Using Teamwork to Bridge the Adolescent and Young Adult Gap

PURPOSE

Individuals diagnosed with cancer age between 15 and 39 years (adolescents and young adults [AYAs]) have not seen improvement in survival compared with children or older adults; clinical trial accrual correlates with survival. Unique unmet needs among AYAs related to psychosocial support and fertility preservation (FP) are associated with health-related quality of life.

METHODS

We enhanced existing structures and leveraged faculty/staff across pediatric/adult oncology to create novel teams focused on AYA (age 15-39 years) care at a single center, with minimal dedicated staff and no change to revenue streams. We aimed to influence domains shown to drive survival and health-related quality of life: clinical trial enrollment, physician/staff collaboration, psychosocial support, and FP. We captured metrics 3 months after patients presented to the institution and compared them before/after Program implementation using descriptive statistics.

RESULTS

Among 139 AYAs (age 15-39 years) from the pre-Program era (January 2016-February 2019: adult, n = 79; pediatric, n = 60), and 279 from the post-Program era (February 2019-March 2022: adult, n = 215; pediatric, n = 64), there was no change in clinical trial enrollment(P ≥ .3), whereas there was an increase in the proportion of AYAs referred for supportive care and psychology (pediatric: P ≤ .02; adult: P ≤ .001); whose oncologists discussed FP (pediatric: 15% v 52%, P < .0001; adult: 37% v 50%, P = .0004); and undergoing FP consults (pediatric: 8% v39%, P < .0001; adult 23% v 38%, P = .02).

CONCLUSION

This team-based framework has effected change in most targeted domains. To affect all domains and design optimal interventions, it is crucial to understand patient-level and facility-level barriers/facilitators to FP and clinical trial enrollment.

The Changes in Epidemiology of Imipenem-Resistant Acinetobacter baumannii Bacteremia in a Pediatric Intensive Care Unit for 17 Years

BACKGROUND

Acinetobacter baumannii infections cause high morbidity and mortality in intensive care unit (ICU) patients. However, there are limited data on the changes of long-term epidemiology of imipenem resistance in A. baumannii bacteremia among pediatric ICU (PICU) patients.

METHODS

A retrospective review was performed on patients with A. baumannii bacteremia in PICU of a tertiary teaching hospital from 2000 to 2016. Antimicrobial susceptibility tests, multilocus sequence typing (MLST), and polymerase chain reaction for antimicrobial resistance genes were performed for available isolates.

RESULTS

A. baumannii bacteremia occurred in 27 patients; imipenem-sensitive A. baumannii (ISAB, n = 10, 37%) and imipenem-resistant A. baumannii (IRAB, n = 17, 63%). There was a clear shift in the antibiogram of A. baumannii during the study period. From 2000 to 2003, all isolates were ISAB (n = 6). From 2005 to 2008, both IRAB (n = 5) and ISAB (n = 4) were isolated. However, from 2009, all isolates were IRAB (n = 12). Ten isolates were available for additional test and confirmed as IRAB. MLST analysis showed that among 10 isolates, sequence type 138 was predominant (n = 7). All 10 isolates were positive for OXA-23-like and OXA-51-like carbapenemase. Of 27 bacteremia patients, 11 were male (41%), the median age at bacteremia onset was 5.2 years (range, 0-18.6 years). In 33% (9/27) of patients, A. baumannii was isolated from tracheal aspirate prior to development of bacteremia (median, 8 days; range, 5-124 days). The overall case-fatality rate was 63% (17/27) within 28 days. There was no statistical difference in the case fatality rate between ISAB and IRAB groups (50% vs. 71%; P = 0.422).

CONCLUSION

IRAB bacteremia causes serious threat in patients in PICU. Proactive infection control measures and antimicrobial stewardship are crucial for managing IRAB infection in PICU.

581. The Epidemiology of Imipenem-Resistant Acinetobacter baumannii Bacteremia in a Pediatric Intensive Care Unit and Carbapenem Use

Background

Acinetobacter baumannii (AB) infections cause high mortality and morbidity in intensive care unit patients. There are limited data on the epidemiology of imipenem-resistant A. baumannii (IRAB) amongst pediatric ICU patients.

Methods

A retrospective chart review was performed in patients with AB bacteremia in a pediatric intensive care unit at a tertiary teaching hospital from January 2000 to December 2016. Antimicrobial susceptibility tests, multilocus sequence typing (MLST) and PCR for antimicrobial resistance genes were performed for stored isolates. In addition, antibiotic prescription days of therapy (DOT per 1,000 patient-days) of the pediatric department from January 2001 to December 2016 was analyzed.

Results

Bacteremia episodes occurred in 27 patients. Male patients were 11 (41%) and the median age at the onset of bacteremia was 5.2 years (range, 0–18.6 years). There was a clear shift in antibiogram of AB during the study period. From 2000 to 2003, all isolates were imipenem-sensitive (ISAB, N = 6). From 2005 to 2008, both IRAB (N = 5) and ISAB (N = 4) were isolated. However, since 2009, all the AB isolates were IRAB (N = 12). In 33% (9/27) of patients, first AB was isolated from tracheal aspirate and patients developed bacteremia later (median duration from AB positive tracheal culture to AB positive blood culture, 8 days [range 5–124]). The overall mortality of patients with AB bacteremia was 59.3% (16/27) within 28 days. There was no statistical difference in mortality between ISAB and IRAB groups (50% vs. 71%; P = 0.42). From MLST analysis of 10 available isolates, sequence type 138 was predominant (N = 7). All 10 isolates were positive for OXA-23-like and OXA-51-like carbapenemase. In 2001, carbapenem DOT per 1,000 patient-days was 15.3 and later strikingly raised to 82.5 in 2009 when all the isolates were imipenem resistant. After this IRAB outbreak in PICU, proactive infection control and antimicrobial stewardship were reinforced among multidisciplinary teams in PICU. IRAB outbreak was terminated and carbapenem DOT per 1,000 patient-days was decreased to 51.7 in 2016.

Conclusion

IRAB bacteremia causes serious threat in high-risk pediatric patients in PICU. Proactive infection control measures and antimicrobial stewardship are crucial to manage serious IRAB infection in PICU.

Disclosures

All authors: No reported disclosures.

Reduced Dentin Matrix Protein Expression in Camurati-Engelmann Disease Transgenic Mouse Model

Overexpression of transforming growth factor-β1 (TGF-β1) has been shown to lead to mineralization defects in both the enamel and dentin layers of teeth. A TGFB1 point mutation (H222D), derived from published cases of Camurati-Engelmann disease (CED), has been shown to constitutively activate TGF-β1, leading to excess bone matrix production. Although CED has been well documented in clinical case reports, there are no published studies on the effect of CED on the dentition. The objective of this study was to determine the dental manifestations of hyperactivated TGF-β1 signaling using an established mouse model of CED-derived TGF-β1 mutation. Murine dental tissues were studied via radiography, micro-CT, immunohistochemistry, and qRT-PCR. Results showed that initial decreased dental mineralized tissue density is resolved. Proliferation assays of incisor pulp and alveolar bone cell cultures revealed that cells from transgenic animals displayed a reduced rate of growth compared to alveolar bone cultures from wild-type mice. TGF-β family gene expression analysis indicated significant fold changes in the expression of Alpl, Bmp2-5, Col-1, -2, -4, and -6, Fgf, Mmp, Runx2, Tgfb3, Tfgbr3, and Vdr genes. Assessment of SIBLINGs revealed downregulation of Ibsp, Dmp1, Dspp, Mepe, and Spp1, as well as reduced staining for BMP-2 and VDR in mesenchymal-derived pulp tissue in CED animals. Treatment of dental pulp cells with recombinant human TGF-β1 resulted in increased SIBLING gene expression.

CONCLUSIONS

Our results provide in vivo evidence suggesting that TFG-β1 mediates expression of important dentin extracellular matrix components secreted by dental pulp, and when unbalanced, may contribute to abnormal dentin disorders.

Pneumococcal surface protein A inhibits complement deposition on the pneumococcal surface by competing with the binding of C-reactive protein to cell-surface phosphocholine

In the presence of normal serum, complement component C3 is deposited on pneumococci primarily via the classical pathway. Pneumococcal surface protein A (PspA), a major virulence factor of pneumococci, effectively inhibits C3 deposition. PspA's C terminus has a choline-binding domain that anchors PspA to the phosphocholine (PC) moieties on the pneumococcal surface. C-reactive protein (CRP), another important host defense molecule, also binds to PC, and CRP binding to pneumococci enhances complement C3 deposition through the classical pathway. Using flow cytometry of PspA(+) and PspA(-) strains, we observed that the absence of PspA led to exposure of PC, enhanced the surface binding of CRP, and increased the deposition of C3. Moreover, when the PspA(-) mutant was incubated with a pneumococcal eluate containing native PspA, there was decreased deposition of CRP and C3 on the pneumococcal surface compared with incubation with an eluate from a PspA(-) strain. This inhibition was not observed when a recombinant PspA fragment, which lacks the choline-binding region of PspA, was added to the PspA(-) mutant. Also, there was much greater C3 deposition onto the PspA(-) pneumococcus when exposed to normal mouse serum from wild-type mice as compared with that from CRP knockout mice. Furthermore, when CRP knockout mouse serum was replenished with CRP, there was a dose-dependent increase in C3 deposition. The combined data reveal a novel mechanism of complement inhibition by a bacterial protein: inhibition of CRP surface binding and, thus, diminution of CRP-mediated complement deposition.