Imaging for precision medicine: can V-P SPECT measure mepolizumab response in asthma?

Ventilation Heterogeneity Is a Treatable Trait in Severe Asthma

BACKGROUND

Ventilation heterogeneity (VH) is a feature of asthma and indicates small airway disease. Nuclear imaging methods assess VH, which can facilitate clinical diagnosis and further our understanding of disease aetiology.

OBJECTIVE

We sought to assess VH in severe eosinophilic asthma (SEA) using ventilation/perfusion single-photon emission computed tomography (V/P SPECT), and to assess its use as an objective test of the effect of biologic treatment for ventilation defects in SEA.

METHODS

Adults (≥18 y) with severe asthma were recruited to participate in a cross-sectional observational study. Participants underwent a clinical assessment and V/P SPECT CT using Technegas as the ventilation agent. Measures were repeated for a nested before-after treatment study in people with SEA commencing biologics.

RESULTS

A total of 62 participants with severe asthma were recruited. From this, 38 participants with SEA were included in the before-after study. The VH was associated with clinical variables such as lung function impairment and significantly improved after monoclonal antibody treatment in the severe asthma group. The changes in VH correlated with change in post bronchodilator forced expiratory volume in 1 second (FEV1) %predicted (r = -0.503; P = .001) and post bronchodilator FEV1/FVC (forced vital capacity) (r = -0.415; P = .01).

CONCLUSIONS

The VH is clinically significant, measurable, and treatable, which establishes VH as a treatable trait in severe asthma.

Quantitative analysis of lung function and airway remodeling using ventilation/perfusion single photon emission tomography/computed tomography and HRCT in patients with chronic obstructive pulmonary disease and asthma

OBJECTIVE

To investigate the role of V/P SPECT/CT and HRCT quantitative parameters in evaluating COPD and asthma disease severity, airway obstructivity-grade, ventilation and perfusion distribution patterns, airway remodeling, and lung parenchymal changes.

METHOD

Fifty-three subjects who underwent V/P SPECT/CT, HRCT, and pulmonary function tests (PFTs) were included. Preserved lung ventilation (PLVF), perfusion function (PLPF), airway obstructivity-grade (OG), proportion of anatomical volume, ventilation and perfusion contribution of each lobe, and V/P distribution patterns were evaluated using V/P SPECT/CT. The quantitative parameters of HRCT included CT bronchial and CT pulmonary function parameters. In addition, the correlation and difference of V/P SPECT/CT-, HRCT-, and PFT-related parameters were compared.

RESULTS

There was a statistically significant difference between severe asthma and severe-very severe COPD in CT bronchial parameters, like WA, LA and AA, in the lung segment airways (P < 0.05). CT bronchial parameters, like as WT and WA, were statistically significant (p < 0.05) among asthma patients. The EI of severe-very severe COPD was different from that of the disease severity groups in asthma patients (P < 0.05). The airway obstructivity-grade, PLVF and PLPF differed significantly among the severe-very severe COPD and mild-moderate asthma patients (P < 0.05). And the PLPF was statistically significant among the disease severity groups in asthma and COPD (P < 0.05). OG and PLVF, PLPF, and PFT parameters were significantly correlated, with the FEV1 correlation being the most significant (r = - 0.901, r = 0.915, and r = 0.836, respectively; P < 0.01). There was a strong negative correlation between OG and PLVF (r = - 0.945) and OG and PLPF (r = - 0.853) and a strong positive correlation between PLPF and PLVF (r = 0.872). In addition, OG, PLVF, and PLPF were moderately to strongly correlated with CT lung function parameters (r = - 0.673 to - 0.839; P < 0.01), while lowly to moderately correlated with most CT bronchial parameters (r = - 0.366 to - 0.663, P < 0.01). There were three different V/P distribution patterns, including matched, mismatched, and reverse mismatched patterns. Last, the CT volume overestimated the contribution in the upper lobes and underestimated the lower lobes' contribution to overall function.

CONCLUSIONS

Quantitative assessment of ventilation and perfusion abnormalities and the degree of pulmonary functional loss by V/P SPECT/CT shows promise as an objective measure to assess the severity of disease and lung function to guide localized treatments. There are differences between HRCT parameters and SPECT/CT parameters among the disease severity groups in asthma and COPD, which may enhance, to some extent, the understanding of complex physiological mechanisms in asthma and COPD.

3D-Ring CZT System With New Low- and Medium-Energy Range: Ultrafast Dual-Isotope Lung SPECT/CT Improvement

ABSTRACT

New 3D-ring CZT systems with low- and medium-energy-range detectors allow for simultaneous dual-isotope lung scintigraphy. We compared 10-, 7-, 5-, and 3-minute acquisitions for 99m Tc and 81m Kr performed simultaneously on StarGuide CZT-SPECT/CT and reframed in 50 patients. Ventilation/perfusion mismatches were calculated (mean, 15.6% ± 28%), and Spearman correlation coefficients of mismatches were 0.994, 0.994, and 0.984 between 10- and 7-, 5-, and 3-minute acquisitions, respectively. No visual difference in image quality or final diagnosis was found. 3D-ring CZT-SPECT with low and medium energy range detectors allows ultrafast dual-isotope lung scintigraphy up to 3 minutes.

The Role of Molecular Imaging in Personalized Medicine

The concept of personalized medicine refers to the tailoring of medical treatment to each patient's unique characteristics. Scientific advancements have led to a better understanding of how a person's unique molecular and genetic profile makes them susceptible to certain diseases. It provides individualized medical treatments that will be safe and effective for each patient. Molecular imaging modalities play an essential role in this aspect. They are used widely in screening, detection and diagnosis, treatment, assessing disease heterogeneity and progression planning, molecular characteristics, and long-term follow-up. In contrast to conventional imaging approaches, molecular imaging techniques approach images as the knowledge that can be processed, allowing for the collection of relevant knowledge in addition to the evaluation of enormous patient groups. This review presents the fundamental role of molecular imaging modalities in personalized medicine.

Immunotherapy: State-of-the-art review of therapies and theratypes

Through its disease-modifying potential, immunotherapy is the keystone to curing allergic diseases. Allergen immunotherapy, applied for more than a century, is currently supported by novel modalities such as mAb-based therapies or small molecules targeting the key nodes of the allergic inflammation network. In this review, a summary of the most significant advances in immunotherapy is presented, addressing not only novel approaches to stratifying patients but also major controlled clinical trials and real-world evidence that strengthen the role of immunotherapy in the treatment of allergies.

Advances and highlights in asthma in 2021

Last year brought a significant advance in asthma management, unyielding to the pressure of the pandemics. Novel key findings in asthma pathogenesis focus on the resident cell compartment, epigenetics and the innate immune system. The precision immunology unbiased approach was supplemented with novel tools and greatly facilitated by the use of artificial intelligence. Several randomised clinical trials and good quality real-world evidence shed new light on asthma treatment and supported the revision of several asthma guidelines (GINA, Expert Panel Report 3, ERS/ATS guidelines on severe asthma) and the conception of new ones (EAACI Guidelines for the use of biologicals in severe asthma). Integrating asthma management within the broader context of Planetary Health has been put forward. In this review, recently published articles and clinical trials are summarised and discussed with the goal to provide clinicians and researchers with a concise update on asthma research from a translational perspective.