Ella J. Ariza-Heredia

Cytomegalovirus diseases after hematopoietic stem cell transplantation: A mini-review

Cytomegalovirus (CMV) infection remains a significant complication after hematopoietic stem cell transplantation (HSCT) and may have a deleterious impact on the overall outcome after transplantation. In addition to the direct effects of CMV infection, tissue-invasive CMV diseases may be associated with increased risk of graft versus host disease, myelosuppression, and invasive bacterial and fungal infections. Because of these direct and indirect adverse effects, prevention of CMV infection, mostly through pre-emptive therapy, is one of the essential strategies that may improve outcomes of HSCT recipients. Management of CMV infection relies mainly on intravenous (IV) antiviral therapy with ganciclovir and foscarnet, with or without IV polyclonal immunoglobulins. Although viral resistance remains rare, better tolerated antiviral agents with less serious side effects are needed, and a few will be evaluated in phase III clinical trials in the near future.

Faculty and Resident Physicians' Attitudes, Perceptions, and Knowledge about Antimicrobial Use and Resistance

We surveyed faculty and residents to assess attitudes, perceptions, and knowledge about antimicrobial use and resistance. Most respondents were concerned about resistance when prescribing antibiotics and agreed that antibiotics are overused, that inappropriate use is professionally unethical, and that others, but not themselves, overprescribe antibiotics. Antimicrobial stewardship programs should capitalize on these perceptions.

Immunodeficiency scoring index to predict poor outcomes in hematopoietic cell transplant recipients with RSV infections

We developed an immunodeficiency scoring index for respiratory syncytial virus (ISI-RSV) infection, based on a cohort of 237 allogeneic hematopoietic cell transplant (allo-HCT) recipients, that can predict the risk of progression to lower respiratory tract infection (LRTI) and RSV-associated mortality. A weighted index was calculated using adjusted hazard ratios for immunodeficiency markers. Based on the ISI-RSV (range, 0-12), patients were stratified into low (0-2), moderate (3-6), and high (7-12) risk groups. A significant trend of increasing incidence of LRTI and RSV-associated mortality was observed as the risk increased from low to moderate to high (P < .001). Patients in the high-risk group had the greatest benefit of ribavirin-based therapy at the upper respiratory tract infection stage and the highest risk for progression to LRTI and death when antiviral therapy was not given (6.5 [95% confidence interval (CI), 1.8-23.6] and 8.1 [95% CI, 1.1-57.6], respectively). The ISI-RSV is designed to stratify allo-HCT recipients with RSV infection into groups according to their risk for progression to LRTI and RSV-associated mortality. Identification of high-risk groups using this index would distinguish patients who would benefit the most from antiviral therapy, mainly with aerosolized ribavirin. The ISI-RSV should be validated in a multi-institutional study.

Human herpes virus 8 in solid organ transplantation.

Human herpes virus 8 (HHV-8) is a geographically limited virus that causes neoplastic and nonneoplastic diseases predominantly in endemic regions. Primary HHV-8 infection, which is usually asymptomatic in immunocompetent individuals, result in lifelong latency. When the equilibrium between virus and host immunity is disturbed, such as after organ transplantation, HHV-8 may activate molecular pathways that drive oncogenesis. Kaposis sarcoma, primary effusion lymphoma, and Castlemans disease are the major malignancies associated with HHV-8. The incidences of these neoplastic pathologies mirror the geographic HHV-8 seroprevalence, and certain groups of patients are at higher risk. In this context, the risk of HHV-8 and its clinical disease is highest in immunocompromised patients, including transplant recipients. Solid organ transplant recipients from HHV-8 endemic regions may develop HHV-8 reactivation or primary infection and manifest with Kaposis sarcoma or less commonly primary effusion lymphoma and Castlemans disease; these neoplastic diseases are reported much less commonly in low-prevalent areas. There is currently no standard method of screening for HHV-8 infection in the transplant setting, although HHV-8 polymerase chain reaction is available to confirm clinical suspicion of infection. Management of HHV-8-associated diseases entails primarily a reduction in the degree of pharmacologic immunosuppression and, in some cases, chemotherapy may be required. The mammalian target of rapamycin inhibitor sirolimus may have the potential for management because of its antiproliferative properties. The role of antiviral drugs for HHV-8 prevention and treatment is yet to be defined.

Impact of urinary tract infection on allograft function after kidney transplantation

Urinary tract infection (UTI) is the most common infectious complication after kidney transplantation. We aim to determine its impact on allograft function as indicated by several measures such as iothalamate glomerular filtration rate (iGFR), estimated glomerular filtration rate (eGFR), and creatinine value.

Pulmonary imaging of pandemic influenza H1N1 infection: relationship between clinical presentation and disease burden on chest radiography and CT

The potential for pulmonary involvement among patients presenting with novel swine-origin influenza A (H1N1) is high. To investigate the utility of chest imaging in this setting, we correlated clinical presentation with chest radiographic and CT findings in patients with proven H1N1 cases. Subjects included all patients presenting with laboratory-confirmed H1N1 between 1 May and 10 September 2009 to one of three urban hospitals. Clinical information was gathered retrospectively, including symptoms, possible risk factors, treatment and hospital survival. Imaging studies were re-read for study purposes, and CXR findings compared with CT scans when available. During the study period, 157 patients presented with subsequently proven H1N1 infection. Hospital admission was necessary for 94 (60%) patients, 16 (10%) were admitted to intensive care and 6 (4%) died. An initial CXR, carried out for 123 (78%) patients, was abnormal in only 40 (33%) cases. Factors associated with increased likelihood for radiographic lung abnormalities were dyspnoea (p<0.001), hypoxaemia (p<0.001) and diabetes mellitus (p = 0.023). Chest CT was performed in 21 patients, and 19 (90%) showed consolidation, ground-glass opacity, nodules or a combination of these findings. 4 of 21 patients had negative CXR and positive CT. Compared with CT, plain CXR was less sensitive in detecting H1N1 pulmonary disease among immunocompromised hosts than in other patients (p = 0.0072). A normal CXR is common among patients presenting to the hospital for H1N1-related symptoms without evidence of respiratory difficulties. The CXR may significantly underestimate lung involvement in the setting of immunosuppression.

Urinary tract infections in kidney transplant recipients: role of gender, urologic abnormalities, and antimicrobial prophylaxis.

BACKGROUND Urinary tract infections (UTI), the most common infectious complications after kidney transplantation, are associated with poor allograft survival. Identifying its predisposing factors is therefore remarkably important in order to optimize prevention strategies. MATERIAL AND METHODS A retrospective study was performed in a cohort of patients who received kidney transplantation between June 2007 and June 2009. Factors associated with development of UTI were assessed. RESULTS The population consisted of 301 patients, with majority receiving allograft from living donors (85%). A total of 101 patients (34%) developed at least one episode of UTI, and 25% of the episodes occurred during the first year after transplantation. Risk factors associated with increased risk of UTI were female gender, recurrent UTI prior to transplant, and presence of urological abnormalities. Trimethoprim-sulfamethoxazole (TMP-SMZ) use was associated with a lower risk of UTI, including a lower risk of recurrent UTI. CONCLUSIONS In this cohort of predominantly living donor kidney transplant recipients, we report a high incidence of UTI, despite our practice of early ureteral and Foley catheter removal. Female gender and prior recurrent UTI or urological abnormalities were predisposing factors, while TMP-SMZ use had a protective role. These clinical relevant findings should guide clinicians in optimizing prevention strategies against UTI in kidney transplant recipients.

Fecal colonization and infection with Pseudomonas aeruginosa in recipients of allogeneic hematopoietic stem cell transplantation.

Pseudomonas aeruginosa, especially multidrug‐resistant (MDR) isolates, is an important pathogen in allogeneic hematopoietic stem cell transplant (HCT) recipients. The ability to identify patients at risk for these infections and administer appropriate empiric therapy, particularly during episodes of neutropenia, may improve outcomes and also direct infection control and antimicrobial stewardship efforts. Many transplant centers obtain routine surveillance stool cultures (SSCs) from HCT recipients to test for colonization with vancomycin‐resistant enterococci, and extended‐spectrum beta lactamase‐producing Enterobacteriaceae. Our center initiated the performance of SSCs for P. aeruginosa, because of a perceived increase in the frequency of infection with MDR strains. The aim of this study was to determine the utility of this practice.

Clinical and radiological features of respiratory syncytial virus in solid organ transplant recipients: a single‐center experience

Respiratory syncytial virus (RSV) infections range from upper respiratory illness to severe lower respiratory disease. There is no universally accepted treatment for RSV in solid organ transplant (SOT) recipients.

Vaccination guidelines after hematopoietic stem cell transplantation: practitioners' knowledge, attitudes, and gap between guidelines and clinical practice

Hematopoietic stem cell transplant (HCT) recipients are more susceptible to infections from vaccine‐preventable diseases than the general population. Despite the development of international consensus guidelines addressing immunization after HCT, studies have shown that deviations from recommended immunization practices commonly occur.