Contributions
Abstract: PB2461
Type: Publication Only
Background
Infections are the most common complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). They are associated with significant morbidity and mortality. In the early post-engraftment bacterial infections and reactivation of latent viruses is frequently seen due to immunosuppressive therapy. There is lack of literature on infection incidence and description of causative pathogens which would be of interest towards any future studies looking at prophylaxis strategies.
Aims
To identify the rates of bacterial and viral infections in allo-HSCT recipients during the first 180 days post-neutrophil engraftment. To compare the infection rates between matched unrelated donors (MUD) and sibling allo-HSCTs.To compare infection rates between myeloablative and reduced intensity conditioning (RIC) allo-HSCTs. To describe the common bacterial and viral organisms causing infection.
Methods
Data was collected retrospectively for all patients that underwent an allo-HSCT from January 2015 to December 2017. All positive blood cultures and viral specimens for each patient were identified for the time period specified using the laboratory database systems. Data was analysed using Prism (Graphpad). Student’s t test was used for comparing medians and chi squared for proportions. A p value <0.5 was considered significant.
Results
113 patients received an allo-HSCT during the study period. The median age was 54 (SD 15 years, range 19-72). The majority of donors were matched unrelated donors (MUDs), 64% , with 29% of allograft from sibling donors, 5% haploidentical and 2% with cord blood stem cells. Myeloablative conditioning was used in 19% of allografts whereas (RIC) was used in 81% of transplants. There was no difference in the number of episodes of viral infection in MUD allografts compared to sibling allografts (MUD median 2, SD 1.4, sibling median 2, SD 1.6.) (p > 0.05, unpaired t test). The commonest viral infection was EBV, occurring in 55% of patients overall. EBV infection was significantly more common in sibling allografts at 78% than MUD allografts at 47% (p<0.05). Infections with respiratory viruses were significantly more common following myeloablative conditioning, with adenovirus and respiratory syncytial virus both seen in 23 % of myeloablative allografts, compared to 5% and 3% respectively of RIC allografts (p <0.05).Data on p 54% of patients had at least one positive blood culture. There was no difference in the proportion of patients with a positive blood culture in MUD allografts compared to sibling allografts (MUD 50%, sibling 55%) (p>0.05) The organisms isolated were diverse, with a total of 25 different genera/species isolated. The commonest were coagulase negative staphylococci or mixed coagulase negative staphylococci 49% Pseudomonas sp in 14%, Escherichia coli in 8% and Klebsiella sp and Enterococcus sp each in 7%.
Conclusion
We present a comprehensive description of the types and frequencies of bacterial and viral infections in allo-HSCT recipients during the first 180 days post neutrophil engraftment. There are statistically significant differences in patterns of viral reactivation according to donor and conditioning regimen, which may have implications for surveillance, prophylaxis and empirical treatment in these patient groups.
Session topic: 23. Stem cell transplantation - Clinical
Keyword(s): Allogeneic bone marrow transplant
Abstract: PB2461
Type: Publication Only
Background
Infections are the most common complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). They are associated with significant morbidity and mortality. In the early post-engraftment bacterial infections and reactivation of latent viruses is frequently seen due to immunosuppressive therapy. There is lack of literature on infection incidence and description of causative pathogens which would be of interest towards any future studies looking at prophylaxis strategies.
Aims
To identify the rates of bacterial and viral infections in allo-HSCT recipients during the first 180 days post-neutrophil engraftment. To compare the infection rates between matched unrelated donors (MUD) and sibling allo-HSCTs.To compare infection rates between myeloablative and reduced intensity conditioning (RIC) allo-HSCTs. To describe the common bacterial and viral organisms causing infection.
Methods
Data was collected retrospectively for all patients that underwent an allo-HSCT from January 2015 to December 2017. All positive blood cultures and viral specimens for each patient were identified for the time period specified using the laboratory database systems. Data was analysed using Prism (Graphpad). Student’s t test was used for comparing medians and chi squared for proportions. A p value <0.5 was considered significant.
Results
113 patients received an allo-HSCT during the study period. The median age was 54 (SD 15 years, range 19-72). The majority of donors were matched unrelated donors (MUDs), 64% , with 29% of allograft from sibling donors, 5% haploidentical and 2% with cord blood stem cells. Myeloablative conditioning was used in 19% of allografts whereas (RIC) was used in 81% of transplants. There was no difference in the number of episodes of viral infection in MUD allografts compared to sibling allografts (MUD median 2, SD 1.4, sibling median 2, SD 1.6.) (p > 0.05, unpaired t test). The commonest viral infection was EBV, occurring in 55% of patients overall. EBV infection was significantly more common in sibling allografts at 78% than MUD allografts at 47% (p<0.05). Infections with respiratory viruses were significantly more common following myeloablative conditioning, with adenovirus and respiratory syncytial virus both seen in 23 % of myeloablative allografts, compared to 5% and 3% respectively of RIC allografts (p <0.05).Data on p 54% of patients had at least one positive blood culture. There was no difference in the proportion of patients with a positive blood culture in MUD allografts compared to sibling allografts (MUD 50%, sibling 55%) (p>0.05) The organisms isolated were diverse, with a total of 25 different genera/species isolated. The commonest were coagulase negative staphylococci or mixed coagulase negative staphylococci 49% Pseudomonas sp in 14%, Escherichia coli in 8% and Klebsiella sp and Enterococcus sp each in 7%.
Conclusion
We present a comprehensive description of the types and frequencies of bacterial and viral infections in allo-HSCT recipients during the first 180 days post neutrophil engraftment. There are statistically significant differences in patterns of viral reactivation according to donor and conditioning regimen, which may have implications for surveillance, prophylaxis and empirical treatment in these patient groups.
Session topic: 23. Stem cell transplantation - Clinical
Keyword(s): Allogeneic bone marrow transplant