonary angiography for the presumed diagnosis of acute pulmonary embolism.

INTERVENTIONS

Arterial blood gas samples were chosen for comparative analysis only if obtained when the pulmonary embolism first was suspected clinically (before lung scans or angiograms) and the patient was breathing room air. Predicted PaO2 and alveolar-arterial gradients were calculated for each patient.

MEASUREMENT AND RESULTS

A total of 123 patients met all study criteria; mean +/- SD patient age was 74 +/- 6 years. Fifty-four patients (44%) had angiographically documented emboli. In this cohort, the mean PaO2 was 61.4 mm Hg (range, 34.3 to 83.8 mm Hg), and the mean alveolar-arterial gradient was 46.6 mm Hg (range, 19 to 75 mm Hg). In three patients, the alveolar-arterial gradient was normal for their age. However, in comparison with the 69 patients with normal pulmonary angiograms, there was no significant difference in PaO2 (mean, 59.9 mm Hg) or the alveolar-arterial gradient (mean, 46.0 mm Hg).

CONCLUSION

An elevated alveolar-arterial oxygen gradient is entirely nonspecific in the elderly population and is of minimal use in the diagnosis of acute pulmonary embolism. A normal alveolar-arterial gradient should not preclude further diagnostic procedures if there is a high index of suspicion.

Pre-operative combined 5-FU, low dose leucovorin, and sequential radiation therapy for unresectable rectal cancer

PURPOSE

We performed a Phase I trial to determine the maximum tolerated dose of combined pre-operative radiation (5040 cGy) and 2 cycles (bolus daily x 5) of 5-FU and low dose LV (20 mg/m2), followed by surgery and 10 cycles of post-operative LV/5-FU in patients with unresectable primary or recurrent rectal cancer.

METHODS AND MATERIALS

Twelve patients were entered. The initial dose of 5-FU was 325 mg/m2. 5-FU was to be escalated while the LV remained constant at 20 mg/m2. Chemotherapy began on day 1 and radiation on day 8. The post-operative chemotherapy, was not dose escalated; 5-FU: 425 mg/m2 and LV: 20 mg/m2. The median follow-up was 14 months (7-16 months).

RESULTS

Following pre-operative therapy, the resectability rate with negative margins was 91% and the pathologic complete response rate was 9%. For the combined modality segment (preoperative) the incidence of any grade 3+ toxicity was diarrhea: 17%, dysuria: 8%, mucositis: 8%, and erythema: 8%. The median nadir counts were WBC: 3.1, HGB: 8.8, and PLT: 153,000. The maximum tolerated dose of 5-FU for pre-operative combined LV/5-FU/RT was 325 mg/m2 with no escalation possible. Therefore, the recommended dose was less than 325 mg/m2.

CONCLUSIONS

Since adequate doses of 5-FU to treat systemic disease could not be delivered until at least 3 months (cycle 3) following the start of therapy, we do not recommend that this 5-FU, low dose LV, and sequential radiation therapy regimen be used as presently designed. However, given the 91% resectability rate we remain encouraged with this approach.

What do nursing students learn about pressure ulcers? A survey of content on pressure ulcers in nursing school textbooks

It is assumed that during their basic preparation, nurses are provided with the knowledge and skills to predict and prevent pressure ulcers. A review of five fundamentals of nursing and five medical-surgical nursing textbooks revealed that a nursing student may be exposed to as few as 200 lines of text and 10 tables, charts, or illustrations related to pressure ulcers during a program of studies. The information contained in the textbooks tended to be dispersed over three to seven chapters, incomplete, and sometimes inaccurate.

Tension pneumocephalus related to an epidermoid tumor of ethmoid sinus origin

A 37-year-old man presented with a four-week history of progressive left-sided weakness, frontal headache, confusion, and drowsiness. A computed tomography evaluation of the head revealed a 7-cm pneumatocele in the right frontoparietal region with shift of the falx to the left. The patient was taken to surgery, where the pneumatocele was decompressed and an epidermoid tumor that originated in the left ethmoid sinus was removed. After the operation, the presenting symptoms resolved promptly.

A phase III comparison trial of streptozotocin, mitomycin, and 5-fluorouracil with cisplatin, cytosine arabinoside, and caffeine in patients with advanced pancreatic carcinoma

Conventional chemotherapy for unresectable or metastatic adenocarcinoma of the pancreas has had little effect on palliation or survival. Almost all studies of systemic therapy have involved empiric use of a variety of Phase II or conventional agents alone or in combination. On the basis of recent studies using a human tumor pancreatic cancer (PC) xenograft in nude mice, a Phase I clinical trial of cisplatin, high-dose cytosine arabinoside (Ara-C), and caffeine (CAC) was performed in patients with advanced incurable PC. A tolerable dose and schedule of the three agents were developed. Seven of 18 patients with measurable disease in this Phase I trial had partial responses to CAC. A Phase III comparison of CAC versus standard treatment using streptozotocin, mitomycin, and 5-fluorouracil (SMF) was performed. Eighty-two patients with advanced PC were entered into this random assignment trial. The two treatment arms were well balanced for the usual prognostic factors. Although the acute (e.g., nausea and vomiting) toxicities of CAC were greater than those of SMF, both groups of patients tolerated treatment resonably well. Ninety percent of patients were evaluable for response. Two patients (5.5%) on the CAC treatment arm (95% confidence interval [CI], 0% to 15%) and four patients (10.2%) on the SMF treatment arm (95% CI, 1% to 22%) had objective responses (partial response in measurable disease or improvement in evaluable disease). No complete remissions were observed. The 95% confidence limits of response for CAC and SMF overlapped. The median duration of survival for all patients on the SMF treatment arm was 10 months, although it was 5 months on the CAC treatment arm (P = 0.008). In this Phase III comparison, CAC was not superior to conventional therapy with SMF in terms of response and was inferior for survival. Neither regimen is effective treatment for advanced PC.

Tumorigenicity of adenovirus-transformed cells and their sensitivity to tumor necrosis factor alpha and NK/LAK cell cytolysis

Sensitivity of a library of cloned adenovirus-transformed rat cell lines of varying tumorigenicity to cytotoxic action of tumor necrosis factor alpha (TNF alpha) was studied and correlated with their sensitivity to NK/LAK cell cytolysis. Our data confirm earlier reports that expression of the E1A oncogene of Ad2 or Ad5 is associated with sensitivity of transformed cells to TNF alpha and also NK/LAK cytotoxicity. Ad2-transformed cell line which expresses the E3 early region in addition to the E1 gene block is resistant to TNF alpha, but remains sensitive to NK/LAK cells. All cell lines which express the E1A oncogene of highly oncogenic Ad12 are resistant to NK but not LAK cells. Their sensitivity to TNF alpha, however, varies over a broad range and does not correlate with either their susceptibility to NK/LAK cytolysis or their tumorigenic potential.

In vivo and in vitro collagenolytic activity of Acanthamoeba castellanii

Axenic cultures of Acanthamoeba castellanii contained a collagenolytic enzyme that digested collagen shields and purified collagen in vitro. Specificity of biologic activity was determined by the addition of selected enzyme inhibitors to the assays and revealed that the parasite-conditioned medium contained both collagenase and lower concentrations of other proteolytic enzymes. However, most of the collagenolytic and pathogenic activity was directly attributable to specific collagenase. Intrastromal injection of sterile, Acanthamoeba-conditioned culture medium into naive Lewis rats produced corneal lesions clinically similar to and closely resembling those found in biopsy specimens of human patients diagnosed with acanthamoebic keratitis. Histopathologic analysis revealed moderate-to-severe neutrophil infiltration, disruption of stromal lamellae, and edema. Identical pathologic sequelae were produced by intrastromal injection of purified collagenase (25 units/ml). The pathogenicity of the soluble parasite-derived product was removed by passage over affinity columns armed with antibody specific for collagenase. These results indicated that soluble parasite-derived factors were capable of producing lesions characteristic of acanthamoebic keratitis and that the pathogenicity of these factors was either directly or indirectly attributable to specific collagenase activity.