Cardiovascular disease in Alpha 1 antitrypsin deficiency: an observational study assessing the role of neutrophil proteinase activity and the suitability of validated screening tools

BACKGROUND

Alpha 1 Antitrypsin Deficiency (AATD) is a rare, inherited lung disease which shares features with Chronic Obstructive Pulmonary Disease (COPD) but has a greater burden of proteinase related tissue damage. These proteinases are associated with cardiovascular disease (CVD) in the general population. It is unclear whether patients with AATD have a greater risk of CVD compared to usual COPD, how best to screen for this, and whether neutrophil proteinases are implicated in AATD-associated CVD. This study had three aims. To compare CVD risk in never-augmented AATD patients to non-AATD COPD and healthy controls (HC). To assess relationships between CVD risk and lung physiology. To determine if neutrophil proteinase activity was associated with CVD risk in AATD. Cardiovascular risk was assessed by QRISK2® score and aortic stiffness measurements using carotid-femoral (aortic) pulse wave velocity (aPWV). Medical history, computed tomography scans and post-bronchodilator lung function parameters were reviewed. Systemic proteinase 3 activity was measured. Patients were followed for 4 years, to assess CVD development.

RESULTS

228 patients with AATD, 50 with non-AATD COPD and 51 healthy controls were recruited. In all COPD and HC participants, QRISK2® and aPWV gave concordant results (with both measures either high or in the normal range). This was not the case in AATD. Once aPWV was adjusted for age and smoking history, aPWV was highest and QRISK2® lowest in AATD patients compared to the COPD or HC participants. Higher aPWV was associated with impairments in lung physiology, the presence of emphysema on CT scan and proteinase 3 activity following adjustment for age, smoking status and traditional CVD risk factors (using QRISK2® scores) in AATD. There were no such relationships with QRISK2® in AATD. AATD patients with confirmed CVD at four-year follow up had a higher aPWV but not QRISK2® at baseline assessment.

CONCLUSION

aPWV measured CVD risk is elevated in AATD. This risk is not captured by QRISK2®. There is a relationship between aPWV, lung disease and proteinase-3 activity. Proteinase-driven breakdown of elastin fibres in large arteries and lungs is a putative mechanism and forms a potential therapeutic target for CVD in AATD.

To What Extent do Social Determinants of Health Modulate Presentation, ITU Admission and Outcomes among Patients with SARS-COV-2 Infection? An Exploration of Household Overcrowding, Air Pollution, Housing Quality, Ethnicity, Comorbidities and Frailty

Background

Internationally, researchers have called for evidence to support tackling health inequalities during the severe acute respiratory syndrome coronavirus 2 (COVID19) pandemic. Despite the 2020 Marmot review highlighting growing health gaps between wealthy and deprived areas, studies have not explored social determinants of health (ethnicity, frailty, comorbidities, household overcrowding, housing quality, air pollution) as modulators of presentation, intensive care unit (ITU) admissions and outcomes among COVID19 patients. There is an urgent need for studies examining social determinants of health including socioenvironmental risk factors in urban areas to inform the national and international landscape.

Methods

An in-depth retrospective cohort study of 408 hospitalized COVID19 patients admitted to the Queen Elizabeth Hospital, Birmingham was conducted. Quantitative data analyses including a two-step cluster analysis were applied to explore the role of social determinants of health as modulators of presentation, ITU admission and outcomes.

Results

Patients admitted from highest Living Environment deprivation indices were at increased risk of presenting with multi-lobar pneumonia and, in turn, ITU admission whilst patients admitted from highest Barriers to Housing and Services (BHS) deprivation Indies were at increased risk of ITU admission. Black, Asian and Minority Ethnic (BAME) patients were more likely, than Caucasians, to be admitted from regions of highest Living Environment and BHS deprivation, present with multi-lobar pneumonia and require ITU admission.

Conclusion

Household overcrowding deprivation and presentation with multi-lobar pneumonia are potential modulators of ITU admission. Air pollution and housing quality deprivation are potential modulators of presentation with multi-lobar pneumonia. BAME patients are demographically at increased risk of exposure to household overcrowding, air pollution and housing quality deprivation, are more likely to present with multi-lobar pneumonia and require ITU admission. Irrespective of deprivation, consideration of the Charlson Comorbidity Score and the Clinical Frailty Score supports clinicians in stratifying high risk patients.

Post-traumatic stress disorder dimensions and asthma morbidity in World Trade Center rescue and recovery workers

OBJECTIVE

Using data from a cohort of World Trade Center (WTC) rescue and recovery workers with asthma, we assessed whether meeting criteria for post-traumatic stress disorder (PTSD), sub-threshold PTSD, and for specific PTSD symptom dimensions are associated with increased asthma morbidity.

METHODS

Participants underwent a Structured Clinical Interview for Diagnostic and Statistical Manual to assess the presence of PTSD following DSM-IV criteria during in-person interviews between December 2013 and April 2015. We defined sub-threshold PTSD as meeting criteria for two of three symptom dimensions: re-experiencing, avoidance, or hyper-arousal. Asthma control, acute asthma-related healthcare utilization, and asthma-related quality of life data were collected using validated scales. Unadjusted and multiple regression analyses were performed to assess the relationship between sub-threshold PTSD and PTSD symptom domains with asthma morbidity measures.

RESULTS

Of the 181 WTC workers with asthma recruited into the study, 28% had PTSD and 25% had sub-threshold PTSD. Patients with PTSD showed worse asthma control, higher rates of inpatient healthcare utilization, and poorer asthma quality of life than those with sub-threshold or no PTSD. After adjusting for potential confounders, among patients not meeting the criteria for full PTSD, those presenting symptoms of re-experiencing exhibited poorer quality of life (p = 0.003). Avoidance was associated with increased acute healthcare use (p = 0.05). Sub-threshold PTSD was not associated with asthma morbidity (p > 0.05 for all comparisons).

CONCLUSIONS

There may be benefit in assessing asthma control in patients with sub-threshold PTSD symptoms as well as those with full PTSD to more effectively identify ongoing asthma symptoms and target management strategies.

Creation of an arteriovenous fistula is associated with significant acute local and systemic changes in microvascular function

BACKGROUND

Native arteriovenous fistulae (AVF) are the vascular access of choice for haemodialysis. The consequences of AVF formation on microvascular function, locally or systemically, are unknown.

METHODS

We recruited 43 predialysis patients undergoing AVF formation. Patients were studied 2 weeks prior to the planned AVF operation and 2 weeks postoperatively. Thirteen patients with failed AVF were subsequently utilised as sham controls. Laser Doppler perfusion imaging was used to measure subcutaneous microvascular blood flow. Microvascular function was assessed as an increase in perfusion in response to iontophoretic administration of vasodilatory stimuli assessing endothelial-dependent (ED) and non-endothelial-dependent (NED) vasodilatation.

RESULTS

Patients with successful AVF formation had a significantly reduced ED vasodilatation in the fistula arm (-36 ± 46%, p < 0.001). Only NED vasodilatation was significantly reduced in the non-fistula arm (23 ± 40%, p = 0.01). Patients who had an unsuccessful AVF operation exhibited no recordable changes.

CONCLUSIONS

Formation of an AVF was associated with local and remote changes in microcirculation. Further assessments are underway to examine the contributions of local shear stress, vasoreactive substances and the autonomic responses. Although the clinical significance of these findings is not yet clear, it is intriguing that AVF formation is associated with such widespread and profound changes in microperfusion.

A multisite physician's office laboratory evaluation of an immunological method for the measurement of HbA1c

OBJECTIVE

To evaluate the clinical performance of a new immunological HbA1c method in physicians' office laboratories.

RESEARCH DESIGN AND METHODS

Three physicians' offices participated in the evaluations. The clinicians routinely use HbA1c test results to monitor their patients' long-term blood glucose control. Precision and interlaboratory variability were assessed using three levels of lyophilized controls. Correlation of the method's results to currently available laboratory methods was made. Comparison of finger-stick (capillary) results to venous EDTA whole blood results was made on 134 patients. Physician and laboratory personnel input was evaluated with regard to the clinical utility of the system.

RESULTS

The CVW and CVB were a maximum of 4.5 and 4.4% for the immunoassay system on three levels of control materials at the three sites. Interlaboratory variability among the control means was found to be 4.9-5.4, 8.0-8.3, and 11.7-12.0% HbA1c. Correlation coefficients (r) ranged from 0.95 to 0.99. There was a positive bias by the DCA 2000 compared with the in-house method at site 1. Minimal negative biases were seen by the DCA 2000 with comparative methods used at sites 2 and 3. Median percentage differences with the comparative methods were 12, -1.4, and -5.6%. Comparison of capillary to venous sample results, from the DCA 2000, showed no clinically significant differences. Operator and physician feedback were positive with respect to technical ease in performance of the test and accuracy of results.

CONCLUSIONS

Precision was acceptable and interlaboratory variability was low. The immunological method correlated well with manual ion-exchange and automated HPLC methods. The small sample size and good comparison between capillary and venous sample results make fingerstick sampling acceptable. The method provided immediate test results (within 9 min) to the clinicians.

Immediate HbA1c results. Performance of new HbA1c system in pediatric outpatient population

OBJECTIVE

This study compared the performance of a new device that uses an IA to measure HbA1c in 9 min with a 1-microliter capillary blood sample with AC and CE methods in both nondiabetic and diabetic pediatric patients.

RESEARCH DESIGN AND METHODS

Two hundred seven pediatric subjects (103 nondiabetic, 104 with insulin-dependent diabetes mellitus) had HbA1c measured with the IA method and compared with total GHb values determined by AC and HbA1 by the CE method with the same whole-blood capillary aliquot. Glucose values were also obtained from the same blood samples.

RESULTS

Correlations and regression analyses show excellent correspondence between the three assays. The correlation between the AC and CE methods is 0.98 (P less than 0.001) with a slope of 1.615 +/- 0.0125 and intercept of 4.00 +/- 0.20. The correlation between the IA and AC methods is 0.99 (P less than 0.001) with a slope of 0.608 +/- 0.007 and intercept of 1.326 +/- 0.066. The correlation between the IA and CE methods is 0.97 (P less than 0.001), with a slope of 0.983 +/- 0.018 and intercept of 1.122 +/- 0.153. The average difference and average percentage difference between methods were also significant (P less than 0.001), reflecting the differences in GHb components measured. There was a significant correlation (P less than 0.001) between each method and glucose values (IA r = 0.72, AC r = 0.70, CE r = 0.73). Within-run precision for IA ranged from 1.7 to 3.5% and between-run precision 2.7 to 4.1%.

CONCLUSIONS

Study results suggest that the IA method gives extremely accurate and reliable values over the clinical range of interest. The instrument is small, portable, easy to use, and provides information within 9 min for both physicians and patients.

Cholesterol assays in the Seralyzer instrument

We evaluated the Seralyzer instrument for the assay of serum cholesterol and compared it to the Kodak Ektachem method. The Seralyzer showed good accuracy in the analysis of cholesterol in Abell-Kendall-verified serum pools, and the bias from the expected value was small in all cases but one. The Seralyzer exhibited CVs of less than 5% in all cases and good comparison with the Ektachem method. The Seralyzer is easy to use; however, some training in the proper pipetting technique is necessary. The Seralyzer meets medical needs criteria of total error greater than 5% from the true cholesterol value.