Bloodstream infections can develop late (after day 100) and/or in the absence of neutropenia in children receiving allogeneic bone marrow transplantation

Bloodstream bacterial infections in thalassemic pediatric and adolescent patients after hematopoietic stem cell transplantation

BACKGROUND

Thalassemic patients usually require regular blood transfusions; however, HSCT can provide a cure. Incidence of IBI in pediatric patients post-HSCT is still scant.

OBJECTIVES

This study aimed to explore whether thalassemic patients had a different incidence of post-HSCT IBI compared with patients with other underlying diseases. Factors associated with IBI in the pediatric population undergoing HSCT were also investigated.

METHODS

In this retrospective cohort study, clinical data of pediatric patients who underwent HSCT during the period from 2011 to 2016 were reviewed and analyzed. The primary outcome was incidence of IBI within 1-year post-HSCT.

RESULTS

Of 123 patients, 53 were thalassemic. IBI was diagnosed in 23 patients within 1 year after HSCT (incidence: 19.5 episodes/1000 patients/month). The IBI incidence was lower in thalassemic patients than in patients with other underlying diseases (6.9 vs. 31.6 episodes/1000 patients/month). Having thalassemia as an underlying disease was the only factor associated with lower IBI in pediatric post-HSCT patients (hazard ratio: 0.245; 95% confidence interval, 0.080-0.748). In post-HSCT thalassemic patients, IBI mostly occurred within 100 days after HSCT, and most of these cases had catheter-related blood stream infection. The risk of IBI tended higher for haploidentical HSCT, but this difference was not statistically significantly different.

CONCLUSION

The IBI incidence after HSCT was lower in thalassemic patients than in those with other underlying diseases. Catheter-related blood stream infection was the major IBI in these patients. IBI was not a major complication in thalassemic pediatric patients undergoing HSCT.

Microbiology and Risk Factors for Hospital-Associated Bloodstream Infections Among Pediatric Hematopoietic Stem Cell Transplant Recipients

Background

Children undergoing hematopoietic stem cell transplantation (HSCT) are at high risk for hospital-associated bloodstream infections (HA-BSIs). This study aimed to describe the incidence, microbiology, and risk factors for HA-BSI in pediatric HSCT recipients.

Methods

We performed a single-center retrospective cohort study of children and adolescents (<18 years of age) who underwent HSCT over a 20-year period (1997–2016). We determined the incidence and case fatality rate of HA-BSI by causative organism. We used multivariable Poisson regression to identify risk factors for HA-BSI.

Results

Of 1294 patients, the majority (86%) received an allogeneic HSCT, most commonly with umbilical cord blood (63%). During the initial HSCT hospitalization, 334 HA-BSIs occurred among 261 (20%) patients. These were classified as gram-positive bacterial (46%), gram-negative bacterial (24%), fungal (12%), mycobacterial (<1%), or polymicrobial (19%). During the study period, there was a decline in the cumulative incidence of HA-BSI (P = .021) and, specifically, fungal HA-BSIs (P = .002). In multivariable analyses, older age (incidence rate ratio [IRR], 1.03; 95% confidence interval [CI], 1.01–1.06), umbilical cord blood donor source (vs bone marrow; IRR, 1.69; 95% CI, 1.19–2.40), and nonmyeloablative conditioning (vs myeloablative; IRR, 1.85; 95% CI, 1.21–2.82) were associated with a higher risk of HA-BSIs. The case fatality rate was higher for fungal HA-BSI than other HA-BSI categories (21% vs 6%; P = .002).

Conclusions

Over the past 2 decades, the incidence of HA-BSIs has declined among pediatric HSCT recipients at our institution. Older age, umbilical cord blood donor source, and nonmyeloablative conditioning regimens are independent risk factors for HA-BSI among children undergoing HSCT.

Incidence, risk factors, and outcome of blood stream infections during the first 100 days post-pediatric allogeneic and autologous hematopoietic stem cell transplantations

Bloodstream infections (BSI) are a frequently observed complication after hematopoietic stem cell transplant (HSCT). Retrospective analysis of clinical and microbiological data during the first 100 days from 302 consecutive pediatric patients who underwent HSCT for a malignant disease at our institute between January 2013 and June 2017. A total of 164 patients underwent autologous and 138 allogeneic HSCT. The overall incidence of BSI was 37% with 92% of infectious episodes occurring during the pre-engraftment phase. Gram-positive bacteria (GPB) accounted for 54.6% of the isolated pathogens, gram-negative bacteria (GNB) for 43.9%, and fungi for 1.4%. Coagulase-negative staphylococci and Escherichia coli were the most commonly isolated GPB and GNB, respectively. Forty-five percent of GNB were extended-spectrum beta-lactamase producers and 21% were multidrug-resistant organisms. Fluoroquinolone resistance was 92% and 68%, among GPB and GNB, respectively. Risk factors for BSI in univariate analysis were allogeneic HSCT, delayed time to engraftment more than 12 days, previous BSI before HSCT, and alternative donor. In multivariate analysis, only HSCT type (allogeneic vs autologous P = .03) and previous BSI within 6 months before HSCT (P = .016) were significant. Overall survival at day 100 was 98% and did not differ significantly between patients with and without BSI (P = .76). BSI is common in children undergoing HSCT for malignant diseases. Allogeneic HSCT recipients and previous BSI within 6 months before HSCT are associated with increased risk of post-transplant BSI. With current supportive measures, BSI does not seem to confer an increased risk for 100-day mortality.

Bacterial bloodstream infections in pediatric allogeneic hematopoietic stem cell recipients before and after implementation of a central line-associated bloodstream infection protocol: A single-center experience

INTRODUCTION

There are only few reports describing the influence of central line-associated bloodstream infection (CLABSI) prevention strategies on the incidence of bacterial bloodstream infections (BBSIs).

METHODS

We performed a retrospective cohort study among pediatric recipients of allogeneic hematopoietic stem cell transplantation (allo-HCT) to assess potential changes in BBSI rates during 3 time periods: pre-CLABSI prevention era (era 1, 2004-2005), CLABSI prevention implementation era (era 2, 2006-2009), and maintenance of CLABSI prevention era (era 3, 2010-2012). BBSI from day 0-365 following allo-HCT were studied. The comparison of person-years incidence rates among different periods was carried out by Poisson regression analysis.

RESULTS

The mean age of patients was 10.0 years. During the study period, 126 (65%) of 190 patients had at least a single BBSI. From day 0-30, day 31-100, day 101-180, and day 181-365, 20%, 28%, 30%, and 17% of patients, respectively, experienced BBSIs. The rate of Staphylococcus epidermidis and gram-negative pathogens significantly declined from 3.16-0.93 and 6.32-2.21 per 100 person-months during era 1 and era 3, respectively (P = .001).

CONCLUSIONS

Patients undergoing allo-HCT during era 3 were associated with decreased risk of BBSI (P = .012). Maintenance of CLABSI protocols by nursing staff and appropriate education of other care providers is essential to lower incidence of BBSI in this high-risk population, and further strategies to decrease infection burden should be studied.

Bacteremia during neutropenic episodes in children undergoing hematopoietic stem cell transplantation with ciprofloxacin and penicillin prophylaxis

Bacteremia during neutropenic episodes is a cause of morbidity and mortality in patients undergoing hematopoietic stem cell transplantation (HSCT). We have used oral ciprofloxacin and penicillin V, from the start of the conditioning regimen until engraftment, for the prophylaxis of bacterial infection. The objective of this study was to retrospectively analyze the prevalence of and risk factors for breakthrough bacteremia during neutropenic episodes in autologous and allogeneic HSCT patients. There were 215 patients enrolled, with a median age of 8.32 years (range 0.51-21.64 years) between 2002 and 2014. The common underlying diseases were thalassemia and acute leukemia. Bacteremia was documented in 33 patients (15.3 %), with 39 microorganisms isolated. Escherichia coli (28.2 %) and Streptococcus viridans (12.8 %) were the most commonly isolated Gram-negative and Gram-positive bacteria, respectively. Multidrug resistant strains were found in 32 and 14.3 % of Gram-negative and Gram-positive bacteria, respectively. Risk factors for bacteremia were receiving anti-thymocyte globulin (ATG) [odds ratio (OR) 2.44, 95 % confidence interval (CI) 1.06-5.65, P = 0.037] and umbilical cord blood as a stem cell graft (OR 6.60, 95 % CI 1.04-41.83, P = 0.045). In conclusion, the prevalence of bacteremia was 15.3 % and the use of ATG and cord blood were risk factors for bacteremia during neutropenic episodes.

Incidence and risk factors of bacterial infections in children following autologous hematopoietic stem cell transplantation: Single-center experience from Jordan

Bacterial infection is a serious sequela following AHSCT; however, limited data are available regarding pediatric recipients, especially in developing countries. We retrospectively analyzed the incidence and risk factors of bacterial infections during the first 100 days after AHSCT in children at KHCC in Amman, Jordan between January, 2005 and September, 2013. A total of 65 patients were identified, with median age of four yr (1-17). Forty-seven patients (72.3%) had solid tumors and 18 (27.7%) had lymphoma. Bacterial infections were documented in 33 patients (50%), with a total of 63 episodes. Gram-negative infection (57.1%) was more prevalent than Gram-positive infection (38%). The risk of bacterial infections was higher among patients less than five yr of age (p = 0.028) and those who developed hypogammaglobulinemia requiring IVIG replacement (p = 0.001). Patients with solid tumors developed more bacterial infections compared to patients with lymphoma (p = 0.0057). No deaths were attributed to bacterial infection. Bacterial infection rate is high among recipients of AHSCT in Jordan with Gram-negative bacteria being the most common.

Improved Splenic Function After Hematopoietic Stem Cell Transplant for Sickle Cell Disease

BACKGROUND

Splenic dysfunction is a significant complication of sickle cell disease (SCD). Hematopoietic stem cell transplant (HSCT) is a proven cure for SCD; however, its long-term effect on splenic function is not well characterized.

PROCEDURE

We conducted a retrospective cohort study of pediatric patients who had HSCT for SCD at two transplant centers. (99m) Tc liver-spleen (LS) scans were blindly reviewed and classified as demonstrating absent, decreased, or normal splenic uptake.

RESULTS

Considering all engrafted nonsplenectomized Hb SS and Sβ(0) -thalassemia patients with LS scans available, at a median of 2.0 years post-HSCT (range 1.0-9.3 years) eight of 53 (15%) had normal, 40 of 53 (75%) decreased, and five of 53 (9%) absent splenic uptake. More patients had splenic uptake after HSCT: pre-HSCT 14/38 (37%) versus post-HSCT 34/38 (89%), P < 0.0001. Older age at HSCT was associated with worse splenic function post-HSCT (median age at HSCT for absent uptake 16.6 years vs. present uptake 8.0 years, P = 0.030). Extensive chronic GVHD was also more common in patients with absent splenic uptake compared to patients with present uptake (absent 40% vs. present 6%, P = 0.064).

CONCLUSIONS

HSCT significantly improves splenic function for most pediatric patients with SCD, but older patient age at time of HSCT and extensive chronic GVHD appear to be risk factors for poor post-HSCT splenic function.

Bloodstream infection after stem cell transplantation in children with idiopathic aplastic anemia

Bloodstream infection (BSI) is the most common infectious complication of hematopoietic stem cell transplantation (HSCT) and can cause substantial morbidity and mortality. Identification of risk factors for BSI might be helpful in efforts to reduce transplantation-related death. This study analyzed the incidence of BSI and risk factors for BSI after HSCT in pediatric patients with aplastic anemia (AA). BSI occurred in 39 of the 351 patients with AA (11.1%). Onset of BSI occurred at a median of 8 days after HSCT (range, 0 to 92 days). The 5-year overall survival rate was lower in patients with BSI than in patients without BSI (63.32% ± 7.90% versus 93.35% ± 1.44%; P < .0001). Univariate analysis identified the following variables as associated with BSI: history of immunosuppressive therapy with antithymocyte globulin (ATG), transplantation from an unrelated donor, frequent blood transfusion before transplantation, major or major plus minor ABO type mismatch, graft-versus-host disease prophylaxis with tacrolimus and without cyclosporine, and long interval from diagnosis to transplantation. Among these factors, long interval from diagnosis to transplantation was the sole statistically significant risk factor for BSI on multivariate analysis. In patients who underwent HSCT from a related donor, age ≥14 years at transplantation was risk factor for BSI. In contrast, history of immunosuppressive therapy with ATG, frequent blood transfusion before HSCT, graft failure, and major or major plus minor ABO type mismatch were risk factors for BSI in patients who underwent HSCT from an unrelated donor. Because the overall 5-year survival rate without BSI was >90%, even in patients who were received a transplant from an unrelated donor, control of BSI is very important for successful HSCT in pediatric patients with AA.

Risk factor analysis of bloodstream infection in pediatric patients after hematopoietic stem cell transplantation

Bloodstream infection (BSI) is a recognized cause of morbidity and mortality in children after hematopoietic stem cell transplantation (HSCT). However, there are limited reports on BSI after HSCT in pediatric patients in multiple centers. This study was a retrospective cohort analysis of consecutive patients who underwent allogeneic and autologous HSCT at the Department of Paediatrics, Hokkaido University Hospital, between 1988 and 2009; the Department of Paediatrics, Sapporo Hokuyu Hospital, between 2007 and 2009; and the Department of Paediatrics, Asahikawa Medical University, between 1989 and 2009. A total of 277 patients underwent HSCT during the study period. In this multicenter analysis, cases of BSI after HSCT were recorded in the early posttransplant period (within the first 100 d), and BSI was observed in 24 of 277 HSCT patients. Multivariate analysis showed that nonmalignant disease was an independent factor associated with BSI after HSCT (hazard ratio 6.3 for aplastic anemia or Wiskott-Aldrich syndrome patients; confidence interval, 1.4-12.8; P = 0.012). We conclude that aplastic anemia and Wiskott-Aldrich syndrome were the novel risk factors for BSI in pediatric patients after HSCT.

Treatment with mesenchymal stromal cells is a risk factor for pneumonia-related death after allogeneic hematopoietic stem cell transplantation

We performed a retrospective cohort study to find out whether the use of reduced-intensity conditioning (RIC) might reduce the risk of early death from pneumonia. Pneumonia-associated deaths were evaluated in 691 hematopoietic stem cell transplantation (HSCT) patients. The majority had a hematological malignancy (n = 504) and an HLA-matched donor (n = 584). RIC was given to 336 patients and myeloablative conditioning (MAC) to 355. Data concerning radiology, culture and autopsy results were evaluated together with risk factors for death related to pneumonia within or after 100 d after HSCT (early and overall pneumonia). In 60 patients, pneumonia contributed to death (early n = 17). The cumulative incidence of early pneumonia-related death was 2.8% and 2.1% in MAC and RIC patients, respectively. The cumulative incidence of overall pneumonia-related death was 8.2% and 10.5%, respectively. In 40 patients, (67%) an etiology could be established, with 19 patients having proven or probable mold infection. In the multivariate analyses, acute graft-versus-host disease (GVHD) grades II-IV, cytomegalovirus (CMV) infection and having received mesenchymal stromal cells (MSCs) were factors associated with overall pneumonia-related death. Bacteremia and a previous HSCT were associated with early pneumonia-related death. RIC did not reduce the incidence of early death associated with pneumonia. Acute GVHD II-IV, CMV infection and MSC treatment were factors associated with pneumonia-related death. Mold infection was the most common contributor to pneumonia-related death in HSCT patients.

Epidemiology of febrile neutropenia in children with central nervous system tumor: results from a single center prospective study

Data regarding the epidemiology febrile neutropenia during chemotherapy for pediatric central nervous system neoplasia are scarce. Data retrieved from a prospective study performed from January 2002 to December 2004 at G.Gaslini Children Hospital, Genoa, Italy, where analyzed to evaluate proportions, rate for 1000 neutropenic days and etiology of fever in neutropenic children receiving gentle, standard, or peripheral blood stem cell transplant (PBSCT) therapy for central nervous system tumor. During the study duration, 243 periods of neutropenia (granulocyte count <1000/cmm), accounting for 3544 patient-days at risk, were documented in 62 children. A total of 72 febrile episodes were observed in 66 (27%) neutropenic periods, for a rate of 20.31. A primary febrile episode was observed in 10% of neutropenic periods after gentle chemotherapy, in 30% after standard chemotherapy, and in 48% after PBSCT (P<0.0001). The rate of primary febrile episodes was 6.19 after a gentle chemotherapy, 27.02 after standard treatment, and 31.02 after PBSCT (P<0.0001). In a multivariable regression model, the type of chemotherapy (gentle vs. standard and PBSCT) and the thresholds of granulocyte count at neutropenia onset (999-501/cmm and 500-101/cmm vs. ≤100/cmm) were the only factors significantly associated with the development of febrile neutropenia.

Blood stream infections in allogeneic hematopoietic stem cell transplant recipients: reemergence of Gram-negative rods and increasing antibiotic resistance

Blood stream infections (BSI) are a well-known cause of morbidity and mortality in hematopoietic stem cell transplant (HSCT) patients. The aim of this study was to analyze etiology and microbial resistance of BSI in patients undergoing allogeneic HSCT in a single center over a 4-year period (2004-2007). There were 168 episodes of BSI in 132 patients (median 10 days after HSCT) and 182 pathogens were isolated. Gram-positive bacteria (GPB) accounted for 57% of 182 isolates. Gram-negative rods (GNR) for 37% and fungi for 6%. All patients received routine fluoroquinolone prophylaxis. There was a significant decrease in GPB/GNR ratio over time, from 2.4 in 2004 to 1 in 2007 (P = .043). Among GPB, staphylococci decreased from 37 of 68 (64%) in 2004-2005 to 8 of 35 (23%) in 2006-2007 (P < .002). The Enterococcus faecalis/E. faecium ratio decreased from 4.5 in 2004 to 0.33 in 2007 (P = .006), whereas the total number of enterococcal strains per year did not change. The incidence of Escherichia coli among GNR increased from 3 of 15 (20%) in 2004 to 13 of 21 (62%) in 2007 (P = .003). Fluoroquinolone-resistance was common, both among GPB and GNR (81% and 74%, respectively). Mortality rate at 7 days after BSI was 11% (19 of 168), reaching 39% for Pseudomonas aeruginosa BSI (7 of 18). BSI remains a frequent and potentially life-threatening complication of allogeneic HSCT, the causative organism influencing 7- and 30-day mortality rate. BSI etiology may change rapidly, requiring implementation of new empirical-therapy schemes.

Bacteremias in children receiving hemopoietic SCT

The incidence of bacteremia following hemopoietic SCT (HSCT) changes over time from the procedure. The first 30 days have the highest incidence, both in autologous and allogeneic HSCT recipients. In the following periods, bacteremia is a frequent complication in allogeneic HSCT, especially from alternative donors. Gram-positive cocci represent the most frequent cause of single-agent bacteremia. Knowledge of epidemiology (incidence and etiology) of bacteremias following HSCT is pivotal for planning management strategies (prevention, diagnosis and therapy) that must be distinct in the different post-transplant period.

Blood stream infection after hematopoietic stem cell transplantation is associated with increased mortality

Blood stream infection (BSI) is a serious complication of hematopoietic stem cell transplantation (HSCT). The aim of this retrospective cohort analysis was to describe BSI after HSCT, and to assess the predictors and outcomes of BSI after HSCT using multivariable modeling. Of the 243 subjects transplanted, 56% received allogeneic HSCT and 106 (43.6%) developed BSI. Of the 185 isolates, 68% were Gram-positive cocci, 21% were Gram-negative bacilli (GNR) and 11% were fungi. Type of allogeneic HSCT was an independent risk factor for BSI (hazard ratio (HR) 3.26, 95% confidence interval (CI) 1.50, 7.07, P = 0.01), as was the degree of HLA matching (HR 1.84, 95% CI 1.00, 3.37, P = 0.05). BSI was a significant independent predictor of mortality after HSCT (HR 1.79, 95% CI 1.18, 2.73, P = 0.007), after adjusting for acute graft-versus-host disease (GVHD) and allogeneic HSCT (both predicting death < or = 3 months after HSCT). In contrast to the effects of acute GVHD and allogeneic HSCT, the effect of BSI was evident throughout the post-HSCT period. GNR BSI and vancomycin-resistant enterococcal BSI also were significantly associated with death. We concluded that BSI is a common complication of HSCT associated with increased mortality throughout the post-HSCT period.

Comparison of the systemic and pulmonary inflammatory response to endotoxin of neutropenic and non-neutropenic rats

Background

Neutrophil infiltration commonly occurs in acute lung injury and may be partly responsible for the inflammatory response. However, acute lung injury still occurs in the neutropenic host. The objectives of this study are to determine if inflammation and acute lung injury are worse in neutropenic versus the normal host after endotoxemia.

Methods

Rats were divided into four groups: 1) control, 2) neutropenic, 3) endotoxemic and 4) endotoxemic and neutropenic. Tumor necrosis factor (TNF)-α and macrophage inflammatory protein (MIP-2) were measured in the blood, lung lavage and for mRNA in the lung. Arterial blood gases were measured to determine the alveolar-arterial oxygen gradient which reflects on lung injury.

Results

In endotoxemia, the neutropenic rats had lower plasma TNF-α (116 ± 73 vs. 202 ± 31 pg/ml) and higher plasma MIP-2 (26.8 + 11.9 vs. 15.6 + 6.9 ng/ml) when compared to non-neutropenic rats. The endotoxemic, neutropenic rats had worse lung injury than the endotoxemic, non-neutropenic rats as shown by increase in the alveolar-arterial oxygen gradient (24 ± 5 vs. 12 ± 9 torr). However, lavage concentrations of TNF-α and MIP-2 were similar in both groups.

Conclusion

Neutrophils may regulate TNF-α and MIP-2 production in endotoxemia. The elevation in plasma MIP-2 in the endotoxemic, neutropenic rat may be secondary to the lack of a neutrophil response to inhibit production or release of MIP-2. In endotoxemia, the severe lung injury observed in neutropenic rats does not depend on TNF-α or MIP-2 produced in the lung.

Infections in children undergoing allogeneic bone marrow transplantation in India

We studied the clinical profile of infections among 221 pediatric patients who underwent 230 allogeneic transplants between 1986 and June 2004. All patients developed febrile neutropenia. There were 283 documented infections, which included bacterial (36.9%), viral (45.7%), fungal (11.1%) and other infections (6.3%) including tuberculosis. Bacterial and fungal infections were more common in the first 30 days following BMT, while viral infections were more common >30 days after BMT. Bacterial pathogens were predominantly gram-negative organisms (72.7%), when compared with gram-positive organisms (27.3%). Common gram-negative organisms included NFGNB, Pseudomonas, Escherichia coli and Klebsiella while coagulase negative Staphylococci was the main gram-positive organism. Bacteremia (61.2%) was the main source positive cultures and was mainly because of gram-negative organisms (81%), predominantly NFGNB and Pseudomonas. Exactly 103/221(43.7%) transplants had 128 documented viral infections commonly because of Cytomegalovirus, Herpes group of viruses and transfusion related hepatitis. Thirty of 221 (13.5%) of transplants had 30 documented fungal infections with the majority being because of aspergillus (90%). Tuberculosis was seen in 1.7% of transplants while catheter infections were seen in 21 patients (9.1%). Infection related mortality was seen in 12% predominantly because of CMV or fungal infections. A sub group analysis (pre-1998 vs. post-1998) revealed higher incidences of gram-negative infections, bacteremia and bacterial infection related mortality in the pre-1998 era when compared with the recent times. The profile and mortality of infections in this series from India is not significantly different from reports from the West.

[Infectious complications postengrafment in the first year after autologous stem cell transplantation in children]

BACKGROUND

Studies on the infectious complications postengrafment in pediatric stem cell transplantation patients are rare. The aim of this study was to assess the incidence, types, outcome and factors affecting late infections.

PATIENTS AND METHODS

A single-institution retrospective analysis was done of infections recorded in the first year following engrafment in children who underwent autologous stem cell transplantation for solid tumors from January 1991 to December 2000. A systematic antimicrobial chemoprophylaxis of TMP/SMX was administered. Patients who were at high risk for varicella-zona virus infection received prophylactic acyclovir.

RESULTS

Eighty-four assessable patients were enrolled. Fifty-four patients (64%) underwent autologous peripheral blood stem cell transplantation and 30 patients (36%) underwent bone marrow transplantation. Forty-nine episodes of infections were documented in 39 patients (46%) of whom 27 patients (32%) developed infections after the first 100 days post transplantation. Bacterial septicemia occurred in nine patients of whom four patients had a catheter-related septicemia. Twelve patients (14%) developed localized herpes zoster infection. Local fungal infection occurred in five patients. Infection-related death occurred in one patient with non-documented pneumonitis. Univariable analysis showed a correlation between the CD34(+) cell dose <7.5 10(6)/kg and the development of infections (P =0.04). Patients who did not go into remission after transplantation where at high risk for septicemia (P =0.007). Multivariate analysis showed that a history of varicella or pretransplant varicella-zona positivity was the only significant factor for development zoster infection (P =0.01).

CONCLUSION

Our study shows that infections in the first year postengrafment following autologous stem cell transplantation for solid tumors have a good prognosis and that the use of TMP/SMX should be the single systematic antimicrobial prophylaxis. The CD34(+) cell dose seems to play a role in preventing late infections.

Hickman catheter site infections after allogeneic stem cell transplantation: Single-center experience

Hickman catheter site infections are known to increase transplant-related mortality (TRM). A retrospective analysis of 103 patients who received allogeneic SCT (stem cell transplants) was performed to define the incidence and outcomes of Hickman infections. Seventy-six patients received peripheral blood stem cells (PBSCs) (73.8%) and 29 patients (28.2%), nonmyeloablative conditioning. During the median follow-up of 9 months, Hickman infections were observed in 10 patients (9.7%) at a median onset of 32 days posttransplantation (range, 2-102 days). The causative organisms were identified in 5 cases, including Staphylococcus species (n=4) and Pseudomonas aeruginosa (n=1). Six events were successfully resolved with antibiotic treatment, whereas the other 4 events required the removal of the Hickman catheters with subsequent death in 2 cases. The survival duration for the Hickman infection group was shorter than that for the Hickman no infection group (83 days vs 366 days, respectively; P <.001). Myeloid engraftment was delayed in the Hickman infection group (18.0 days vs 15.0 days, respectively; P=.038), plus Hickman infections were more frequent among BMT compared with PBSCT group (22.2% vs 5.3%, respectively, P=.019). Hickman infections were associated with TRM, especially during the first 3 months posttransplantation. As such, the current results emphasize both the importance of Hickman catheter care and the need for surveillance cultures after SCT.

Hickman catheter site infections after allogeneic stem cell transplantation: a single-center experience

Hickman catheter site infections are known to increase transplant-related mortality. A retrospective analysis of 103 patients who received allogeneic stems cell transplants was performed to define the incidence and outcomes of Hickman infections. Seventy-six patients received peripheral blood stem cells (PBSC) (73.8%) and 29 patients (28.2%) nonmyeloablative conditioning. During the median follow-up of 9 months, Hickman infections were observed in 10 patients (9.7%) at a median onset of 32 days posttransplant (range 2 to 102 days). The causative organisms identified in five cases included Staphylococcus species (n = 4) and Pseudomonas aeruginosa (n = 1). Six events successfully resolved with antibiotic treatment, while the other four required the removal of the Hickman catheter with subsequent death in two cases. The survival duration for infected patients was shorter than that for the noninfected group (83 days vs 366 days, P < .001). Myeloid engraftment was delayed in the infected group (18.0 days vs 15.0 days, P = .038) and this complication was more frequently observed among the BMT compared with PBSC group (22.2% vs 5.3%, P = .019). Hickman infections were associated with transplant-related mortality especially during the first 3 months posttransplant. As such, the current results emphasize both the importance of Hickman catheter care and the need for surveillance cultures after stem cell transplantation.

Immune reconstitution, infectious complications and post transplant supportive care measures after autologous blood and marrow transplantation in children

We retrospectively analyzed data on T- and B-cell reconstitution and infectious complications in 58 children undergoing ABMT, in order to evaluate post-transplant supportive care measures used during the study period. Normalization of T-cell number and lymphocyte proliferative responses to phytohemagglutinin (PHA) and alloantigen (MLC) occurred in two-thirds of children by 6 months post transplant. Normal IgM levels developed in 75% of children by 6 months post transplant. A total of 34 children (59%) developed 39 episodes of infection between neutrophil engraftment and 1 year post transplant. The most common infections included bacteremia, varicella-zoster virus infection and pneumonia, which represented 46, 23 and 9% of infections, respectively. All patients with bacteremia had a central venous catheter in place at the time of infection. Most infections (77%) developed by 6 months post transplant. In this small patient cohort, time to normalization of tests of T- and B-cell function was not significantly different between patients with and without infection. Earlier removal of an indwelling central venous catheter may decrease the risk of bacteremia post transplant. Post-transplant supportive care measures may be discontinued at 6 months post ABMT in most children, as the risk of infection decreases after that time.

Neutrophil defense in patients undergoing bone marrow transplantation: bactericidal/permeability-increasing protein (BPI) and defensins in graft-derived neutrophils

BACKGROUND

Even after neutrophil counts return to near normal levels, patients undergoing myeloablative chemotherapy and bone marrow transplantation (BMT) are at risk for invasive bacterial infections, raising the possibility that their neutrophil function might be impaired. To assess potential qualitative defects in neutrophil function in patients undergoing BMT, we measured neutrophil content of the antimicrobial (poly)peptides BPI and defensins.

METHODS

Neutrophil extracts were analyzed for content of BPI by Western blotting and ELISA and for defensin peptides by acid-urea polyacrylamide gel electrophoresis (PAGE). Antibacterial activity of neutrophil extracts was measured against Escherichia coli K1/r, a clinical isolate sensitive to synergistic killing by BPI and defensins.

RESULTS

Neutrophil extract BPI content on post-BMT days +20, +30, and +100 (169+/-35, 232+/-57, and 160+/-55 ng per 106 neutrophils, respectively) was similar to the neutrophil BPI content of normal controls (163+/-35 ng per 106 neutrophils). Neutrophil defensin content also did not vary during this time-span. Activity of neutrophil extracts against E. coli K1/r did not differ between BMT patients and controls.

CONCLUSION

At post-BMT days +20 to +100, neutrophils derived from engrafted marrow contain normal quantities of BPI and defensins. Any deficiencies of neutrophil function during this phase are not due to inadequate expression of these antimicrobial (poly)peptides but could reflect abnormalities in other aspects of neutrophil function.

Incidence of septicaemias and invasive mycoses in children undergoing treatment for solid tumours: a 12-year experience at a single Italian institution

We carried out a retrospective study on the infection rate--in episodes per 100 person months at risk (p/m/r)--of septicaemia and invasive mycoses in children with solid tumours treated at a single institution between 1985 and 1996. Among 982 patients, accounting for 8108 p/m/r, 257 infectious episodes were documented, for an infection rate of 3.2. The infection rate for "intensive" treatment was greater than that for "less intensive" treatments, 3.7 compared with 0.5, respectively; P<0.001. 58% of infectious episodes were associated with neutropenia, 22% were megatherapy-related, and 39% were related to central venous catheter (CVC), while in 13% of the episodes no risk factor was identified. Of the episodes, single organism Gram-positive bacteraemias accounted for 62%, single organism Gram-negative for 23%, multiple organism bacteraemias for 7%, invasive mycoses for 4%, and isolated fungaemias for 4%. The infection rate for Gram-positive organisms decreased significantly over time (-5.9% per year; P<0.01), but increased for the Gram-negative organisms (+3.4% per year; P=0.4). This study demonstrates that the risk of bacteraemia increases in parallel with the treatment intensity, and that a considerable number of children with solid tumours develop bacteraemia in the absence of an identifiable risk factor.

Fever and neutropenia in pediatric hematopoietic stem cell transplant patients

The objective of this study was to identify patterns of fever and neutropenia in pediatric patients undergoing initial hospitalization for hematopoietic stem cell transplantation. A retrospective review of 75 HSCTs over a 4-year period at a single institution was performed, of which 68% were allogeneic and 32% were autologous. Stem cell sources included bone marrow (29%), PBSC (52%) and umbilical cord blood (16%). Fever occurred in 74 (98%) of the episodes. Unexplained fever (FUO) occurred in 43%. Bacteremia without an anatomic focus occurred in 29%, while CVC associated infections occurred in 17%. In 49% of transplants at least one blood culture was positive. The incidence of bacteremia was higher in allogeneic HSCTs (58%) than in autologous transplants (29%). Gram-positive bacteria accounted for 71% of the isolates. Lower rates of bacteremia were observed in patients receiving oral fluoroquinolone prophylaxis. The median duration of fever was 12.5 days and time to engraftment 14 days. Regression analysis demonstrated that duration of fever was strongly associated with time to engraftment, and that time to engraftment was associated with source of cells and number of CD34+ cells/kg administered. Recipients of autologous PBSC had the shortest durations of fever and time to engraftment, while recipients of allogeneic umbilical cord blood had the longest. Bone Marrow Transplantation (2000) 25, 59-65.