Evaluation of pulmonary abnormalities in recipients of hematopoietic cell transplants and cellular therapies.

Hematopoietic cell transplant (HCT) and chimeric antigen receptor T-cell (CAR-T) therapy recipients are susceptible to multiple pulmonary complications that are caused by infectious and noninfectious processes. Numerous variables can be associated with specific pulmonary diseases including time from transplantation, presence of graft versus host disease (GVHD), underlying disease, and prolonged neutropenia and lymphocytopenia. Most pulmonary complications are infectious in origin, with bacterial pneumonia remaining the most common pulmonary infection, particularly before neutrophil engraftment. Invasive fungal infections continue to affect this patient population even when antifungal prophylaxis is used. Noninfectious pulmonary complications include a wide differential of pathologies in this population, and as clinical presentations of these various pulmonary disorders often overlap, clinicians frequently will use a multidisciplinary approach in diagnosing these abnormalities. Radiography, particularly with chest computed tomography (CT) imaging, is an essential tool in identifying pulmonary pathology and potential sources. While standard microbiological cultures of respiratory specimens are still utilized, their role is limited by low sensitivity and diagnostic yield. The likelihood of obtaining a diagnosis can be improved by using other microbiological assays, including fungal antigen tests and molecular diagnostic methods, particularly if specimens are collected via bronchoscopy. This review will highlight the more common causes of pulmonary diseases encountered after HCT and CAR-T and will examine the different methods in their diagnosis.

Monoclonal antibody treatment for COVID-19 in solid organ transplant recipients.

Solid organ transplant (SOT) recipients are at high risk for severe coronavirus disease 2019 (COVID-19). Studies suggest that early intervention with monoclonal antibody (MAB) treatment directed against the SARS-CoV-2 spike protein may reduce the risk of emergency department visits or hospitalization for COVID-19, especially in high-risk patients. Herein, we describe our single-center experience of 93 SOT (50 kidney, 17 liver, 11 lung, nine heart, and six dual-organ) recipients with mild to moderate COVID-19 who were treated with bamlanivimab or casirivimab-imdevimab per emergency use authorization guidelines. Median age of recipients was 55 [(Interquartile range) 44-63] years, and 41% were diabetic. Median time from transplant to MAB was 64 (IQR 24-122) months and median time from the onset of COVID-19 symptoms to the infusion was 6 (IQR 4-7) days. All patients had a minimum 30 days of study follow-up. The 30-day hospitalization rate for COVID-19-directed therapy was 8.7%. Infusion-related adverse events were rare and generally mild. Biopsy-proven organ rejection occurred in two patients, and there were no graft losses or deaths. A comparator group of 72 SOT recipients diagnosed with COVID-19 who were eligible but did not receive MAB treatment had a higher 30-day hospitalization rate for COVID-19-directed therapy (15.3%), although this difference was not statistically significant, after adjustment for age (Odds Ratio 0.49 [95% Confidence Interval 0.18-1.32], p = 0.16). Our experience suggests that MAB treatment, with respect to the available MAB formulations and circulating viral variants present during our study period, may provide favorable outcomes for mild to moderate COVID-19 in SOT recipients.

Humoral and cellular immune responses to the SARS-CoV-2 BNT162b2 vaccine among a cohort of solid organ transplant recipients and healthy controls.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is associated with increased morbidity and mortality in solid organ transplant (SOT) recipients. Despite exclusion from SARS-CoV-2 vaccine clinical trials, these individuals were identified as high-risk and prioritized for vaccination in public health guidelines. METHODS: We prospectively evaluated humoral and cellular immune responses to two doses of the SARS-CoV-2 mRNA vaccine, BNT162b2, in 56 SOT recipients and 26 healthy controls (HCs). Blood specimens collected from participants prior to each dose and following the second dose were tested for SARS-CoV-2-specific antibodies, as well as CD4+ and CD8+ T-cell responses. RESULTS: SOT recipients demonstrated lower mean anti-SARS-CoV-2 antibody levels compared to HCs after each dose, and only 21.6% achieved an antibody response after the second dose within the range of HC responses. Similarly, the percentage of responsive CD4+ and CD8+ T cells in SOT recipients was lower than in HCs. While most HCs showed notable humoral and cellular responses, responses were less concordant in SOT recipients, with some showing evidence of either humoral or cellular response, but not both. CONCLUSION: Humoral and cellular immune responses to the BNT162b2 vaccine are markedly reduced in SOT recipients as compared to HCs, suggesting that SOT recipients may benefit from more tailored regimens such as higher dose and/or additional vaccinations.

Alternative strategies of posttransplant influenza vaccination in adult solid organ transplant recipients.

Solid organ transplant (SOT) recipients are at increased risk of influenza disease and associated complications. The mainstay of prevention is the annual standard-dose influenza vaccine, as studies showed decreased influenza-related morbidity and mortality in vaccinated SOT recipients compared to those unvaccinated. Nonetheless, the immune response in this high-risk population is suboptimal compared to healthy individuals. Over the past two decades, several vaccination strategies have been investigated to overcome this inadequate immune response in SOT recipients. Howbeit, the best vaccination strategy and optimal timing of influenza vaccination remain unclear. This review will provide a detailed summary of studies of various influenza vaccination strategies in adult SOT recipients, discussing immunogenicity results, and addressing their limitations and knowledge gaps.

SARS-CoV-2 vaccine safety and immunogenicity in patients with hematologic malignancies, transplantation, and cellular therapies.

Individuals with hematological malignancies and hematopoietic stem cell transplant (HCT) recipients are immunologically heterogenous groups with varying degrees of immunosuppression at increased risk of severe disease and mortality from SARS-CoV-2 infection. SARS-CoV-2 vaccines are key interventions to preventing severe COVID-19 and its complications. While these individuals were excluded from initial vaccine trials, there is now a growing body of acceptable safety and immunogenicity data among these individuals. A consistent signal for new or worsening graft versus host disease in allogeneic HCT recipients has not been demonstrated post-vaccination. Immunogenicity in these populations is variable depending on disease and treatment factors. However, serological responses may not accurately reflect vaccine protection as correlates of protection within these populations are not yet established. Large-scale studies powered to identify rare serious events, resolve differences in vaccine responses between different vaccination strategies, and identify immune correlates of protection within these populations are needed.

Hepatic transplant during SARS-CoV-2 (COVID-19) pandemic. A literature review.

ANTECEDENTES: En diciembre de 2019 se identificó en la ciudad de Wuhan, China, un nuevo beta coronavirus, el SARS-CoV-2, como agente causal de neumonía grave, conocida como COVID-19, lo cual ha provocado medidas estrictas de aislamiento, cierre de programas de trasplante hepático y la necesidad de modificar los protocolos de tratamiento. OBJETIVO: Documentar la información publicada sobre el impacto de la COVID-19 en la población con antecedente de trasplante hepático y establecer un protocolo de tratamiento. MÉTODO: Se buscaron en PubMed los términos MeSH "SARS-CoV-2", "COVID-19", "trasplante hepático" y "tratamiento". RESULTADOS: Hasta el momento se ha demostrado en la población con trasplante hepático una mayor facilidad para adquirir el virus, sin una diferencia en la mortalidad al compararla con la población general. La inmunosupresión debe continuar, sin suspender los inhibidores de la calcineurina. Del tratamiento específico, los esteroides son los que han demostrado el mayor beneficio clínico y una disminución de la mortalidad. CONCLUSIÓN: El trasplante hepático no se asocia de manera independiente a una mayor mortalidad. Otros factores, además del trasplante, deben tomarse en cuenta al momento de establecer la gravedad. BACKGROUND: In December 2019, a new beta coronavirus, SARS-CoV-2, was identified in the city of Wuhan, China, as a causative agent of severe pneumonia, known as COVID-19, which has led to strict isolation measures, closure of liver transplantation programs and the need to modify treatment protocols. OBJECTIVE: Document the information published so far on the impact of COVID-19 in the population with a history of liver transplantation and establish a treatment protocol. METHOD: MeSH terms were searched for "SARS-CoV-2", "COVID-19", "liver transplantation" and "treatment". RESULTS: Up to now, a greater ease in acquiring the virus has been shown in the liver transplant population, without a difference in mortality when compared to the general population. Immunosuppression should continue at the minimum tolerated levels, without suspending calcineurin inhibitors. Of the specific treatment, steroids are those that have shown the greatest clinical benefit and decreased mortality. CONCLUSION: Liver transplantation is not independently associated with higher mortality. Factors other than transplantation must be taken into account when considering the risk of severity.

Long-term outcomes of cytomegalovirus infection and disease after lung or heart-lung transplantation with a delayed ganciclovir regimen.

BACKGROUND: Information is limited on long-term outcomes after preemptive use of ganciclovir to control cytomegalovirus (CMV) infection in lung transplantation. METHODS: We studied 78 lung recipients who received antithymocyte globulin induction from 1994 to 2000. All patients received six months of oral acyclovir (800 mg TID). This was interrupted three wk post transplantation for a two-wk course of IV ganciclovir. Additional courses of ganciclovir were administered based on serial virological monitoring. CMV-mismatched patients (R-D+) also received four doses of CMV immunoglobulin between weeks 2 and 8. RESULTS: The one yr cumulative risk of CMV disease was 2% (1/61) in CMV seropositive (R+) patients, but was 37% (6/17) in R-D+ patients (p < 0.0001). Over 4.3 yr of follow-up, patients with CMV infection developed more chronic graft dysfunction caused by bronchiolitis obliterans or bronchiolitis obliterans syndrome than patients without CMV infection (p = 0.012). This effect was also apparent in the subgroup of R+ recipients (p = 0.043). Acute rejection and overall survival were not associated with CMV infection. CONCLUSIONS: The use of prophylactic acyclovir and short preemptive courses of ganciclovir effectively controlled CMV disease in R+ patients, but was a relative failure in R-D+ patients. CMV infection was significantly associated with chronic graft dysfunction, even in R+ recipients who had good control of CMV symptoms.

Histoplasmosis in Patients With Cell-Mediated Immunodeficiency: Human Immunodeficiency Virus Infection, Organ Transplantation, and Tumor Necrosis Factor-α Inhibition.

Background. Histoplasmosis causes severe disease in patients with defects of cell-mediated immunity. It is not known whether outcomes vary related to the type of immunodeficiency or class of antifungal treatment. Methods. We reviewed cases of active histoplasmosis that occurred at Vanderbilt University Medical Center from July 1999 to June 2012 in patients with human immunodeficiency virus (HIV) infection, a history of transplantation, or tumor necrosis factor (TNF)-α inhibitor use. These groups were compared for differences in clinical presentation and outcomes. In addition, outcomes were related to the initial choice of treatment. Results. Ninety cases were identified (56 HIV, 23 transplant, 11 TNF-α inhibitor). Tumor necrosis factor-α patients had milder disease, shorter courses of therapy, and fewer relapses than HIV patients. Histoplasma antigenuria was highly prevalent in all groups (HIV 88%, transplant 95%, TNF-α 91%). Organ transplant recipients received amphotericin B formulation as initial therapy less often than other groups (22% vs 57% HIV vs 55% TNF-α; P = .006). Treatment failures only occurred in patients with severe disease. The failure rate was similar whether patients received initial amphotericin or triazole therapy. Ninety-day histoplasmosis-related mortality was 9% for all groups and did not vary significantly with choice of initial treatment. Conclusions. Histoplasmosis caused milder disease in patients receiving TNF-α inhibitors than patients with HIV or solid organ transplantation. Treatment failures and mortality only occurred in patients with severe disease and did not vary based on type of immunosuppression or choice of initial therapy.

Tularemia pneumonia.

Francisella tularensis is a zoonotic infection that can be acquired in multiple ways, including a bite from an arthropod, the handling of animal carcasses, consumption of contaminated food and water, or inhalation of infected particles. The most virulent subspecies of F tularensis is type A, which is almost exclusively seen in North America. Pneumonia can occur in tularemia, as either a primary process from direct inhalation, or as a secondary manifestation of ulceroglandular or typhoidal disease. This article describes the history of this infection, epidemiology, methods of diagnosis and treatment, and its potential as a bioterrorism weapon.

Polyomavirus infection and its impact on renal function and long-term outcomes after lung transplantation.

BACKGROUND: Polyomavirus infection causes nephropathy after kidney transplantation but has not been thoroughly investigated in nonrenal organ transplantation. METHODS: Ninety lung transplant recipients were enrolled, and they provided urine samples for over 4.5 years. Samples were analyzed for BK virus (BKV), JC virus (JCV), and simian virus 40 (SV40) by conventional and quantitative real-time polymerase chain reaction. RESULTS: Fifty-nine (66%) patients had polyomavirus detected at least once, including 38 patients (42%) for BKV, 25 patients (28%) for JCV, and six patients (7%) for SV40. Frequency of virus shedding in serial urine samples by patients positive at least once varied significantly among viruses: JCV, 64%; BKV, 48%; and SV40, 14%. Urinary viral loads for BKV (10 copies/mL) and JCV (10 copies/mL) were higher than for SV40 (10 copies/mL; P=0.001 and 0.0003, respectively). Polyomavirus infection was associated with a pretransplant diagnosis of chronic obstructive pulmonary disease (odds ratio 6.0; P=0.016) but was less common in patients with a history of acute rejection (odds ratio 0.28; P=0.016). SV40 infection was associated with sirolimus-based immunosuppression (P=0.037). Reduced survival was noted for patients with BKV infection (P=0.03). Patients with polyomavirus infection did not have worse renal function than those without infection, but in patients with BKV infection, creatinine clearances were lower at times when viral shedding was detected (P=0.038). CONCLUSIONS: BKV and JCV were commonly detected in the urine of lung transplant recipients; SV40 was found at low frequency. No definite impact of polyomavirus infection on renal function was documented. BKV infection was associated with poorer survival.

A prospective longitudinal study of polyomavirus shedding in lung-transplant recipients.

BACKGROUND: Polyomavirus infection causes renal dysfunction after kidney transplantation, but it has not been thoroughly investigated in nonrenal solid-organ transplantation. METHODS: Fifty lung-transplant recipients provided prospective urine and blood samples over the course of 17 months. Samples were analyzed for BK virus (BKV), JC virus (JCV), and simian virus 40 (SV40) using conventional polymerase chain reaction (PCR), sequence analysis, and quantitative real-time PCR. RESULTS: Thirty-one (62%) of 50 patients had polyomavirus detected in at least 1 urine specimen, including 16 (32%) for BKV, 12 (24%) for JCV, and 6 (12%) for SV40. Mean BKV loads (5.0 log(10) copies/mL) did not differ from those of JCV (5.7 log(10) copies/mL; P=.38), but SV40 loads (2.5 log(10) copies/mL) were lower than those of BKV (P=.006) and JCV (P=.002). Blood samples were negative. Infection with individual polyomaviruses or polyomavirus infection in aggregate was not associated with reduced creatinine clearance. Patients not shedding polyomavirus had better survival than patients shedding polyomavirus (P=.049). CONCLUSIONS: Polyomaviruses BKV and JCV were commonly detected in urine from lung-transplant recipients. SV40 was found in 12% of patients but was shed at a lower frequency and with lower viral loads than the other viruses. Polyomavirus infection was not associated with renal dysfunction.