Risk Factors for the Development of Cytomegalovirus Resistance in Solid Organ Transplantation: A Retrospective Case-Control Study

BACKGROUND

Cytomegalovirus (CMV) resistance is an emerging problem in solid organ transplant recipients. Risk factors are not well defined.

METHODS

Recipients with CMV viremia of solid organ transplants who underwent CMV resistance testing between January 2010 and March 2016 were divided in 2 groups: proven CMV resistance and refractory CMV infection. A third group was added to compare patients with viremia during the study period with patients with no resistance proven or suspected. We aimed to identify risk factors associated with the occurrence of CMV genotypic resistance.

RESULTS

Forty-nine patients underwent resistance testing. Eleven (22.45%) developed genotypic mutations. Group 1 vs groups 2 and 3 had higher prednisone (P = .01) and tacrolimus levels (P = .03); did not respond to antivirals (P < .0001); and had a higher rate of fungal infections (P = .03). CMV resistance was less common in liver and kidney vs heart, small bowel, and mutivisceral recipients (P = .0007). There was no difference in duration of antiviral prophylaxis, viremia while on antiviral prophylaxis, rate of end-organ disease, graft loss, and overall survival. Persistent clinical disease and viremia despite antiviral therapy was the most important risk factor for development of CMV resistance.

CONCLUSION

Persistent clinical disease despite antiviral therapy is an important risk factor and may in part be due to a high degree of immunosuppression. Graft loss and survival were not impacted by CMV resistance.

Adenovirus-A Deadly Disease in the Solid Organ Transplant Population: Risk Factors and Outcomes

BACKGROUND

The importance of adenoviruses (AdV) in the immunocompromised population has been more recognized in recent decades. We aimed to assess the risk factors and outcomes associated with AdV in solid organ transplant recipients.

METHODS

This was a retrospective cohort study of solid organ transplant recipients who tested positive for AdV between January 1, 2004, and March 12, 2014. The subjects were divided in 2 groups: AdV asymptomatic infection and AdV disease. The characteristics and outcomes of the groups were compared using Wilcoxon rank-sum and Fisher exact tests; logistic regression was performed to evaluate risk factors.

RESULTS

A total of 125 patients were included with a mean (SD) age of 9.79 years (16.54); 49.6% were male, and 20.8% had AdV disease. No significant risk factors were found for AdV disease by univariate analyses. Comparing patients with disease and with asymptomatic infection, rejections during the first year after testing positive for AdV were 7 (26.92%) vs 17 (17.17%); mortality at 1 year post-transplantation was 26.92% vs 6.06% (P = .006), respectively, and at 1 year after testing positive for AdV was 38.46% vs 11.11% (P = .002), respectively.

CONCLUSION

No independent risk factor for AdV disease was identified, but patients with AdV disease had a significantly higher mortality compared with those with asymptomatic infection.

Risk factors for Clostridium difficile infection in intestinal transplant recipients during the first year post-transplant

BACKGROUND

Clostridium difficile is the most common cause of healthcare-associated infectious diarrhea. Risk factors for C. difficile infections (CDI) in intestinal transplant recipients (ITR) are not well-defined. The aim of our study was to assess specific risk factors for CDI in ITR.

METHODS

This is a 1:3 case-control study that included 29 ITR who developed CDI (cases) and 87 ITR without CDI (controls) observed during the first year post-transplantation. Wilcoxon rank sum and Fisher's exact tests were used to compare variables. Univariate and multivariable conditional logistic regressions analysis were performed to identify risk factors for CDI.

RESULTS

The multivariable conditional logistic regression analysis showed that proton pump inhibitors (PPI) administration (odds ratio [OR] = 0.06; 95% confidence interval [CI]: 0.007-0.52; P = .01) was the only factor associated with lower rates of CDI. Outcomes for cases vs controls: rejection episodes 24.14% vs 20.69% (P = .7), graft loss 0% vs 2.3% (P = .99), and survival rate 1 year post-transplantation 79.3% (59.6-90.1%) vs 87.2% (78.1-92.7%) (P = .38).

CONCLUSIONS

Proton pump inhibitor administration might be protective for CDI in ITR. Risks factors for CDI might be different in ITR compared to other populations; anatomical differences and medications administered in the post-transplantation period may affect intestinal microbiota.

Impact of Immunoglobulin Therapy in Intestinal Transplant Recipients With Posttransplantation Hypogammaglobulinemia

BACKGROUND

Severe hypogammaglobulinemia (HGG) (IgG <400 mg/dL) following intestinal transplantation is common. Although IgG replacement therapy is commonly used, clinical outcomes associated with increasing IgG levels to >400 mg/dL are not well described.

METHODS

Kaplan-Meier analysis was performed to estimate survival, the log-rank test to compare survival distributions between groups, and the Fisher exact test to determine the association between HGG and rejection.

RESULTS

A total of 23 intestinal transplant (IT) recipients with a median age of 2.3 years (range, 0.7-41 years) at the time of HGG diagnosis were included. The types of transplants were liver-small bowel (73.9%), liver-small bowel-kidney (8.7%), and small bowel only (17.4%). The 3-year survival after the diagnosis of HGG was 50.2% (95% confidence interval [CI] = 28.2%-68.7%). There was no difference in survival (P = .67) when patients were dichotomized based upon IgG level at last follow-up (IgG ≥400 mg/dL, n = 14; and IgG <400 mg/dL, n = 9). There was no also evidence of an association between survival and: total dose (P = .58), frequency (P = .11), and number of IgG doses administered (P = .8). There was no difference in survival between patients receiving (n = 12) or not receiving (n = 11) cytomegalovirus hyperimmunoglobulin (P = .10).

CONCLUSIONS

Improved survival rates were not found in our IT recipients with severe HGG with immunoglobulin therapy to IgG levels of ≥400 mg/dL, even when cytomegalovirus hyperimmunoglobulin was administered.

Colistin, an Old Drug in a New Territory, Solid Organ Transplantation

BACKGROUND

The clinical experience with colistin therapy for multidrug-resistant Gram-negative pathogens in solid organ transplantation is limited.

METHODS

Patients transplanted from January 2003 to July 2011 and treated with intravenous or nebulized colistin were included. Descriptive statistics were used to summarize patients' characteristics and Kaplan-Meier curves for survival analysis.

RESULTS

Fifteen patients were included: 10 adults (median age, 54.6 y; range, 32.2-79.6 y) and 5 children (median age, 3.3 y; range, 1.1-10.4 y). Eight patients had intra-abdominal infections, 3 had pneumonia, and 4 had bacteremia. The infections were diagnosed at a median of 5.9 months (range, 0.8-49.8 mo) after transplantation. Eight patients had coinfections, mainly with enteric pathogens. Pseudomonas aeruginosa was isolated in 13 cases and ESBL Klebsiella oxytoca and ESBL Escherichia coli were isolated in 1 case each. Thirteen patients received concomitant antibiotics with colistin. The median dose of intravenous colistin (13 patients) was 2.7 mg/kg/d (range, 1-4.9 mg/kg/d) and nebulized colistin (2 patients) was 241.7 mg/d (range, 150-333.3 mg/d). Clinical cure was achieved in 9 patients (60%). Four-week survival rate after infection was 86.7% (95% confidence interval, 56.4%-96.5%). There was no difference in the median creatinine clearance in adults (P = .38) or children (P = .88) before and after colistin. One patient had both neurotoxicity and nephrotoxicity, and 1 patient had neurotoxicity only.

CONCLUSIONS

Colistin might be used as an alternate therapy for transplant patients with multidrug-resistant Gram-negative pathogens.

What is the impact of hypogammaglobulinemia on the rate of infections and survival in solid organ transplantation? A meta-analysis

Hypogammaglobulinemia has been described after solid organ transplantation and has been associated with increased risk of infections. The aim of the study was to evaluate the rate of severe hypogammaglobulinemia and its relationship with the risk of infections during the first year posttransplantation. Eighteen studies (1756 patients) that evaluated hypogammaglobulinemia and posttransplant infections were included. The data were pooled using the DerSimonian and Laird random-effects model. Q statistic method was used to assess statistical heterogeneity. Within the first year posttransplantation, the rate of hypogammaglobulinemia (IgG < 700 mg/dL) was 45% (95% CI: 0.34-0.55; Q = 330.1, p < 0.0001), the rate of mild hypogammaglobulinemia (IgG = 400-700 mg/dL) was 39% (95% CI: 0.22-0.56; Q = 210.09, p < 0.0001) and the rate of severe hypogammaglobulinemia (IgG < 400 mg/dL) was 15% (95% CI: 0.08-0.22; Q = 50.15, p < 0.0001). The rate of hypogammaglobulinemia by allograft type: heart 49% (21%-78%; Q = 131.16, p < 0.0001); kidney 40% (30%-49%; Q = 24.55, p = 0.0002); liver 16% (0.001%-35%; Q = 14.31, p = 0.0002) and lung 63% (53%-74%; Q = 6.85, p = 0.08). The odds of respiratory infection (OR = 4.83; 95% CI: 1.66-14.05; p = 0.004; I(2) = 0%), CMV (OR = 2.40; 95% CI: 1.16-4.96; p = 0.02; I(2) = 26.66%), Aspergillus (OR = 8.19; 95% CI: 2.38-28.21; p = 0.0009; I(2) = 17.02%) and other fungal infections (OR = 3.69; 95% CI: 1.11-12.33; p = 0.03; I(2) = 0%) for patients with IgG < 400 mg/dL were higher than the odds for patients with IgG > 400 mg/dL. The odds for 1-year all-cause mortality for severe hypogammaglobulinemia group was 21.91 times higher than those for IgG > 400 mg/dL group (95% CI: 2.49-192.55; p = 0.005; I(2) = 0%). Severe hypogammaglobulinemia during the first year posttransplantation significantly increased the risk of CMV, fungal and respiratory infections, and was associated with higher 1-year all-cause mortality.

What is the efficacy and safety of colistin for the treatment of ventilator-associated pneumonia? A systematic review and meta-regression

BACKGROUND

Experience with intravenous and aerosolized forms of colistin for the treatment of ventilator-associated pneumonia (VAP) in patients without cystic fibrosis is limited. We aimed to assess the safety and efficacy of colistin for the treatment of VAP.

METHODS

We searched MEDLINE and Cochrane Database of Systematic Reviews for studies comparing colistin vs other antibiotics for treatment of VAP in patients without cystic fibrosis. QUOROM guidelines were followed, the I(2) method was used for heterogeneity, and a random-effects model for odds ratio (OR) estimates.

RESULTS

Six controlled studies met the inclusion criteria. Clinical response did not differ significantly between colistin and control groups (OR, 1.14; 95% confidence interval [CI], .74-1.77; P = .56; I(2) = 0%). The efficacy of colistin was independent of study design (prospective OR, 0.89 [95% CI, .48-1.66; P = .71; I(2) = 0%]; retrospective OR, 1.45 [95% CI, .79-2.68; P = .23; I(2) = 0%]); randomized trials OR, 0.86 [95% CI, .43-1.74; P = .68; I(2) = 0%]). There was no indication of a significant change in clinical response after controlling for concomitant antibiotic treatment (intercept, 0.121; slope, 0.0315; P = .95). Treatment with colistin vs controls did not affect hospital mortality (OR, 0.92; 95% CI, .50-1.67; P = .78; I(2) = 34.59%) or nephrotoxicity (OR, 1.14; 95% CI, .59-2.20; P = .69; I(2) = 0%). Fourteen single-arm studies have been analyzed, and the results were in concordance with the findings of the controlled studies.

CONCLUSIONS

Our results suggest that colistin may be as safe and as efficacious as standard antibiotics for the treatment of VAP.

Incidence, risk factors, and outcomes associated with cytomegalovirus disease in small bowel transplant recipients

Despite improved prophylaxis, monitoring, and more efficient immunosuppression, CMV infection remains a common opportunistic infection in transplant recipients. We assessed the incidence of CMV disease in pediatric SBT recipients, the timing of CMV disease after transplantation, and its impact on patient outcome. The medical records of 98 SBT recipients were reviewed. We performed descriptive analysis, regression analysis, and Kaplan-Meier curves to determine the time-to-event after transplantation. Fifty-three percent patients were male and 47% female, with a mean age of 38.3 months. Thirty-five percent of patients received prophylactic VGC, 55% GCV, 10% a combination of GCV/VGC, and 99% CMV immunoglobulins. A total of 24.5% recipients were CMV D+/R- (CMV serostatus donor positive/recipient negative). Seven (c. 7%) patients developed CMV disease. CMV disease was associated with 2.5 times (0.52-12.1; p = 0.25) higher rate of CMV mismatch and 11.1 times (1.3-95.9; p = 0.03) higher risk of death. CMV prophylaxis increased time-to-death (p = 0.074). Time-to-CMV disease was shorter in patients with enteritis (p < 0.0001), and CMV disease was associated with shorter time-to-death after transplantation (p = 0.001). CMV disease in SBT recipients was associated with an 11-fold mortality increase and a fourfold faster time-to-death. Time-to-death was significantly shorter with CMV enteritis.

Staphylococcus aureus infections after liver transplantation

BACKGROUND

More data on the risk factors and outcomes after Staphylococcus aureus infections in liver transplantation are needed.

METHODS

Liver recipients with S. aureus infections (cases) were retrospectively identified and compared to gender-, age-, and transplant type-matched (1:2) non-S. aureus-infected controls. Risk factors associated with S. aureus infections were identified by conditional logistic regression analysis.

RESULTS

We evaluated 51 patients (median age 52 years). First S. aureus infections developed at a median time of 29 days after transplantation, with 52.94% of them in the first month; 88.24% were nosocomial, 41.18% were polymicrobial, and 47.06% were caused by methicillin-resistant S. aureus (MRSA). Surgical site infections represented 58.82% and bacteremia 23.53%. By univariate analysis, patients with S. aureus infections were intubated more frequently (odds ratio [OR] 26.92, 95% confidence interval [CI] 3.23-3,504.15, p = 0.0006), had a central line (OR 11.69, 95% CI 1.42-95.9, p = 0.02), or recent surgery (OR 26.92, 95% CI 3.23-3,504.15, p = 0.0006) compared with controls. By multivariate analysis, subjects who underwent surgery within 2 weeks prior to infection had a 26.9 times higher risk of developing S. aureus infection (95% CI 3.23-3,504.15, p = 0.0006); these results were adjusted for matched criteria. S. aureus infections did not affect graft or patient survival, but the study was not powered for such outcomes.

CONCLUSION

Only recent surgical procedure was found to be a significant independent risk factor for S. aureus infections after liver transplantation.

Enterococcus pneumonia complicated with empyema and lung abscess in an HIV-positive patient. Case report and review of the literature

This report describes the first case of vancomycin-resistant Enterococcus pneumonia complicated with empyema and lung abscess in an HIV patient and reviews previously published cases of Enterococcus pleuro-pulmonary infection. Our case highlights the rarity of this entity and reviews the risk factors for Enterococcus pleuro-pulmonary infections.

Effects of prolonged use of azithromycin in patients with cystic fibrosis: a meta-analysis

Azithromycin has been studied as potential therapeutic anti-inflammatory agent for cystic fibrosis (CF) patients. Azithromycin (AZM) has been used as an immunomodulating agent, based on few small studies. Considering the cost and potential side effects of long-term azithromycin therapy, it is important to identify the group of patients that would benefit the most. Weighted mean difference was used for pulmonary function tests, and risk ratios for all other variables. The random-effects model was applied for all reports. Combining four studies (N=368), azithromycin showed increase in FEV(1) (3.53%, 95% CI 0.00, 7.07, p=0.05; I(2)=38%) and FVC (4.24%, 95% CI 2.02, 6.45, p=0.0002; I(2)=0%). When trials were analyzed by baseline Pseudomonas sputum colonization, the heterogeneity decreased (I(2)=0%), FEV(1) significantly increased to 4.66% (95% CI 1.18, 8.15, p=0.009), and FVC increased to 4.64% (95% CI 2.11, 7.17, p=0.0003). The GI side effects were 72% higher with azithromycin use (RR 1.72, 95% CI 1.33, 2.21, p=0.00003), the main side effects being nausea (RR 2.04, 95% CI 1.19, 3.45, p=0.009), and diarrhea (RR 2.12, 95% CI 1.10, 4.08, p=0.02). Azithromycin improves lung function of CF patients, especially in the subgroup colonized with Pseudomonas. However, nausea and diarrhea are significantly more frequent with azythromycin.

Sepsis and solid organ transplantation

Approximately seventy patients undergo solid organ transplantation (SOT) every day in the United States. Sepsis remains the first or second most common cause of death in transplant recipients, depending on the allograft type. The rapid diagnosis and treatment of sepsis is critical to ensure improved survival outcome in this special patient population. However, these patients frequently lack the classic systemic inflammatory response syndrome (SIRS), commonly seen in the immunocompetent patients. In order to minimize delays in the diagnosis of sepsis in SOT recipients, it is paramount to recognize the specific risk factors for infection associated with each allograft type. In addition, the particular surgical techniques involved in each type of transplantation may be closely related to the clinical manifestations of the infection process. This correlation can further advance the diagnosis and treatment of sepsis. In conclusion, precocious diagnosis, rapid initiation of antibiotics, surgical correction when necessary, and reduction of immunosuppression, are the mainstream approach to sepsis in the SOT patient. The recent developments in severe sepsis are discussed in the context of the transplant recipient.

Histoplasmosis in solid organ transplant recipients at a large Midwestern university transplant center

Histoplasma capsulatum sporadically causes severe infections in solid organ transplant (SOT) patients in the Midwest, but it has been an unusual infection among those patients followed at the University of Nebraska Medical Center (UNMC), located at the western edge of the 'histo belt.' Nine SOT patients with histoplasmosis are described (6 renal or renal-pancreas and 3 liver recipients) who developed severe histoplasmosis over a recent 2.5-year period at UNMC. Symptoms started a median of 11 months (range, 1.2-90 months) after organ transplant and consisted primarily of fever, cough, shortness of breath, and malaise or fatigue present for approximately 30 days prior to medical evaluation. All patients had an abnormal chest radiograph and/or computed tomographic scan. Tacrolimus was the main immunosuppressant in all 9 patients, along with prednisone or mycophenolate. Dacluzimab or thymoglobulin had been given around the time of transplant in 6 of 9. None was treated for an episode of acute rejection within 2 months before onset of histoplasmosis, although 2 were on high-dose immunosuppression after recent transplants. Diagnosis was made by culture in 8 of the 9 patients, with positive serum and urine histoplasma antigen tests in all 9 cases. From 1997 to 2001, during a period of relative quiescence of the disease in the general population, the rate of clinical histoplasmosis among SOT patients at UNMC was estimated at 0.11%, whereas during 2002 through the first half of 2004, the rate rose 17-fold to 1.9%. Histoplasmosis can present as a prolonged febrile illness with subacute pulmonary symptoms in a cohort of SOT patients, despite the absence of a regional outbreak.

[Vitamin A deficiency in children of national migrants in transit through the Capital of the State of São Paulo, Brazil. A clinico-biochemical study]

Realizaram-se exames clínico-nutricionais e bioquímicos em 109 crianças, de 2 a 7 anos de idade, filhos de migrantes nacionais em trânsito pela Central de Triagem e Encaminhamento (CETREN), na Capital do Estado de São Paulo, Brasil, em que se pesquisaram sinais clínicos de xeroftalmia e níveis sanguíneos de caroteno e vitamina A. As conclusões apontaram existir hipovitaminose A a nível bioquímico, no grupo estudado, não constituindo a xeroftalmia um problema de saúde pública.

[Clinical riboflavin deficiency in pre-school children of migrants in transit through the Central de Triagem e Encaminhamento, in the Capital of the State of São Paulo, Brazil]

Foi realizado um levantamento clínico entre 109 pré-escolares, filhos de migrantes em trânsito pela Central de Triagem e Encaminhamento (CETREN), tendo-se constatado altíssima prevalência de arriboflavinose. A única medida factível foi a administração de riboflavina a todas as crianças examinadas.