NHANES III equations enhance early detection and mortality prediction of bronchiolitis obliterans syndrome after hematopoietic SCT

Stochastic modeling of obesity status in United States adults using Markov Chains: A nationally representative analysis of population health data from 2017-2020

Importance

The prevalence of obesity among United States adults has increased from 34.9% in 2013-2014 to 42.8% in 2017-2018. Developing methods to model the increase of obesity over-time is a necessity to know how to accurately quantify its cost and to develop solutions to combat this national public health emergency.

Methods

A cross-sectional cohort study using the publicly available National Health and Nutrition Examination Survey (NHANES 2017-2020) was conducted in individuals who completed the weight questionnaire and had accurate data for both weight at the time of survey and weight 10 years ago. To model the dynamics of obesity, a Markov transition state matrix was created, which allowed for the analysis of weight transitions over time. Bootstrap simulation was incorporated to account for uncertainty and generate multiple simulated datasets, providing a more robust estimation of the prevalence and trends in obesity within the cohort.

Results

Of the 6146 individuals who met the inclusion criteria, 3024 (49%) individuals were male and 3122 (51%) were female. There were 2252 (37%) White individuals, 1257 (20%) Hispanic individuals, 1636 (37%) Black individuals, and 739 (12%) Asian individuals. The average BMI was 30.16 (SD = 7.15), the average weight was 83.67 kilos (SD = 22.04), and the average weight change was a 3.27 kg (SD = 14.97) increase in body weight. A total of 2411 (39%) individuals lost weight, and 3735 (61%) individuals gained weight. 87 (1%) individuals were underweight (BMI <18.5), 2058 (33%) were normal weight (18.5 ≤ BMI <25), 1376 (22%) were overweight (25 ≤ BMI <30) and 2625 (43%) were in the obese category (BMI >30).

Conclusion

United States adults are at risk of transitioning from normal weight to the overweight or obese category. Markov modeling combined with bootstrap simulations can accurately model long-term weight status.

Covariate dependent Markov chains constructed with gradient boost modeling can effectively generate long-term predictions of obesity trends

IMPORTANCE

The prevalence of obesity among United States adults has increased from 30.5% in 1999 to 41.9% in 2020. However, despite the recognition of long-term weight gain as an important public health issue, there is a paucity of studies studying the long-term weight gain and building models for long-term projection.

METHODS

A retrospective, cross-sectional cohort study using the publicly available National Health and Nutrition Examination Survey (NHANES 2017-2020) was conducted in patients who completed the weight questionnaire and had accurate data for both weight at time of survey and weight ten years ago. Multistate gradient boost modeling classifiers were used to generate covariate dependent transition matrices and Markov chains were utilized for multistate modeling.

RESULTS

Of the 6146 patients that met the inclusion criteria, 3024 (49%) of patients were male and 3122 (51%) of patients were female. There were 2252 (37%) White patients, 1257 (20%) Hispanic patients, 1636 (37%) Black patients, and 739 (12%) Asian patients. The average BMI was 30.16 (SD = 7.15), the average weight was 83.67 kilos (SD = 22.04), and the average weight change was a 3.27 kg (SD = 14.97) increase in body weight (Fig. 1). A total of 2411 (39%) patients lost weight, and 3735 (61%) patients gained weight (Table 1). We observed that 87 (1%) of patients were underweight (BMI < 18.5), 2058 (33%) were normal weight (18.5 ≤ BMI < 25), 1376 (22%) were overweight (25 ≤ BMI < 30) and 2625 (43%) were obese (BMI > 30). From analysis of the transitions between normal/underweight, overweight, and obese, we observed that after 10 years, of the patients who were underweight, 65% stayed underweight, 32% became normal weight, 2% became overweight, and 2% became obese. After 10 years, of the patients who were normal weight, 3% became underweight, 78% stayed normal weight, 17% became overweight, and 2% became obese. Of the patients who were overweight, 71% stayed overweight, 0% became underweight, 14% became normal weight, and 15% became obese. Of the patients who were obese, 84% stayed obese, 0% became underweight, 1% became normal weight, and 14% became overweight.

CONCLUSIONS

United States adults are at risk of transitioning from normal weight to becoming overweight or obese. Covariate dependent Markov chains constructed with gradient boost modeling can effectively generate long-term predictions.

Prospective phase II trial of montelukast to treat bronchiolitis obliterans syndrome after hematopoietic cell transplant and investigation into BOS pathogenesis

BACKGROUND

Bronchiolitis obliterans syndrome (BOS) is a severe manifestation of chronic graft-versus-host disease (cGVHD) following hematopoietic cell transplantation (HCT). Montelukast interrupts cysteinyl leukotriene activity and may diminish the activation and homing of cells to bronchioles and subsequent fibrosis.

OBJECTIVE

We performed a prospective phase II trial to test whether montelukast altered lung decline for patients with BOS after HCT.

STUDY DESIGN

We performed a single arm, open-label, multi-institutional study with primary endpoints of: i) FEV1 stability or improvement (<15% decline) and ii) slope of FEV1<1 point decline after six months treatment. Secondary endpoints included symptom and functional response, and immune correlates investigating the role of leukotrienes in BOS progression.

RESULTS

25 patients enrolled with moderate to severe lung disease after three months of stable cGVHD therapy. Montelukast was well-tolerated and no patient required escalation of BOS-directed therapy. At the primary endpoint, all evaluable patients (n=23) met criteria for treatment success using FEV1% predicted, and all but one had stable or improved FEV1 slope. In those with >5% FEV1 improvement, clinically meaningful improvements were seen in the Lee scores of breathing, energy, and mood. Improvements in the Human Activity Profile and 6-minute-walk test were observed in those with <5% FEV1 decline. Overall survival was 87% at two-years. Immune correlates showed elevated leukotriene receptor levels on blood eosinophils and monocytes vs. healthy controls, elevated urine leukotrienes in 45% of cohort, and cysteinyl leukotriene receptors on bronchoalveolar lavage subsets and a predominance of Th2 T cells, all pre-treatment.

CONCLUSIONS

These data suggest that montelukast may safely halt progression of BOS after HCT and that leukotrienes may play a role in the biology of BOS.

Relationship between FEV1 decline and mortality in patients with bronchiolitis obliterans syndrome-a systematic literature review

BACKGROUND

Bronchiolitis obliterans syndrome (BOS) is one of the most severe complications and the leading cause of late mortality and morbidity after lung transplantation (LT) and allogeneic hematopoietic stem cell transplantation (allo-HSCT). No approved treatment for BOS is available. This review aimed to systematically identify and summarise the findings regarding the relationship between FEV₁ decline and mortality in patients who developed BOS following LT or allo-HSCT.

METHODS

A systematic literature search was performed in the Medline, Embase and Cochrane reviews databases. Of the 501 potential studies identified 25 met inclusion criteria and were analysed.

RESULTS

Overall, 13 studies reported a relationship between FEV₁ and mortality, and 12 studies reported both mortality and FEV₁ results but did not investigate the relationship between them. There was heterogeneity in the analyses, which investigated the relationship between FEV₁ decline and mortality across the studies in terms of levels of lung functioning, comparison to a control group, treatment, and statistical methodology; nevertheless, a clear and consistent increase in the risk of death associated with FEV₁ decrease was seen in the analysed studies.

CONCLUSIONS

The systematic literature review identified studies and findings that support a relationship between FEV₁ and mortality, with a decrease in FEV₁ being statistically associated with increased risk of death. Knowing that lower FEV₁ levels are associated with higher mortality rates may help assess the condition of a patient with BOS and monitor future treatment effectiveness. However, more evidence is needed to further investigate this relationship and to verify its clinical usefulness.

How I treat bronchiolitis obliterans syndrome after hematopoietic stem cell transplantation

In past years, a diagnosis of bronchiolitis obliterans syndrome (BOS) after allogeneic hematopoietic cell transplant (HCT) conferred nearly universal mortality secondary to lack of consensus for diagnostic criteria, poorly understood disease pathogenesis, and very few studies of therapeutic or supportive care interventions. Recently, however, progress has been made in these areas: revised consensus diagnostic guidelines are now available, supportive care has improved, there is greater understanding of potential mechanisms of disease, and prospective trials are being conducted. This article describes these advances and provides suggestions to optimize therapy for patients with BOS after HCT.

Prognostic role of FEV1 for survival in bronchiolitis obliterans syndrome after allogeneic hematopoietic stem cell transplantation

BACKGROUND

Bronchiolitis obliterans syndrome (BOS) can occur after hematopoietic stem cell transplantation (HSCT) and is associated with significant mortality. We investigated the role of forced expiratory volume in one s (FEV1 ) as a prognostic marker in BOS after HSCT.

METHODS

Among all patients who underwent HSCT between December 1993 and November 2013 at a tertiary center in South Korea, 1187 patients were enrolled. Patient medical records were retrospectively analyzed to evaluate the prognostic factors associated with survival in these cases.

RESULTS

During a median follow-up period of 30.7 months after HSCT, 82 patients (6.9%) were diagnosed with BOS. The mean FEV1 of the BOS patients was 34.7% of predicted, and the mean FEV1 of 31 of these patients (37.8%) was <30% of predicted. The estimated overall survival rate for BOS patients excluding three patients who received lung transplantation was 74% at three yr from BOS diagnosis. Multivariate analysis showed that diagnosis of BOS within six months and FEV1 < 30% of predicted at the time of BOS diagnosis were associated with shorter survival.

CONCLUSIONS

An FEV1 < 30% of predicted at the time of diagnosis is significantly associated with an increased risk of death in patients with BOS after HSCT.

MSC therapy attenuates obliterative bronchiolitis after murine bone marrow transplant

RATIONALE

Obliterative bronchiolitis (OB) is a significant cause of morbidity and mortality after lung transplant and hematopoietic cell transplant. Mesenchymal stromal cells (MSCs) have been shown to possess immunomodulatory properties in chronic inflammatory disease.

OBJECTIVE

Administration of MSCs was evaluated for the ability to ameliorate OB in mice using our established allogeneic bone marrow transplant (BMT) model.

METHODS

Mice were lethally conditioned and received allogeneic bone marrow without (BM) or with spleen cells (BMS), as a source of OB-causing T-cells. Cell therapy was started at 2 weeks post-transplant, or delayed to 4 weeks when mice developed airway injury, defined as increased airway resistance measured by pulmonary function test (PFT). BM-derived MSC or control cells [mouse pulmonary vein endothelial cells (PVECs) or lung fibroblasts (LFs)] were administered. Route of administration [intratracheally (IT) and IV] and frequency (every 1, 2 or 3 weeks) were compared. Mice were evaluated at 3 months post-BMT.

MEASUREMENTS AND MAIN RESULTS

No ectopic tissue formation was identified in any mice. When compared to BMS mice receiving control cells or no cells, those receiving MSCs showed improved resistance, compliance and inspiratory capacity. Interim PFT analysis showed no difference in route of administration. Improvements in PFTs were found regardless of dose frequency; but once per week worked best even when administration began late. Mice given MSC also had decreased peribronchiolar inflammation, lower levels of hydroxyproline (collagen) and higher frequencies of macrophages staining for the alternatively activated macrophage (AAM) marker CD206.

CONCLUSIONS

These results warrant study of MSCs as a potential management option for OB in lung transplant and BMT recipients.