COVID-19 vaccination induces distinct T-cell responses in pediatric solid organ transplant recipients and immunocompetent children

Immune responses to COVID-19 vaccination are attenuated in adult solid organ transplant recipients (SOTRs) and additional vaccine doses are recommended for this population. However, whether COVID-19 mRNA vaccine responses are limited in pediatric SOTRs (pSOTRs) compared to immunocompetent children is unknown. Due to SARS-CoV-2 evolution and mutations that evade neutralizing antibodies, T cells may provide important defense in SOTRs who mount poor humoral responses. Therefore, we assessed anti-SARS-CoV-2 IgG titers, surrogate neutralization, and spike (S)-specific T-cell responses to COVID-19 mRNA vaccines in pSOTRs and their healthy siblings (pHCs) before and after the bivalent vaccine dose. Despite immunosuppression, pSOTRs demonstrated humoral responses to both ancestral strain and Omicron subvariants following the primary ancestral strain monovalent mRNA COVID-19 series and multiple booster doses. These responses were not significantly different from those observed in pHCs and significantly higher six months after vaccination than responses in adult SOTRs two weeks post-vaccination. However, pSOTRs mounted limited S-specific CD8+ T-cell responses and qualitatively distinct CD4+ T-cell responses, primarily producing IL-2 and TNF with less IFN-γ production compared to pHCs. Bivalent vaccination enhanced humoral responses in some pSOTRs but did not shift the CD4+ T-cell responses toward increased IFN-γ production. Our findings indicate that S-specific CD4+ T cells in pSOTRs have distinct qualities with unknown protective capacity, yet vaccination produces cross-reactive antibodies not significantly different from responses in pHCs. Given altered T-cell responses, additional vaccine doses in pSOTRs to maintain high titer cross-reactive antibodies may be important in ensuring protection against SARS-CoV-2.

Emergency myelopoiesis distinguishes multisystem inflammatory syndrome in children from pediatric severe COVID-19

BACKGROUND

Multisystem inflammatory syndrome in children (MIS-C) is a hyperinflammatory condition caused by recent SARS-CoV-2 infection, but the underlying immunological mechanisms driving this distinct syndrome are unknown.

METHODS

We utilized high dimensional flow cytometry, cell-free (cf) DNA, and cytokine and chemokine profiling to identify mechanisms of critical illness distinguishing MIS-C from severe acute COVID-19 (SAC).

RESULTS

Compared to SAC, MIS-C patients demonstrated profound innate immune cell death and features of emergency myelopoiesis (EM), an understudied phenomenon observed in severe inflammation. EM signatures were characterized by fewer mature myeloid cells in the periphery and decreased expression of HLA-DR and CD86 on antigen presenting cells. IL-27, a cytokine known to drive hematopoietic stem cells towards EM, was increased in MIS-C, and correlated with immature cell signatures in MIS-C. Upon recovery, EM signatures decreased, and IL-27 plasma levels returned to normal levels. Despite profound lymphopenia, we report a lack of cfDNA released by adaptive immune cells and increased CCR7 expression on T cells indicative of egress out of peripheral blood.

CONCLUSIONS

Immune cell signatures of EM combined with elevated innate immune cell-derived cfDNA levels distinguish MIS-C from SAC in children and provide mechanistic insight into dysregulated immunity contributing towards MIS-C, offering potential diagnostic and therapeutic targets.

Heterologous versus homologous boosting regimens elicit qualitatively distinct, BA.5-cross reactive T cells in transplant recipients

BACKGROUND

The Omicron BA.5 subvariant of SARS-CoV-2 markedly escapes neutralizing antibodies induced by vaccination due to mutations in the Spike (S) protein. Solid organ transplant recipients (SOTRs) suffer high COVID-19 morbidity and demonstrate poor Omicron strain recognition after COVID-19 vaccination. T cell responses may provide a crucial second line of defense. Therefore, it is critical to understand which vaccine regimens induce robust, conserved T cell responses.

METHODS

We evaluated anti-S IgG titers, subvariant pseudo-neutralization, and S-specific CD4+ and CD8+ T cell responses from SOTRs in a national, prospective observational trial (n=75). Participants were selected if they received 3 doses of mRNA (homologous boosting) or two doses of mRNA followed by Ad26.COV2.S (heterologous boosting).

RESULTS

Homologous boosting with three mRNA doses induced the highest anti-S IgG titers. However, antibodies induced by both vaccine regimens demonstrated significantly lower pseudo-neutralization against BA.5 compared to the ancestral strain. In contrast, vaccine-induced S-specific T cells maintained cross-reactivity against BA.5 compared to ancestral recognition. Homologous boosting induced higher frequencies of activated polyfunctional CD4+ T cell responses, with polyfunctional IL-21+ peripheral T follicular helper cells increased in mRNA-1273 compared to BNT¬¬162b2. IL-21+ cells robustly correlated with antibody titers. Heterologous boosting with Ad26.COV2.S did not increase CD8+ responses compared to homologous boosting.

CONCLUSIONS

These data demonstrate that boosting with the ancestral strain can induce cross-reactive T cell responses against emerging variants of concern in SOTRs, but alterative vaccine strategies are required to induce robust CD8+ T cell responses.

TRIAL REGISTRATION

IRB00248540FUNDING. U01AI138897, U54CA260492, Emory COVID-19 research repository.

Coronary artery bypass grafting in patients with advanced left ventricular dysfunction

OBJECTIVE

The aim of this study was to determine the long-term survival and control of angina in patients with coronary artery disease and sequentially decreased ejection fractions (EF) after first-time coronary artery bypass grafting.

METHODS

Between 1981 and 1995, 156 (1.3%) patients with an EF less than 0.25 (group 1), 588 (5%) patients with an EF of 0.25 to 0.34 (group 2), 2,438 (20.6%) patients with an EF of 0.35 to 0.49 (group 3), and 8,648 (73.1%) patients with an EF equal to or greater than 0.50 (group 4) underwent coronary artery bypass grafting. The EFs were determined by uniplanar or biplanar left ventriculography. For each group, the clinical and angiographic characteristics and the operative and outcome data were compared. Survival curves were derived and compared for each group. Correlates of angina, and of early (30-day) and long-term mortality, for all groups were analyzed.

RESULTS

For all groups the mean age was approximately 60+/-10 years. Group 1 had the highest percentage of patients who were men (88%), had congestive heart failure (34%), had hypertension (53%), and had left main coronary artery disease (24%). Groups 1 through 3, compared with group 4, had a lower percentage of complete revascularization (p < 0.0001), a lower percentage of internal mammary artery grafts (p < 0.0001), and a greater use of intraaortic balloon pump (p < 0.0001), but had similar cross-clamp and cardiopulmonary bypass times, number of grafts, incidences of myocardial infarction, and stroke. Hospital mortality for groups 1, 2, 3, and 4 was 3.8% (n = 6), 3.4% (n = 20), 3% (n = 72), and 1.6% (n = 134), respectively. Groups 1 through 3, compared with group 4, had similar incidences of angina during follow-up (31% to 40% versus 33%, respectively; p < 0.06). Survival was greatest for group 4 compared with groups 1 through 3 at 1, 5, and 10 years (p < 0.0001). Patients in group 1 had 1-, 5-, and 7-year survivals of 90%, 64%, and 49%. Multivariate correlates of early mortality were advanced age, female sex, decreased EF, hypertension, diabetes, and emergency operation. Multivariate correlates of long-term mortality included severity of preoperative angina class, congestive heart failure, number of diseased vessels, and incomplete revascularization. The strongest correlates of angina at follow-up were younger age, female sex, previous myocardial infarction, lower ejection fraction, and incomplete revascularization. The absence of an internal mammary artery graft did not predict the occurrence of angina or influence long-term survival.

CONCLUSIONS

In the long term there is a higher mortality in patients with sequentially decreased left ventricular function undergoing coronary artery bypass grafting, although more than 60% of patients with an EF less than 0.25 were alive and had good control of angina at 5 years despite having a higher percentage of risk factors, poorer functional status, and more complex coronary disease. Failure of symptom control and survival beyond 5 years appeared to be influenced by preexisting medical conditions and factors that affect the ability to completely revascularize the myocardium. These results suggest that in selected patients with ischemia and poor left ventricular function, coronary artery bypass grafting may preserve remaining viable myocardium, provide relief of symptoms, and offer survival greater than 60% at more than 5 years.

Single-field total lymphoid irradiation in the treatment of refractory rejection after heart transplantation

Nine heart transplant recipients were treated with single-field total lymphoid irradiation (TLI) for early (<1 year) or late (>1 year) rejection that was refractory to multiple regimens of immunosuppressive therapy. For patients with early rejection (n = 6), the rejection frequency (rejections/patient/month) decreased from pre-TLI of 1.63 to post-TLI of .02 (p < .001), and for patients with late rejection (n = 3), the rejection frequency decreased from pre-TLI of .23 to post-TLI of .05 (p < .02). The reduced rejection frequencies have been maintained for a mean follow-up of 28.6 (8 to 78) months, and adverse events during or late after TLI were uncommon. Single-field TLI is a safe and effective technique in the management of refractory rejection early or late after heart transplantation.

Risk stratification after myocardial infarction

The optimal approach to risk stratification after myocardial infarction remains controversial. Early risk stratification is designed to identify those patients who may benefit from mechanical myocardial revascularization procedures or more intensive medical therapy to prevent early adverse outcomes. Use of exercise testing and noninvasive cardiac imaging to identify residual myocardial ischemia and left ventricular dysfunction in order to divide patients into high- and low-risk groups has gained increasing acceptance. Patients at high risk then undergo cardiac catheterization. There is also support for early cardiac catheterization to permit the rapid identification of patients who may benefit from mechanical revascularization. The challenge to physicians is to select the most accurate, safe, and cost-effective approach at their particular institution.

Report on a focus of onchocerciasis in Esmeraldas province of Ecuador

A case suggesting the occurrence of onchocerciasis in Ecuador was first reported in 1952. The appearance of another case in 1977 provided the stimulus to do an epidemiologic survey on an isolated 20-km section of the Cayapa River in Esmeraldas Province. The Mazzotti test, skin biopsy, and nodulectomy were performed on 300 inhabitants of the area. Of the 300 who were tested, 210 (70%) reacted positively to the Mazzotti test, only 20 of whom had a negative skin biopsy. An additional 10 patients with a negative Mazzotti test had a positive skin biopsy. Combining the results of the Mazzotti test and skin biopsy show a 73% prevalence of onchocerciasis. Sixty-four patients (21%) had nodules, and evidence suggests that ocular pathology may be present.

Clinical pharmacy in the family practice residency programs

A descriptive study of all family practice residencies in the United States was conducted to determine the level of teaching by clinical pharmacists. Ninety percent of the programs were covered, and 29 percent of them had teaching involvement by pharmacists. Two thirds of all pharmacists held an academic appointment. One half of the pharmacists had a Doctor of Pharmacy degree. Three fourths were under 36 years of age and the salary ranged from +15,000 to over +27,000. Duties of the pharmacists were extremely varied. In general, residency directors reported that adding clinical pharmacy to the teaching program was a positive asset.

Diagnosis and treatment of five parasites. Enterobius vermicularis, Giardia lamblia, Trichuris trichiura, Ascaris lumbricoides, Entamoeba histolytica

General descriptions and monographs of the five parasites most likely to be seen in U. S. patients are presented. The appended monographs are designed to be a starting reference for answering drug information questions regarding these parasites. The drugs covered in the monographs are listed in the order of suggested use.

Provision of medicines in Ecuador

Part of the drug budget in Ecuador goes on expensive, non-essential, or unsafe proprietary medicines, while many drugs considered necessary in developed countries are unavailable. The promotional activities of pharmaceutical companies are unchecked and objective drug information in scarce.