α4β7 Integrin expression and blockade in pediatric and young adult gastrointestinal graft-versus-host disease

BACKGROUND

We hypothesized that α4β7 integrin expression on effector memory T cells (TEMs) would be elevated in pediatric hematopoietic stem cell transplant (HSCT) patients before and at diagnosis of acute gastrointestinal graft-versus-host disease (GI GVHD) symptoms compared to patients without GVHD, and that clinical blockade of α4β7 integrin with vedolizumab would be effective in pediatric GI GVHD.

METHODS

We analyzed surface expression of α4β7 integrin on T cells from 48 pediatric allogeneic HSCT recipients from our biorepository with known clinical outcomes as follows: acute GI GVHD (n = 22), isolated skin GVHD (n = 12), and no GVHD (n = 14). T-cell analyses were performed 1 week before and at GVHD diagnosis in patients with GVHD, and day +30 after HSCT in patients without GVHD. We describe clinical outcomes of seven additional patients, different from above-described 48 patients, who received vedolizumab (anti-α4β7 integrin antibody) for the treatment of steroid-refractory acute GI GVHD.

RESULTS

Expression of α4β7 integrin on CD8+ TEMs was upregulated in patients with GI GVHD compared to the no GI GVHD (skin GVHD + no GVHD) group 1 week prior to clinical symptoms (p = .02) and at acute GI GVHD diagnosis (p = .05). Four of seven treated patients with clinical steroid-refractory acute GI GVHD were evaluable for response to vedolizumab. One patient had a complete response at day +28, while two had a partial response, and one had no response. No adverse effects directly attributable to vedolizumab were observed.

CONCLUSION

Our data suggest a rationale for the blockade of α4β7 integrin for acute GI GVHD management in children.

Presentation acuity, induction mortality, and resource utilization in infants with acute leukemia

BACKGROUND

Treatment of infants with acute leukemia remains challenging, especially for acute lymphocytic leukemia (ALL). Infants have shown markedly higher rates of induction mortality compared with noninfants. There are limited data on presentation acuity and supportive care utilization in this age group.

METHODS

In retrospective analyses of patients treated for new onset ALL or acute myeloid leukemia (AML) at pediatric hospitals contributing to the Pediatric Health Information System, we compared presentation acuity, induction mortality, and resource utilization in infants relative to noninfants less than 10 years at diagnosis.

RESULTS

Analyses included 10 359 children with ALL (405 infants, 9954 noninfants) and 871 AML (189 infants, 682 noninfants). Infants were more likely to present with multisystem organ failure compared to noninfants for both ALL (12% and 1%, PR = 10.8, 95% CI: 7.4, 15.7) and AML (6% vs. 3%; PR = 2.0, 95% CI: 1.0, 3.7). Infants with ALL had higher induction mortality compared to noninfants, even after accounting for differences in anthracycline exposure and presentation acuity (2.7% vs. 0.5%, HR = 2.1, 95% CI: 1.0, 4.8). Conversely, infants and noninfants with AML had similar rates of induction mortality (3.2% vs. 2.1%, HR = 1.2, 95% CI: 0.3, 3.9), which were comparable to rates among infants with ALL. Infants with ALL and AML had greater requirements for blood products, diuretics, supplemental oxygen, and ventilation during induction relative to noninfants.

CONCLUSIONS

Infants with leukemia present with higher acuity compared with noninfants. Induction mortality and supportive care requirements for infants with ALL were similar to all children with AML, and significantly higher than those for noninfants with ALL.

Forced deflation pulmonary function test: a novel method to evaluate lung function in infants and young children

We describe the safety and feasibility of a forced deflation pulmonary function test (dPFT) in infants and young children. Fifty-two dPFT studies were performed in 26 patients (median age, 1.4 years). Forced vital capacity (FVC) and forced expiratory flow (FEF₇₅ ) were normal in all except one case, but respiratory system compliance (Crs) was reduced in 24% patients. There were no significant differences in pre-blood and marrow transplantation FVC, FEF₇₅ , and Crs between those patients who did and those who did not have posttransplant pulmonary complications. A larger study is needed to determine the prevalence and significance of PFT abnormalities in this age group.

Using electronic medical record data to report laboratory adverse events

Despite the importance of adverse event (AE) reporting, AEs are under-reported on clinical trials. We hypothesized that electronic medical record (EMR) data can ascertain laboratory-based AEs more accurately than those ascertained manually. EMR data on 12 AEs for patients enrolled on two Children's Oncology Group (COG) trials at one institution were extracted, processed and graded. When compared to gold standard chart data, COG AE report sensitivity and positive predictive values (PPV) were 0-21·1% and 20-100%, respectively. EMR sensitivity and PPV were >98·2% for all AEs. These results demonstrate that EMR-based AE ascertainment and grading substantially improves laboratory AE reporting accuracy.