Phenotyping exercise limitation of patients with Interstitial Fibrosing Lung Disease: the importance of exercise hemodynamics

INTRODUCTION AND OBJECTIVE

Left-heart dysfunction and pulmonary vasculopathy are increasingly recognized as contributing factors of exercise capacity limitation in interstitial fibrosing lung disease (IFLD). Moreover, the clinical significance of exercise pulmonary hypertension (ePH) in pulmonary and cardiac diseases has been documented, representing a risk factor for decreased exercise capacity and survival, progression to resting pulmonary hypertension (PH) and overall clinical worsening. We conducted a prospective study aiming at: (a) assessing the prevalence of PH and ePH in a cohort of 40 functionally limited patients with IFLD, (b) determining the post-capillary (postC) or pre-capillary (preC) etiology of either PH or ePH in this cohort, and (c) examining the correlations between invasively and non-invasively measured exercise variables among hemodynamic groups.

PATIENTS AND METHODS

40 IFLD patients underwent cardiopulmonary evaluation, including: clinical examination, lung function tests, 6-minute walking test, heart ultrasonography, cardiopulmonary exercise test and, finally, right heart catheterization (RHC). Resting hemodynamic evaluation was followed by the exercise protocol proposed by Herve et al, using a bedside cycle ergometer in the supine position. Abnormal elevation of mean pulmonary artery pressure (mPAP) above 30mmHg during exercise, with respect to abnormal elevation of cardiac output (CO) below 10 L/min (mPAP-CO ratio ⩾3 mmHg·min·L-1) was used to define ePH (Herve et al, 2015). Secondary hemodynamic evaluation involved detection of abnormal pulmonary arterial wedge pressure (PAWP) increase at peak exercise in relation to CO. Specifically, ΔPAWP/ΔCO >2 mmHg/L per minute determined an abnormal PAWP elevation (Bentley et al, 2020).

RESULTS

Among the 40-patient cohort, 25% presented postC PH, 37.5% preC PH, 27.5% ePH, with the remaining 10% recording normal hemodynamics. PAWP evaluation during exercise revealed a postC etiology in 4 out of the 11 patients presenting ePH, and a postC etiology in 6 out of the 15 patients presenting resting preC PH. Mean values of non-invasive variables did not display statistically significant differences among hemodynamic groups, except for: diffusing capacity for carbon monoxide (DLCO), carbon monoxide transfer coefficient (KCO) and the ratio of functional vital capacity to DLCO (FVC%/DLCO%), which were lower in both ePH and PH groups (p < 0.05). Resting values of CO, cardiac index (CI), stroke volume (SV) and pulmonary vascular compliance (PVC) were significantly impaired in ePH, preC-PH and postC-PH groups when compared to the normal group.

CONCLUSIONS

Both PH and ePH were highly prevalent within the IFLD patient group, suggesting that RHC should be offered more frequently in functionally limited patients. Diffusion capacity markers must thus guide decision making, in parallel to clinical evaluation. ePH was associated to lower resting CO and PVC, in a similar way to resting PH, indicating the relevance of cardiopulmonary function to exercise limitation. Finally, the use of the ΔPAWP/ΔCO>2 criterion further uncovered PH of postcapillary etiology, highlighting the complexity of hemodynamics in IFLD.

CLINICALTRIALS

gov ID: NCT03706820.

Alpha1-antitrypsin deficiency in Greece: Focus on rare variants

PURPOSE

A1Antitrypsin deficiency (AATD) pathogenic mutations are expanding beyond the PI*Z and PI*S to a multitude of rare variants.

AIM

to investigate genotype and clinical profile of Greeks with AATD.

METHODS

Symptomatic adult-patients with early-emphysema defined by fixed airway obstruction and computerized-tomography scan and lower than normal serum AAT levels were enrolled from reference centers all over Greece. Samples were analyzed in the AAT Laboratory, University of Marburg-Germany.

RESULTS

Included are 45 adults, 38 homozygous or compound heterozygous for pathogenic variants and 7 heterozygous. Homozygous were 57.9% male, 65.8% ever-smokers, median (IQR) age 49.0(42.5-58.5) years, AAT-levels 0.20(0.08-0.26) g/L, FEV1(%predicted) 41.5(28.8-64.5). PI*Z, PI*Q0, and rare deficient allele's frequency was 51.3%, 32.9%,15.8%, respectively. PI*ZZ genotype was 36.8%, PI*Q0Q0 21.1%, PI*MdeficientMdeficient 7.9%, PI*ZQ0 18.4%, PI*Q0Mdeficient 5.3% and PI*Zrare-deficient 10.5%. Genotyping by Luminex detected: p.(Pro393Leu) associated with MHeerlen (M1Ala/M1Val); p.(Leu65Pro) with MProcida; p.(Lys241Ter) with Q0Bellingham; p.(Leu377Phefs*24) with Q0Mattawa (M1Val) and Q0Ourem (M3); p.(Phe76del) with MMalton (M2), MPalermo (M1Val), MNichinan (V) and Q0LaPalma (S); p.(Asp280Val) with PLowell (M1Val); PDuarte (M4), YBarcelona (p.Pro39His). Gene-sequencing (46.7%) detected Q0GraniteFalls, Q0Saint-Etienne, Q0Amersfoort(M1Ala), MWürzburg, NHartfordcity and one novel-variant (c.1A>G) named Q0Attikon.Heterozygous included PI*MQ0Amersfoort(M1Ala), PI*MMProcida, PI*Mp.(Asp280Val), PI*MOFeyzin. AAT-levels were significantly different between genotypes (p = 0.002).

CONCLUSION

Genotyping AATD in Greece, a multiplicity of rare variants and a diversity of rare combinations, including unique ones were observed in two thirds of patients, expanding knowledge regarding European geographical trend in rare variants. Gene sequencing was necessary for genetic diagnosis. In the future the detection of rare genotypes may add to personalize preventive and therapeutic measures.

Isolated tuberculous arthritis of the ankle: a case report and review of the literature

BACKGROUND

Isolated ankle joint tuberculous arthritis is extremely rare, comprising an incidence lower than 5 % of skeletal tuberculosis (TB). Description of the case: We present an unusual case of isolated tubercular arthritis of the ankle in a 25-year-old male where the definitive diagnosis was difficult to be reached. The clinical examination revealed slight edema and a slight increase in local skin temperature. Based on magnetic resonance imaging performed, the diagnosis of septic arthritis was made. The arthroscopic appearance of the synovium and polymerase chain reaction analysis (PCR) of the synovial fluid revealed tuberculous arthritis.

CONCLUSION

TB should be included in the differential diagnosis of inflammatory arthritis in patients with persistent pain and swelling of the ankle. HIPPOKRATIA 2017, 21(2): 97-100.