Profiling peripheral B-cell subtypes most predictive for cardiac allograft rejection

Introduction

B-cells have been strongly implicated in cardiac allograft rejection (CAR). Recently, however, the CTOT-11 trial showed that depleting mature CD20+ B-cells did not reduce rates of rejection in cardiac allograft recipients and unexpectedly increased the severity of allograft vasculopathy. Therefore, it can be hypothesized that differing phenotypic subtypes of B-cells correspond with different biological mechanisms relating to CAR. Though, current applications to quantify these subtypes of immune cells, i.e with immunohistochemistry or flow cytometry, are often restricted by limited cell markers and cost-burden; therefore, we demonstrate a novel deconvolution method, FARDEEP, that has been validated to accurately enumerate peripheral blood mononuclear cell-subtypes (PBMCs) in a quicker and more cost-effective manner.

Purpose

To better understand the association of different B-cell subtypes in CAR by identifying the B-cell subtype most predictive for pathologically defined rejection.

Methods

The machine learning tool, FARDEEP, was trained with the transcriptomic signatures of 29 PBMC subtypes, characterized by previous single-cell RNA experiments. FARDEEP then was used to deconvolute data-mined RNA from 259 blood samples from 98 cardiac allograft recipients enrolled in the CARGO study (GSE2445). Random forest tree (RF) was then used to analyze the levels of deconvoluted subtypes to predict the severity of rejection assessed by endomyocardial biopsy. Finally, RF was used to identify the subtypes of PBMCs most valuable in predicting rejection.

Results

Out of the 259 samples with consensus pathological readings, 140 had a consensus International Society of Heart and Lung Transplant grade of 0, 63 with grade 1a, 31 with grade 1b, and 25 with grade 3a or higher. We grouped biopsy samples with grade 0, 1a, and 1b as “low-risk” rejection (n=234). 3a or higher samples were grouped as “high-risk” (n=25). There were no grade 2s in the dataset. According to the dataset, blood was extracted from patients on average 72.5 days post-transplant. The RF had good performance in predicting rejection severity. (Figure 1a) CD20- plasmablast cells were stronger predictors for differentiating high-risk from low-risk compared to CD20+ B-cell populations (i.e B Naive and B Memory cells). (Figure 1b) Overall, however, dendritic cells (DCs), neutrophils, monocytes, and basophils were the strongest predictors for rejection.

Conclusion

Our findings support the results from the CTOT-11 trial showing that CD20+ B-cells may not contribute to CAR as significantly as seen with other PBMC subtypes. Instead, we showed that among B-cells, CD20- plasmablasts were more likely associated with CAR, possibly explaining why targeting CD20 was ineffective in preventing rejection. Thus, targeting plasmablast-associated markers could potentially be more useful to prevent CAR.

Model Performance with Variables

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): 1) Society of Academic Emergency Medicine Foundation; 2) The Jewish Fund

Machine Learning Applications in the Neuro ICU: A Solution to Big Data Mayhem?

The neurological ICU (neuro ICU) often suffers from significant limitations due to scarce resource availability for their neurocritical care patients. Neuro ICU patients require frequent neurological evaluations, continuous monitoring of various physiological parameters, frequent imaging, and routine lab testing. This amasses large amounts of data specific to each patient. Neuro ICU teams are often overburdened by the resulting complexity of data for each patient. Machine Learning algorithms (ML), are uniquely capable of interpreting high-dimensional datasets that are too difficult for humans to comprehend. Therefore, the application of ML in the neuro ICU could alleviate the burden of analyzing big datasets for each patient. This review serves to (1) briefly summarize ML and compare the different types of MLs, (2) review recent ML applications to improve neuro ICU management and (3) describe the future implications of ML to neuro ICU management.

Immunization of Children with Cancer in India Treated with Chemotherapy - Consensus Guideline from the Pediatric Hematology-Oncology Chapter and the Advisory Committee on Vaccination and Immunization Practices of the Indian Academy of Pediatrics

JUSTIFICATION

Children with cancer need to be immunized against the common vaccine-preventable diseases after completion and sometimes during ongoing treatment of cancer. However, the immunization schedule for these children needs to be altered due to disease and treatment related immune-suppression. Consequently, there are many guidelines/practice statements from around the world to address this issue, however, there is no such comprehensive guideline from India catering to the need of Indian children with cancer.

PROCESS

A guideline was drafted after reviewing the available literature. The draft guideline was discussed and modified in a meeting attended by pediatric oncologists from the PHO chapter and vaccine experts from the ACVIP of the IAP. Subsequently, the modified draft was reviewed and recommendations were finalized.

OBJECTIVES

To review the current evidence and generate a nationally relevant guideline for immunization of children receiving chemotherapy for cancer.

RECOMMENDATIONS

Live vaccines are contraindicated during and up to 6 months after end of chemotherapy. Non-live vaccines are also best given after 6 months from the end of treatment for durable immunity. Annual inactivated influenza vaccine is the only vaccine recommended for all children during chemotherapy whereas hepatitis B vaccine is recommended only for previously unimmunised children with risk of transfusion associated transmission of infection. Post-treatment re-immunization/catch-up schedule largely depends on the pre-chemotherapy immunization status. Sibling immunization should continue uninterrupted except for oral polio vaccine which needs to be substituted by the injectable vaccine. Inactivated influenza vaccine is recommended and varicella vaccine is encouraged for all contacts including siblings.

Optic neuropathy associated with dengue fever

PURPOSE

To report a case series of three patients of optic neuropathy associated with dengue fever.

METHODS

Observational case series.

RESULTS

Three patients aged of 19, 31, and 40 years (cases 1, 2, and 3) complained of unilateral blurring of vision within a week of being diagnosed with dengue fever. Their presenting visual acuities were counting fingers in cases 1 and 2, and 6/6 in case 3, with features suggestive of optic neuropathy. Two of the three patients (cases 2 and 3) had bilateral ocular signs. The visual acuity recovered to 6/9 in case 1, worsened to no light perception in case 2, and remained unchanged in case 3.

CONCLUSIONS

Although spontaneous visual recovery is possible, optic neuropathy associated with dengue fever may result in severe and permanent visual loss.

Refractory hyperkalaemia due to trimethoprim, successfully treated with fludrocortisone

We report a case of intractable hyperkalaemia in an elderly patient with myeloma, who received conventional dose of trimethoprim-sulfamethoxazole and hyperkalaemia resolved following therapy with fludrocortisone. We recommend monitoring of serum potassium in high-risk patients receiving conventional doses of trimethoprim-sulfamethoxazole for 5 or more days.

Montelukast - evaluation in 6 to 14 years old children with persistent asthma - pediatric montelukast study group

OBJECTIVE

The suffering of children with asthma as a persistent illness is present in approximately 10% of the total population. The prevalent treatment regimens available has been the inhaled coticosteroids and short acting bronchodialators. Though the therapies are rational and well accepted but at the cost of side effects on chronic use. The changing definitions and guidelines with regard to asthma have given a classified slot to newer treatments like leukotriene receptor antagonists (LTRAs). The aim of the present study was to study the efficacy and tolerability of montelukast in the treatment of Indian pediatric patients aged 6 to 14 years with chronic asthma.

METHODS

It was a prospective, open, non-comparative multicentric study. 881 Children (Mean age 11.83+/- 3.12 years) were included. Patients fulfilling the inclusion criteria were given one mouth dissolving 5 mg montelukast tablet daily in the evening for 30 days.

RESULTS

There was an overall improvement in all the efficacy parameters. The daytime total asthma score decreased from 9.55 +/- 1.52 to 3.59 +/- 2.10. The average number of asthma attacks over the last 4 weeks decreased from 1.14+/- 1.19 to 0.28+/-0.57. The number of nocturnal awakenings fell from 1.54+/-0.78 to 0.43+/-0.54. FEV1 (L) [Predicted] improved by 21.18%). PEFR (L/min.) improved by 34.69%). Approximately 45% physicians rated the treatment as excellent, 30% as very good, 18% as good, 7% as fair and none as poor.

CONCLUSION

Montelukast administered once daily improved efficacy end-points and was well tolerated in pediatric patients with chronic persistent asthma establishing itself as a valuable treatment option to current asthma therapies in 6 to 14 years old patients.

The annual risk of tuberculous infection in the eastern zone of India

SETTING

Rural and urban areas of eight selected districts in the eastern zone of India.

OBJECTIVES

To estimate the annual risk of tuberculous infection (ARTI).

STUDY DESIGN

A community-based, cross-sectional tuberculin survey was conducted among children aged 1-9 years residing in a sample of rural and urban areas. Stratified two-stage cluster sampling was adopted for selection of rural and urban clusters. A total of 40964 children in 515 clusters underwent tuberculin testing and reading with 1TU PPD RT23 with Tween 80; the maximum transverse diameter of induration was measured about 72 h after the test.

RESULTS

A bacille Calmette-Gúerin (BCG) scar was observed in 51.5% of the test-read children. The frequency distribution of tuberculin reaction size among 19332 children without BCG scar was found to be bimodal, with the mode of reactions attributable to infection with tubercle bacilli at 20 mm. The prevalence of infection was estimated as 6.9%. The ARTI computed from the estimated prevalence was 1.3%. Children residing in the urban areas were found to be at a significantly higher risk of infection than those residing in rural areas.

CONCLUSION

The high rate of ARTI in the eastern zone of India suggests a need for committed, sustained action in provision of quality tuberculosis control services.