Assessment on the use of allopurinol to improve safety and efficacy of mercaptopurine in pediatric patients with Acute Lymphoblastic Leukemia and Lymphoma during maintenance therapy

BACKGROUND

Mercaptopurine is an important component of acute lymphoblastic leukemia (ALL) and lymphoma (LLy) maintenance therapy. The 6-thioguanine nucleosides (6-TGN) are believed to be the primary contributor to myelosuppression and immunosuppressive effects, while 6-methylmercaptopurine (6-MMPN) is believed to be responsible for several toxicities including hepatotoxicity, pancreatitis, and hypoglycemia. Previous reports suggest the addition of allopurinol may reduce these toxicities.

AIMS

To assess the use of allopurinol to improve both safety and efficacy of mercaptopurine in pediatric patients with ALL and LLy during maintenance therapy. Secondary objectives included evaluating patient tolerability and skewed metabolism. In addition, we also analyzed mercaptopurine daily dose reduction upon allopurinol initiation.

METHODS AND RESULTS

The primary endpoint was time within goal ANC prior to and after initiation of allopurinol. Secondary endpoints included; improvement in selective toxicities (hepatotoxicity, pancreatitis, and hypoglycemia) and 6-MMPN to 6-TGN ratio prior to and after allopurinol initiation. In addition, an exploratory endpoint assessing mercaptopurine daily dose reduction prior to and after allopurinol initiation was included. Sixteen patients met inclusion criteria and 15 (94%) of which were included in this study. Median percent of maintenance days within goal ANC prior to and after initiation of allopurinol was 27.8 (IQR 22.6-44.9) and 41.6 (IQR 20.2-58.2) respectively. All patients experienced selective toxicities; 15 (100%) hepatotoxicity, 1 (7%) pancreatitis, and 3 (20%) hypoglycemia. Improvement of toxicities was seen in 13/15 (87%), 1/1 (100%), and 2/3 (67%) respectively. Average 6-MMPN:6-TGN ratio prior to allopurinol initiation was 304:1 and after, allopurinol initiation improved to 15:1, resulting in a 95% reduction. Average mercaptopurine dose prior to and after allopurinol initiation decreased by about 56% (63 to 28 mg/m2 /day).

CONCLUSION

Results suggest that the use of allopurinol in pediatric patients with ALL and LLy receiving mercaptopurine during maintenance therapy is both safe and effective.

Comparison of whole blood cytokine immunoassays for rapid, functional immune phenotyping in critically ill patients with sepsis

BACKGROUND

Sepsis is characterized by highly heterogeneous immune responses associated with a spectrum of disease severity. Methods that rapidly and sensitively profile these immune responses can potentially personalize immune-adjuvant therapies for sepsis. We hypothesized that the ELLA microfluidic approach to measure cytokine production from the whole blood of septic and critically ill patients would deliver faster, more precise results than the existing optic-driven ELISpot quantification. We tested our hypothesis by measuring ex vivo-stimulated production of TNF and IFNγ in critically ill and septic patients (n = 22), critically ill and non-septic patients (n = 10), and healthy volunteers (n = 10) through both ELLA and ELISpot immunoassays. Blood samples were subjected to one of three stimulants for 4 h or 18 h durations during days 1, 7-10, and 14 of critical illness. Stimulants for lymphocytes included anti-CD3/anti-CD28 and phorbol 12-myristate 13-acetate (PMA), whereas LPS was used for monocytes. Stimulated TNF and IFNγ concentrations were then associated with 30-day mortality.

RESULTS

Both ELISpot and ELLA immunoassays showed substantial agreement in TNF concentrations post 4 h and 18 h LPS stimulation, with concordance correlation coefficients at 0.62 and 0.60, respectively. ELLA had a broad dynamic measurement range and provided accurate TNF and IFNγ readings at both minimal and elevated cytokine concentrations (with mean coefficients of variation between triplicate readings at 2.1 ± 1.4% and 4.9 ± 7.2%, respectively). However, there was no association between the ELLA-determined cytokine concentrations on the first day of critical illness and 30-day mortality rate. In contrast, using the ELISpot for cytokine quantification revealed that non-survivors had reduced baseline TNF levels at 18 h, decreased LPS-induced TNF levels at 18 h, and diminished TNF levels post 4 h/18 h anti-CD3/28 stimulation.

CONCLUSIONS

Our study affirms the feasibility of obtaining dependable immune phenotyping data within 6 h of blood collection from critically ill patients, both septic and non-septic, using the ELLA immunoassay. Both ELLA and ELISpot can offer valuable insights into prognosis, therapeutic strategies, and the underlying mechanisms of sepsis development.

The Association between Infant Colic and the Multi-Omic Composition of Human Milk

Infant colic is a common condition with unclear biologic underpinnings and limited treatment options. We hypothesized that complex molecular networks within human milk (i.e., microbes, micro-ribonucleic acids (miRNAs), cytokines) would contribute to colic risk, while controlling for medical, social, and nutritional variables. This hypothesis was tested in a cohort of 182 breastfed infants, assessed with a modified Infant Colic Scale at 1 month. RNA sequencing was used to interrogate microbial and miRNA features. Luminex assays were used to measure growth factors and cytokines. Milk from mothers of infants with colic (n = 28) displayed higher levels of Staphylococcus (adj. p = 0.038, d = 0.30), miR-224-3p (adj. p = 0.023, d = 0.33), miR-125b-5p (adj. p = 0.028, d = 0.29), let-7a-5p (adj. p = 0.028, d = 0.27), and miR-205-5p (adj. p = 0.029, d = 0.26) compared to milk from non-colic mother-infant dyads (n = 154). Colic symptom severity was directly associated with milk hepatocyte growth factor levels (R = 0.21, p = 0.025). A regression model involving let-7a-5p, miR-29a-3p, and Lactobacillus accurately modeled colic risk (X² = 16.7, p = 0.001). Molecular factors within human milk may impact colic risk, and provide support for a dysbiotic/inflammatory model of colic pathophysiology.

Understanding immunological origins of atopic dermatitis through multi-omic analysis

BACKGROUND

The pathophysiology of atopic dermatitis (AD) is multifactorial, impacted by individual medical, demographic, environmental, and immunologic factors. This study used multi-omic analyses to assess how host and microbial factors could contribute to infant AD development.

METHODS

This longitudinal cohort study included 129 term infants, identified as AD (n = 37) or non-AD (n = 92) using the Infant Feeding Practices-II survey and review of medical records. Standardized surveys were used to assess medical and demographic traits (gestational age, sex, race, maternal AD, and atopy family history), and environmental exposures (delivery method, maternal tobacco use, pets, breastfeeding duration, and timing of solid food introduction). Saliva was collected at 6 months for multi-omic assessment of cytokines, microRNAs, mRNAs, and the microbiome. The contribution of each factor to AD status was assessed with logistic regression.

RESULTS

Medical, demographic, and environmental factors did not differ between AD and non-AD infants. Five "omic" factors (IL-8/IL-6, miR-375-3p, miR-21-5p, bacterial diversity, and Proteobacteria) differed between groups (p < .05). The severity of AD was positively associated with levels of miR-375-3p (R = .17, p = .049) and Proteobacteria (R = .22, p = .011), and negatively associated with levels of miR-21-5p (R = .20, p = .022). Multi-omic features accounted for 17% of variance between groups, significantly improving an AD risk model employing medical, demographic, and environmental factors (X²  = 32.47, p = .006).

CONCLUSION

Interactions between the microbiome and host signaling may predispose certain infants to AD by promoting a pro-inflammatory environment.

Abstract P5-13-10: Elevated plasma IL-8 predicts for reduced outcomes in CCTG MA.38, a phase 2 randomized trial of palbociclib in ER+/HER2- metastatic breast cancer patients

Background: CCTG MA38 (NCT02630693) was a randomized phase II clinical trial that evaluated the efficacy of 2 dose schedules of palbociclib [100mg PO on continuous daily dose (CDD)] compared to 125mg PO daily for 3 weeks on/1 week off (STD) along with physician-choice of endocrine therapy in patients with ER+, HER- metastatic breast cancer (MBC) in the second-line setting. The final analysis indicated that palbociclib had comparable efficacy, safety and QOL for both treatment arms (SABCS 2018, abstr PD1-10). Our lab has reported that IL-8 was highly expressed by primary human breast cancers, and that higher pretreatment plasma IL-8 was significantly correlated with elevated bone resorption in HR+MBC patients (Kamalakar A et al. Bone 61:176-85, 2014). Most recently, our lab has reported that elevated serum IL-8 predicts for significantly reduced OS in 3 large metastatic cohorts of pancreatic (ASCO 2019, abstr 4131), prostate (ASCO 2020, abstr e17565) and breast cancer patients (ASCO 2020, abstr 1067). In this retrospective study, we investigated the prognostic value of pretreatment plasma IL-8 in CCTG MA38. Methods: 123 patients enrolled in MA38 were analyzed in this retrospective biomarker study. Serum IL-8 levels were measured using the ELLA immunoassay platform (ProteinSimple, San Jose, CA). Kaplan-Meier analysis and log-rank test were used to correlate plasma IL-8 levels with OS and progression-free survival (PFS). Results: In the total study cohort, pretreatment plasma IL-8 concentration had a median of 11.10 pg/ml, and 25% and 75% interquartiles of 7.36 and 15.00 pg/ml, respectively. In univariate analysis higher plasma IL-8 was a significant adverse biomarker for reduced PFS as a continuous variable (p = 0.01), at the median cutpoint (HR= 1.55, p=0.042), and in quartile cutpoints (HR=2.28, p=0.03, Q4 vs Q1). For OS, higher plasma IL-8 also trended significant for reduced OS at the median cutpoint (HR= 1.66, p=0.10). In multivariate analysis, higher plasma IL-8 also trended significant for reduced PFS (HR= 1.47, p=0.094). Conclusions: In the CCTG MA.38 trial, higher pre-treatment plasma IL-8 level was associated with reduced PFS, and is therefore an adverse prognostic biomarker for reduced outcome to the CDK 4/6 inhibitor palbociclib. Anti-IL-8 therapy combined with CDK 4/6 inhibitors should be evaluated in future trials to improve outcome in patients with higher circulating IL-8.

Citation Format: Hyma V Polimera, Dhirisha Bhatt, Lois E Shepherd, Karen Gelmon, Anil A Joy, Wendy R Parulekar, Monika Joshi, Suhail M Ali, Kim Leitzel, Cristina Truica, Monali Vasekar, Joseph J Drabick, Harry Menon, Neal Shah, Ashok Maddukuri, Prashanth Moku, E. Scott Halstead, Daniel McKeone, Todd M Umstead, BE Chen, Allan Lipton. Elevated plasma IL-8 predicts for reduced outcomes in CCTG MA.38, a phase 2 randomized trial of palbociclib in ER+/HER2- metastatic breast cancer patients [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-13-10.

PICU Passport: Pilot study of a handheld resident curriculum

BACKGROUND

To explore the impact of an educational tool designed to streamline resident learning during their pediatric intensive care (PICU) rotations.

METHODS

Topics and procedures were chosen for inclusion based on national requirements for pediatric residents. Residents received a PICU Passport at the beginning of their rotations. PICU faculty were provided learning objectives for each topic. Residents and faculty were surveyed before and after starting use of the Passport.

RESULTS

Twenty-two residents pre-Passport and 38 residents post-Passport were compared. Residents were more satisfied with their educational experiences (27 % vs. 79 %; P < 0.001), more likely to report faculty targeted teaching towards knowledge gaps (5 % vs. 63 %; P < 0.001) and felt more empowered to ask faculty to discuss specific topics (27 % vs. 76 %; P = 0.002). The median number of teaching sessions increased from 3 to 10 (Z = 4.2; P < 0.001). Most residents (73 %) felt the Passport helped them keep track of their learning and identify gaps in their knowledge.

CONCLUSIONS

The PICU Passport helps residents keep track of their learning and identify gaps in their knowledge. Passport use increases resident satisfaction with education during their PICU rotation and empowers residents to ask PICU faculty to address specific knowledge gaps.

Plasma IL-8 and PD-L1 and overall survival in metastatic castration-resistant prostate cancer patients (mCRPC)

e17565

Background: We previously reported the significant prognostic and predictive utility of pretreatment serum PD-L1 in the CCTG MA.31 breast cancer serum bank (SABCS 2018, abstr PD3-10). IL-8 (CXCL8) is a pro-inflammatory cytokine that binds to CXCR1 and CXCR2 and promotes tumor immune escape and progression. High serum IL-8 levels are associated with poor prognosis in many cancers, and have recently been reported to predict for reduced overall survival (OS) to nivolumab in lung cancer and melanoma (ASCO 2018, abstr #3025). Here we correlated plasma IL-8 and PD-L1 levels with OS in mCRPC patients. Methods: 201 metastatic CRPC patients had EDTA plasma available for this retrospective analysis. Patient eligibility included chemotherapy-naive mCRPC patients. The ELLA immunoassay platform (ProteinSimple, San Jose, CA) was utilized to quantitate plasma IL-8 and PD-L1. Cox regression assessed hazard ratio (HR) for OS using both categorical (median) and continuous (log-transformed) biomarkers. Results: In univariate analysis, higher plasma IL-8 levels were significantly associated with reduced OS when analyzed as a continuous variable (HR = 1.53; p = 0.003) and were of borderline significance at the median cutpoint (HR = 1.32; p = 0.069; 20.9 vs 31.5 mos median OS). Plasma PD-L1 levels were not significantly associated with OS when analyzed as a continuous variable (p = 0.17), but increased levels were significant when analyzed at the median cutpoint (HR = 1.36; p = 0.044; 21.9 vs 29.0 mos median OS). When plasma IL-8 and PD-L1 levels were combined (median cutpoints), plasma IL-8 high / PD-L1 high patients (n = 58) had a significantly shorter OS vs the plasma IL-8 low / PD-L1 low patients (n = 58) (HR = 1.69; p = 0.009; 19.3 vs 32.9 mos median OS, respectively). In multivariate analysis, when adjusted for biopsy Gleason score, age, PSA, and ECOG PS (all at time of blood draw), only high plasma IL-8 (on a continuous basis) was significantly associated with reduced OS (HR = 1.43; p = 0.019). Conclusions: In mCRPC patients, high plasma IL-8 and PD-L1 levels were associated with reduced OS (separately and combined). Circulating IL-8 and PD-L1 evaluation may inform prognosis in mCRPC and could be considered as biomarkers in future studies determining response to immune checkpoint inhibitor and anti-IL8 therapy.

Murine erythroid short-term radioprotection requires a BMP4-dependent, self-renewing population of stress erythroid progenitors

Acute anemic stress induces a systemic response designed to increase oxygen delivery to hypoxic tissues. Increased erythropoiesis is a key component of this response. Recovery from acute anemia relies on stress erythropoiesis, which is distinct from steady-state erythropoiesis. In this study we found that the bone morphogenetic protein 4-dependent (BMP4-dependent) stress erythropoiesis pathway was required and specific for erythroid short-term radioprotection following bone marrow transplantation. BMP4 signaling promoted the development of three populations of stress erythroid progenitors, which expanded in the spleen subsequent to bone marrow transplantation in mice. These progenitors did not correspond to previously identified bone marrow steady-state progenitors. The most immature population of stress progenitors was capable of self renewal while maintaining erythropoiesis without contribution to other lineages when serially transplanted into irradiated secondary and tertiary recipients. These data suggest that during the immediate post-transplant period, the microenvironment of the spleen is altered, which allows donor bone marrow cells to adopt a stress erythropoietic fate and promotes the rapid expansion and differentiation of stress erythroid progenitors. Our results also suggest that stress erythropoiesis may be manipulated through targeting the BMP4 signaling pathway to improve survival after injury.