The impact of 30-day antecedent antibiotic exposure on Clostridioidesdifficile ribotype patterns and the relationship with clinical outcomes: A single center study.

BACKGROUND: Antibiotic exposure is a known risk factor for Clostridioides difficile infection (CDI) and recurrence and can lead to infection with specific C. difficile strains. In this study, we sought to explore the relationship between antecedent antibiotic exposure and C. difficile antimicrobial resistance, and the impact of resistance on clinical outcomes. METHODS: This was a single center retrospective study evaluating patients with CDI between 2011 and 2021. A logistic regression model was used to evaluate the relationship between antecedent antibiotics in the 30 days prior to CDI and resistance among isolates. In addition, an exploratory analysis using a cause-specific Cox proportional hazards model evaluated the association between resistance and a composite outcome of clinical failure, relapse at 30 days or CDI-related death. RESULTS: we analyzed one isolate from 510 patients; resistance was noted in 339 (66.5 %) of the isolates. Exposure to fluoroquinolones and macrolides was associated with 2.4 (95 % CI 1.4-4.4) and 4.7 (95 % CI 1.1-20.5) increased odds of having resistance compared to other antibiotic class exposure, respectively. There were 58 (17.0 %) patients in the resistance group who developed the composite outcome and 24 (14.2 %) patients who lacked resistance who developed the composite outcome (HR 1.32, 95 % CI 0.81-2.14). CONCLUSION: These findings suggest that fluoroquinolone and macrolide exposure were significantly associated with isolating a resistant strain, but we did not find significant differences in clinical outcomes based on the presence of antimicrobial resistance.

The clinical effectiveness of Fidaxomicin compared to Vancomycin in the treatment of Clostridioides difficile infection, a single center real-world experience.

BACKGROUND: The use of fidaxomicin is recommended as first line therapy for all patients with Clostridioides difficile infection (CDI). However, real-world studies have shown conflicting evidence of superiority. METHODS: We conducted a retrospective single center study of patients diagnosed with CDI between 2011-2021. A primary composite outcome of clinical failure, 30-day relapse or CDI-related death was used. A multivariable cause specific Cox proportional hazards model was used to evaluate fidaxomicin compared to vancomycin in preventing the composite outcome. A separate model was fit on a subset of patients with C. difficile ribotypes adjusting for ribotype. RESULTS: There were 598 patients included, of whom 84 received fidaxomicin. The primary outcome occurred in 8 (9.5%) in the fidaxomicin group compared to 111 (21.6%) in the vancomycin group. The adjusted multivariable model showed fidaxomicin was associated with 63% reduction in the risk of the composite outcome compared to vancomycin (HR = 0.37, 95% CI 0.17-0.80). In the 337 patients with ribotype data after adjusting for ribotype 027, the results showing superiority of fidaxomicin were maintained (HR = 0.19, 95% CI 0.05-0.77). CONCLUSION: In the treatment of CDI, we showed that real-world use of fidaxomicin is associated with lower risk of a composite endpoint of treatment failure.

Comparative Effectiveness of Fidaxomicin vs Vancomycin in Populations With Immunocompromising Conditions for the Treatment of Clostridioides difficile Infection: A Single-Center Study.

Background: Clostridioides difficile infection (CDI) is a leading cause of morbidity in immunocompromised hosts with increased risk of complications and recurrences. In this study, we examined the clinical effectiveness of fidaxomicin vs vancomycin in treating CDI in this patient population. Methods: This single-center retrospective study evaluated patients with CDI between 2011 and 2021. The primary outcome was a composite of clinical failure, relapse at 30 days, or CDI-related death. A multivariable cause-specific Cox proportional hazards model was used to test the relationship between treatment and the composite outcome, adjusting for confounders and treating death from other causes as a competing risk. Results: This study analyzed 238 patients who were immunocompromised and treated for CDI with oral fidaxomicin (n = 38) or vancomycin (n = 200). There were 42 composite outcomes: 4 (10.5%) in the fidaxomicin arm and 38 (19.0%) in the vancomycin arm. After adjustment for sex, number of antecedent antibiotics, CDI severity and type of immunosuppression, fidaxomicin use significantly decreased the risk of the composite outcome as compared with vancomycin (10.5% vs 19.0%; hazard ratio, 0.28; 95% CI, .08-.93). Furthermore, fidaxomicin was associated with 70% reduction in the combined risk of 30- and 90-day relapse following adjustment (hazard ratio, 0.27; 95% CI, .08-.91). Conclusions: The findings of this study suggest that the use of fidaxomicin for treatment of CDI reduces poor outcomes in patients who are immunocompromised.

A Clinical Model to Predict the Occurrence of Select High-risk Infections in the First Year Following Heart Transplantation.

Background: Invasive infection remains a dangerous complication of heart transplantation (HT). No objectively defined set of clinical risk factors has been established to reliably predict infection in HT. The aim of this study was to develop a clinical prediction model for use at 1 mo post-HT to predict serious infection by 1 y. Methods: A retrospective cohort study of HT recipients (2000-2018) was performed. The composite endpoint included cytomegalovirus (CMV), herpes simplex or varicella zoster virus infection, blood stream infection, invasive fungal, or nocardial infection occurring 1 mo to 1 y post-HT. A least absolute shrinkage and selection operator regression model was constructed using 10 candidate variables. A concordance statistic, calibration curve, and mean calibration error were calculated. A scoring system was derived for ease of clinical application. Results: Three hundred seventy-five patients were analyzed; 93 patients experienced an outcome event. All variables remained in the final model: aged 55 y or above, history of diabetes, need for renal replacement therapy in first month, CMV risk derived from donor and recipient serology, use of induction and/or early lymphodepleting therapy in the first month, use of trimethoprim-sulfamethoxazole prophylaxis at 1 mo, lymphocyte count under 0.75 × 103cells/µL at 1 mo, and inpatient status at 1 mo. Good discrimination (C-index 0.80) and calibration (mean absolute calibration error 3.6%) were demonstrated. Conclusion: This model synthesizes multiple highly relevant clinical parameters, available at 1 mo post-HT, into a unified, objective, and clinically useful prediction tool for occurrence of serious infection by 1 y post-HT.

Sex- and age-based comparison of serum immunoglobulins following liver transplantation.

BACKGROUND: Over a quarter of organ transplant recipients have low immunoglobulin levels in their early post-transplant course, which is associated with increased risk of infection and mortality. Although immunoglobulin level varies by sex among healthy individuals, it is unknown how such differences are affected by transplant-related immunosuppression. This study compared post-liver transplant immunoglobulin G (IgG) between sexes at varying ages. METHODS: Serum specimens from a prospective cohort of 130 liver transplant recipients were analyzed. IgG was measured at time of transplant and from one-month post-transplant samples. Post-transplant IgG was compared between sexes using multivariable linear regression. Four age and sex categories were created (women<50, women≥50, men<50, men≥50) and the model repeated with this as the explanatory variable. The relationship between sex hormone concentrations and post-transplant IgG was also explored. Infection type and incidence were examined within groups. RESULTS: The cohort included 99 men, 31 women (mean age 53). In adjusted linear regression, post-transplant IgG was not significantly different by sex (p = 0.92). However, when broken into four categories by age and sex, the contrast in IgG levels between younger versus older patients was strikingly greater among women than among men. An interaction term including age and sex was statistically significant (p = 0.03). The combined age-sex categorical variable was also significantly associated with post-transplant IgG (p = 0.01). Finally, an association was identified between baseline estradiol level and post-transplant change in IgG (p = 0.04). CONCLUSIONS: Sex and age have an important relationship with post-transplant IgG with older women demonstrating lowest concentrations. Immunoglobulin levels have previously demonstrated association with post-transplant outcomes.

Female sex and advanced age are associated with invasive cytomegalovirus disease in solid organ transplant recipients.

BACKGROUND: Limited data exist to describe sex-based differences in the severity of cytomegalovirus (CMV) infection after solid organ transplant (SOT). We sought to identify if a difference exists in likelihood of tissue-invasive disease between male and female SOT recipients and to understand how age affects this relationship. METHODS: A retrospective cohort of 180 heart, liver, and kidney recipients treated for CMV was examined. A logistic regression model was developed to assess the relationship between female sex and CMV type (noninvasive vs. invasive). A secondary regression analysis looked at the relationship of invasive CMV with a variable combining sex with age above or below 50. RESULTS: There were 37 cases of proven or probable invasive CMV, occurring in 30% of females versus 16% of males. After adjustment for potential confounders, females with CMV infection were significantly more likely to have invasive disease (odds ratio (OR) 2.69, 95% confidence interval (CI) 1.25-5.90, p = .01). Females 50 years or older were at particular risk compared with males under 50 years (adjusted OR 4.54, 95% CI 1.33-18.83, p = .02). CONCLUSION: Female SOT recipients with CMV in our cohort were more likely than males to have tissue-invasive disease, with the highest risk among older females. Further prospective studies are warranted to explore underlying immunologic mechanisms.

Difference in absolute lymphocyte count among male and female heart transplant recipients.

The impact of sex on immune composition in the setting of solid organ transplantation is unknown. Immunocompetent men and women have quantitative differences in multiple markers of immunity, including lymphocyte subsets. Lymphocytes are of particular interest given the routine use of medications targeted at cell-mediated immunity. The objective of this retrospective cohort study was to compare absolute lymphocyte count (ALC) measurements of male and female heart recipients immediately before, and 1 month after, transplantation. Data was collected on 375 adult recipients (104 female and 271 male) from 2000 to 2018 at a single center. Mean ALC was compared using Student's t-test. Women had higher mean ALC both at baseline (female 1.6 × 103 cells/µl vs. male 1.3 × 103 cells/µl; P < .001) and at 1 month post-transplantation (mean 1.2 × 103 cells/µl vs. .8 × 103 cells/µl; P < .001). This finding could have important implications for sex-based differences in predisposition to rejection or response to infection or vaccination.

Factors associated with neutropenia post heart transplantation.

BACKGROUND: Neutropenia is a serious complication following heart transplantation (OHT); however, risk factors for its development and its association with outcomes is not well described. We sought to study the prevalence of neutropenia, risk factors associated with its development, and its impact on infection, rejection, and survival. METHODS: A retrospective single-center analysis of adult OHT recipients from July 2004 to December 2017 was performed. Demographic, laboratory, medication, infection, rejection, and survival data were collected for 1 year post-OHT. Baseline laboratory measurements were collected within the 24 hours before OHT. Neutropenia was defined as absolute neutrophil count ≤1000 cells/mm3. Cox proportional hazards models explored associations with time to first neutropenia. Associations between neutropenia, analyzed as a time-dependent covariate, with secondary outcomes of time to infection, rejection, or death were also examined. RESULTS: Of 278 OHT recipients, 84 (30%) developed neutropenia at a median of 142 days (range 81-228) after transplant. Factors independently associated with increased risk of neutropenia included lower baseline WBC (HR 1.12; 95% CI 1.11-1.24), pre-OHT ventricular assist device (1.63; 1.00-2.66), high-risk CMV serostatus [donor positive, recipient negative] (1.86; 1.19-2.88), and having a previous CMV infection (4.07; 3.92-13.7). CONCLUSIONS: Neutropenia is a fairly common occurrence after adult OHT. CMV infection was associated with subsequent neutropenia, however, no statistically significant differences in outcomes were found between neutropenic and non-neutropenic patients in this small study. It remains to be determined in future studies if medication changes in response to neutropenia would impact patient outcomes.

Association Between Lymphopenia at 1 Month Posttransplant and Infectious Outcomes or Death in Heart Transplant Recipients.

BACKGROUND: Cell-mediated immunity is a specific target of several medications used to prevent or treat rejection in orthotopic heart transplantation. Low absolute lymphocyte count (ALC) has potential to be a useful and accessible clinical indicator of overall infection risk. Though some studies have demonstrated this association in other transplant populations, it has not been assessed in heart transplant recipients. METHODS: A single-center retrospective cohort study examined adult heart transplant recipients transplanted between 2000 and 2018. The exposure of interest was ALC ≤0.75 × 103 cells/µL at 1 month posttransplant, and the primary endpoint was a composite outcome of infection (including cytomegalovirus [CMV], herpes simplex I/II or varicella zoster virus [HSV/VZV], bloodstream infection [BSI], invasive fungal infection [IFI]) or death occurring after 1 month and before 1 year posttransplant. A multivariable Cox proportional hazards model was created to control for confounders identified using clinical judgment and statistical criteria. RESULTS: Of 375 subjects analyzed, 101 (27%) developed the composite outcome (61 CMV, 3 HSV/VZV, 19 BSI, 10 IFI, 8 deaths). Lymphopenia (ALC ≤0.75 × 103 cells/µL) at 1 month was associated with a >2-fold higher rate of the composite outcome (hazard ratio [HR], 2.26 [95% confidence interval {CI}, 1.47-3.46]; P < .001) compared to patients without lymphopenia at 1 month. After adjustment for confounding variables, the presence of lymphopenia remained statistically significantly associated with the composite outcome (HR, 1.72 [95% CI, 1.08-2.75]; P = .02). CONCLUSIONS: ALC measured at 1 month after heart transplant is associated with an increased risk of infectious outcomes or death in the ensuing 11 months. This is a simple, accessible laboratory measure.

The impact of recurrent cytomegalovirus infection on long-term survival in solid organ transplant recipients.

BACKGROUND: Cytomegalovirus (CMV) remains a significant contributor to morbidity and mortality following solid organ transplantation (SOT). While recurrent infection occurs in up to 30% of patients, its impact on mortality is unclear. The aim of this study was to explore the relationship between recurrent CMV infection and long-term survival in SOT recipients. METHODS: We performed a retrospective cohort study of SOT recipients who completed treatment for an episode of CMV infection. Patients were followed until death, loss to follow-up or 10 years following CMV treatment completion. Univariable and multivariable hazard ratios (HR) were calculated, treating relapse and rejection following CMV as time-varying. RESULTS: About 79 kidney, 52 heart, 34 liver, and 5 liver-kidney transplant recipients were included. About 62/170 died, at a median of 3.8 years (IQR 0.8-6.6 years). Median follow-up among the 108 survivors was 7.4 years (IQR 3.7-10 years). Recurrent CMV infection occurred in 49/170 (29%), 67% within 6 months of treatment completion. Mortality among those who relapsed was 39% (19/49) vs 36% (43/121) in those who remained relapse-free (unadjusted HR 1.59, 95% CI 0.92-2.75, P = .10). After adjusting for age and transplanted organ, findings were similar (HR 1.68, 95% CI 0.93-3.04, P = .09). CONCLUSIONS: Mortality following CMV remains high even in the valganciclovir era. Although our findings suggest a possible increased risk of death among patients with recurrent CMV, these did not reach statistical significance. The complex nature of these patients, multiple potential confounders, and limited statistical power made detection of small effects difficult. Larger prospective studies evaluating the clinical impact of strategies to reduce recurrence are needed.

Reactivation of latent cytomegalovirus infection in patients with rheumatologic disease: a case-control study.

The disease burden, risk factors and clinical sequelae of CMV reactivation in patients with rheumatologic conditions is poorly understood. We have described a cohort with underlying rheumatic disease and CMV, and compared a subgroup with systemic lupus erythematosus (SLE) to controls to identify potential risk factors for CMV reactivation. Adults with rheumatic disease and CMV infection from 2000-2015 were identified. SLE cases were matched 3:1 with controls based on age, sex and year of admission, and compared. Fourteen patients were included (6 SLE, 4 rheumatoid arthritis, 2 sarcoidosis, 1 psoriatic arthritis, 1 microscopic polyangiitis). Seven had viremia alone, the remainder tissue-invasive disease. Thirteen received glucocorticoids prior to CMV reactivation. Fever was the most common symptom, and coinfections were seen in eight including four with bacteremia. Thirteen received antiviral therapy (median 33 days), four died during hospitalization. Six patients with underlying SLE and CMV reactivation were compared to 18 SLE controls. Cases received more glucocorticoids prior to admission (median 36.5 vs. 2.5 mg/day, p = 0.006), had longer hospitalizations (median 47 vs. 7 days, p = 0.006) and more coinfections (67% vs. 17%, p = 0.04). There were no significant differences in symptoms at presentation. CMV reactivation occurs in patients with rheumatologic disease, can result in severe clinical sequelae, and is difficult to distinguish from a flare of the underlying disease. Patients with CMV received higher doses of glucocorticoids and developed more co-infections. CMV should be considered during the evaluation of a febrile illness in this complex patient population.

Reactivation of Latent Cytomegalovirus Infection after Major Surgery: Risk Factors and Outcomes.

Background: Reactivation of latent cytomegalovirus (CMV) infection occurs in previously immunocompetent critically ill individuals and may be associated with increased morbidity and mortality. Our aim was to explore risk factors for and outcomes after CMV reactivation in patients undergoing major surgery. Patients and Methods: We performed a retrospective case control study of patients without underlying immunocompromise who developed post-operative CMV reactivation from 2004-2016. Cases included patients testing positive for CMV by viral load, culture, or histopathology. Controls were matched by age, gender, type, and year of surgery. Results: Sixteen CMV cases were matched to 32 controls. Median age was 65 and median time from surgery to CMV diagnosis was 32 days. Symptoms included fever (94%), hepatitis (75%), myelosuppression (56%), and diarrhea (38%). Despite similar baseline comorbidities, cases were more likely to return to surgery (odds ratio [OR] 6.31; 95% confidence interval [CI], 1.29-30.74), require renal replacement therapy (OR 18.54; 95% CI, 2.36-145.6), total parenteral nutrition (OR 33.0; 95% CI, 6.60-262.37) and corticosteroids (OR 18.78; 95% CI, 4.5-103.9). Length of stay was increased (median 51 vs. 8 days, p = 0.005), co-infections were more common (OR 15.10; 95% CI, 1.89-120.8), and mortality was higher (38% vs. 0%, p < 0.01). Conclusions: Cytomegalovirus reactivation occurs in previously immunocomptent patients post-operatively and is associated with poor outcomes including other infections and mortality. Potential risk factors include prolonged length of stay, surgical complications, and corticosteroid use. It is not clear from our study whether CMV reactivation is a surrogate marker of severe illness and post-operative complications or if CMV reactivation plays a causative role in the development of these adverse outcomes.

Correlation of Cytomegalovirus (CMV) Disease Severity and Mortality With CMV Viral Burden in CMV-Seropositive Donor and CMV-Seronegative Solid Organ Transplant Recipients.

BACKGROUND: The rate of cytomegalovirus (CMV) viral load increase and peak viral loads are associated with CMV disease in kidney and liver transplant recipients, but relationships to disease severity or mortality have not been shown. METHODS: Using stored serial serum specimens from renal (n = 59) and liver (n = 35) transplant recipients (D+R-; CMV-seropositive donors, CMV-seronegative recipients) from 2 prospective, randomized, controlled, interventional prophylaxis trials of CMV immune globulin (CMVIG), CMV viral load was measured using the COBAS quantitative polymerase chain reaction assay and the World Health Organization CMV standard. Patients with severe CMV-associated disease were classified according to trial definitions. Pairwise comparisons of mean viral load among deceased, surviving diseased, and nondiseased patients were analyzed by 2-way analysis of variance. To determine if viral load could predict mortality, receiver operating characteristic (ROC) curves were constructed using area under the curve (AUC) of the viral load and peak viral concentration (Vmax). RESULTS: Viral load (mean log10 [AUC], peak viral load [Vmax]) for patients with severe CMV disease was significantly higher compared with nondiseased patients (P < .001). Similarly, higher viral burden was significantly associated with mortality (P < .001). Viral load AUC and Vmax AUROCs for predicting mortality were 0.796 and 0.824, respectively, for renal patients, and 0.769 and 0.807, respectively, for liver patients. CONCLUSIONS: Using specimens from studies preceding the antiviral prophylaxis era, CMV viral load was associated with severe CMV disease and death, supporting CMV viral load quantification as a proxy for CMV disease severity and disease-associated mortality end points in solid organ transplantation.

Absolute Lymphocyte Count: A Predictor of Recurrent Cytomegalovirus Disease in Solid Organ Transplant Recipients.

Background: Recurrent cytomegalovirus (CMV) disease in solid organ transplant recipients frequently occurs despite effective antiviral therapy. We previously demonstrated that patients with lymphopenia before liver transplantation are more likely to develop posttransplant infectious complications including CMV. The aim of this study was to explore absolute lymphocyte count (ALC) as a predictor of relapse following treatment for CMV disease. Methods: We performed a retrospective cohort study of heart, liver, and kidney transplant recipients treated for an episode of CMV disease. Our primary outcome was time to relapse of CMV within 6 months. Data on potential predictors of relapse including ALC were collected at the time of CMV treatment completion. Univariate and multivariate hazard ratios (HRs) were calculated with a Cox model. Multiple imputation was used to complete the data. Results: Relapse occurred in 33 of 170 participants (19.4%). Mean ALC in relapse-free patients was 1.08 ± 0.69 vs 0.73 ± 0.42 × 103 cells/µL in those who relapsed, corresponding to an unadjusted hazard ratio of 1.11 (95% confidence interval, 1.03-1.21; P = .009, n = 133) for every decrease of 100 cells/µL. After adjusting for potential confounders, the association between ALC and relapse remained significant (HR, 1.11 [1.03-1.20]; P = .009). Conclusions: Low ALC at the time of CMV treatment completion was a strong independent predictor for recurrent CMV disease. This finding is biologically plausible given the known importance of T-cell immunity in maintaining CMV latency. Future studies should consider this inexpensive, readily available marker of host immunity.

Role of Secondary Prophylaxis With Valganciclovir in the Prevention of Recurrent Cytomegalovirus Disease in Solid Organ Transplant Recipients.

BACKGROUND: Cytomegalovirus (CMV) is a major contributor to morbidity and mortality in solid organ transplant recipients (SOTRs). Ganciclovir and valganciclovir are highly effective antiviral drugs with a well-established role in primary prophylaxis and treatment of CMV disease. Our objective in this study was to examine the effect of secondary prophylaxis (SP) on the risk of relapse in SOTRs following an episode of CMV disease. METHODS: We performed a retrospective cohort study of SOTRs from 1995 to 2015 and used propensity score-based inverse probability of treatment weighting methodology to control for confounding by indication. A weighted Cox model was created to determine the effect of SP on time to relapse within 1 year of treatment completion. RESULTS: Fifty-two heart, 34 liver, 79 kidney, and 5 liver-kidney transplant recipients who completed treatment for an episode of CMV infection/disease were included. A total of 120 (70.6%) received SP (median duration, 61 days; range, 5-365) and 39 (23%) relapsed. SP was protective against relapse from 0 to 6 weeks following treatment completion (hazard ratio [HR], 0.19; 95% confidence interval [CI], 0.05-0.69). However, after 6 weeks, risk of relapse did not significantly differ between the 2 groups (HR, 1.18; 95% CI, 0.46-2.99). CONCLUSIONS: Our findings demonstrate that use of SP following treatment of CMV disease did not confer long-term protection against relapse, although it did delay relapse while patients were receiving antivirals. This suggests that SP has limited clinical utility in the overall prevention of recurrent CMV disease.

Iron-related markers are associated with infection after liver transplantation.

Though serum iron has been known to be associated with an increased risk of infection, hepcidin, the major regulator of iron metabolism, has never been systematically explored in this setting. Finding early biomarkers of infection, such as hepcidin, could help identify patients in whom early empiric antimicrobial therapy would be beneficial. We prospectively enrolled consecutive patients (n = 128) undergoing first-time, single-organ orthotopic liver transplantation (OLT) without known iron overload disorders at 2 academic hospitals in Boston from August 2009 to November 2012. Cox regression compared the associations between different iron markers and the development of first infection at least 1 week after OLT; 47 (37%) patients developed a primary outcome of infection at least 1 week after OLT and 1 patient died. After adjusting for perioperative bleeding complications, number of hospital days, and hepatic artery thrombosis, changes in iron markers were associated with the development of infection post-OLT including increasing ferritin (hazard ratio [HR], 1.51; 95% confidence interval [CI], 1.12-2.05), rising ferritin slope (HR, 1.10; 95% CI, 1.03-1.17), and increasing hepcidin (HR, 1.43; 95% CI, 1.05-1.93). A decreasing iron (HR, 1.76; 95% CI, 1.20-2.57) and a decreasing iron slope (HR, 4.21; 95% CI, 2.51-7.06) were also associated with subsequent infections. In conclusion, hepcidin and other serum iron markers and their slope patterns or their combination are associated with infection in vulnerable patient populations. Liver Transplantation 23 1541-1552 2017 AASLD.

Characteristics and outcomes of neutropenia after orthotopic liver transplantation.

Neutropenia after orthotopic liver transplantation (LT) is relatively common, but the factors associated with its development remain elusive. We assessed possible predictors of neutropenia (absolute neutrophil count [ANC] ≤ 1000/mm(3) ) within the first year of LT in a cohort of 304 patients at a tertiary medical center between 1999 and 2009 using time-dependent survival analysis to identify risk factors for neutropenia. In addition, we analyzed neutropenia as a predictor of the clinical outcomes of death, bloodstream infection (BSI), invasive fungal infection, cytomegalovirus (CMV) disease, and graft rejection within the first year of LT. Of the 304 LT recipients, 73 (24%) developed neutropenia, 5 (7%) of whom had grade 4 neutropenia (ANC < 500/mm(3) ). The following were independent predictors for neutropenia: Child-Turcotte-Pugh score (hazard ratio [HR] 1.15; 95% confidence interval [CI], 1.03-1.30; P = 0.02), BSI (HR, 2.89; 95% CI, 1.63-5.11; P < 0.001), CMV disease (HR, 4.28; 95% CI, 1.55-11.81; P = 0.005), baseline tacrolimus trough level (HR, 1.02; 95% CI, 1.01-1.03; P = 0.007), and later era LT (2004-2009 versus 1999-2003; HR, 2.28; 95% CI, 1.43-3.65; P < 0.001). Moreover, neutropenia was found to be an independent predictor for mortality within the first year of LT (HR, 3.76; 95% CI, 1.84-7.68; P < 0.001). In conclusion, our data suggest that neutropenia within a year after LT is not unusual and is an important predictor of mortality.

Pretransplant lymphopenia is a novel prognostic factor in cytomegalovirus and noncytomegalovirus invasive infections after liver transplantation.

Infection after liver transplantation (LT) remains a leading cause of morbidity and mortality. The risk of infection after LT is highest in those who are most immunosuppressed, but to date, no standard blood marker of one's degree of immunosuppression or risk index has been established. The purpose of this study was to determine whether pretransplant lymphopenia (absolute lymphocyte count < 500 cells/mm3 within 24 hours before LT) is a candidate marker of immunosuppression and could be useful in predicting the risk of cytomegalovirus (CMV) disease and non-CMV invasive infections after LT. Data were extracted from medical records for all primary, solitary LT procedures performed at Tufts Medical Center from 1999 to 2009. Two hundred seventy-six patients had sufficient data to be included in the analysis. Among these patients, 52% developed CMV or non-CMV invasive infections within 5 years of LT. Within 2 years, 23 (8%) had CMV disease, and 103 (37%) at least 1 non-CMV invasive infection. More lymphopenic patients than nonlymphopenic patients developed CMV (21% versus 4%, P < 0.001) and non-CMV invasive infections (50% versus 33%, P = 0.02). In a multivariate survival analysis, pretransplant lymphopenia was the strongest independent predictor of CMV disease [hazard ratio (HR) = 5.52, 95% confidence interval (CI) = 2.31-13.1, P = 0.001] after adjustments for known risk factors, including CMV serostatus (HR = 4.72, 95% CI = 2.01-11.1, P < 0.001). Both pretransplant lymphopenia (HR = 1.64, 95% CI = 1.14-2.53, P = 0.03) and CMV (HR = 2.93, 95% CI = 1.23-6.92, P = 0.02) independently predicted non-CMV infections. Our results suggest that pretransplant lymphopenia is a novel independent predictor of both CMV disease and non-CMV invasive infections after LT and is a candidate marker of immunosuppression in LT recipients.

Increased serum iron levels and infectious complications after liver transplantation.

BACKGROUND: Elevated serum iron levels have been associated with infectious outcomes in various patient populations but, to our knowledge, have never been studied after liver transplantation. METHODS: The relationship between serum iron levels and infectious outcomes after liver transplantation was evaluated in a nested case-control study using prospectively collected data and serum samples. Unadjusted and adjusted hazard ratios were calculated for each iron marker predictor variable (iron level, unsaturated iron-binding capacity, total iron-binding capacity, transferrin saturation, and ferritin level) and time to development of each of 6 outcomes (cytomegalovirus [CMV] disease, invasive fungal infection, bacteremia, invasive fungal infection or bacteremia, any infection, and 1-year mortality rate). RESULTS: Serum measurements (n = 109) corresponding to increased levels of serum iron were independently associated with an increased risk of any infection and death. After adjusting for the number of red blood cell transfusions, donor CMV-seropositive status, and fungal colonization, ferritin level was independently associated with the development of any infection (hazard ratio, 1.09; 95% confidence interval, 1.04-1.14). After adjusting for the number of red blood cell transfusions, development of CMV disease, and administration of intravenous steroids for treatment of rejection, ferritin level was also was independently associated with death (hazard ratio, 1.11; 95% confidence interval, 1.04-1.18). Similar results were found for unsaturated iron binding capacity for the same 2 outcomes. CONCLUSIONS: A better understanding of iron metabolism and its relationship to infection could help guide future infection prognosis, prevention, and management efforts in this high-risk population.