Positron Emission Tomography With 18F-Fluorodeoxyglucose in Patients With Sickle Cell Acute Chest Syndrome

Abstract

The acute chest syndrome (ACS) is the main cause of mortality among adult patients with sickle cell disease (SCD). Its pathophysiology is still unclear. Using positron emission tomography (PET) with 18F-fluorodeoxyglucose [18F-fluorodeoxyglucose (18F-FDG)], we explored the relationship between regional lung density and lung metabolism, as a reflection of lung neutrophilic infiltration during ACS.Patients were prospectively enrolled in a single-center study. Dual modality chest PET/computed tomography (CT) scans were performed, with 18F-FDG emission scans for quantification of regional 18F-FDG uptake and CT scans with radiocontrast agent to check for pulmonary artery thrombosis. Regional lung 18F-FDG uptake was quantified in ACS patients and in SCD patients without ACS (SCD non-ACS controls). Maximal (SUVmax) and mean (SUVmean) standardized uptake values were computed.Seventeen patients with ACS (mean age 28.3 ± 6.4 years) were included. None died nor required invasive mechanical ventilation. The main lung opacity on CT scans was lower lobe consolidation. Lungs of patients with ACS exhibited higher SUVmax than those of SCD non-ACS controls (2.5 [2.1–2.9] vs 0.8 [0.6–1.0]; P < 0.0001). Regional SUVmax and SUVmean was higher in lower than in upper lobes of ACS patients (P < 0.001) with a significant correlation between lung density and SUVmax (R2 = 0.78). SUVmean was higher in upper lobes of ACS patients than in lungs of SCD non-ACS controls (P < 0.001). Patients with SUVmax >2.5 had longer intensive care unit (ICU) stay than others (7 [6–11] vs 4 [3–6] days; P = 0.016).Lungs of patients with ACS exhibited higher 18F-FDG uptake than SCD non-ACS controls. Lung apices had normal aeration and lower 18F-FDG uptake than lung bases, but higher 18F-FDG uptake than lungs of SCD non-ACS controls. Patients with higher lung 18F-FDG uptake had longer ICU stay than others.

Morpho-functional evaluation of lung aeration as a marker of sickle-cell acute chest syndrome severity in the ICU: a prospective cohort study

“…In our study, the main ACS morphological pattern was large bilateral lung consolidations, predominantly distributed in dependent pulmonary areas. Our results are concordant with previous CT-scan reports [9, 14, 21] and with the only other study that used LU in ACS patients admitted to the ICU [22]. Lungs of ACS patients showed a dramatic loss of aeration leading to severe impairment of vital capacity and high initial LUS.…”

“…Complicated outcome was defined a priori according to previously published criteria, by occurrence of at least one of the following events: ≥ 3 red blood cell (RBC) units transfused during ICU stay [3, 9, 14]; invasive or non-invasive mechanical ventilation requirement [3, 5, 9]; ICU length-of-stay > 5 days [3, 14, 15]; or in-hospital death.…”

IL-6 levels are dramatically high in the sputum from children with sickle cell disease during acute chest syndrome

“…Figure 1A). By contrast, median IL-6 level in sputum was dramatically elevated during ACS (3320 [1233-6459] pg/mL) compared with non-ACS patients (13 [11][12][13][14][15][16][17][18][19] pg/mL; P 5 .0009; Figure 1B). For the 5 patients who had concomitant sputum and plasma collections during ACS, median IL-6 level was .150-fold higher in sputum (6892 [6314-7114] pg/mL) than in plasma (42 [35-48] pg/mL; P 5 .0009; Figure 1C).…”

“…Moreover, reported levels of IL-6 in endotracheal fluid from non-SCD children with severe pneumonia requiring mechanical ventilation are much lower than those observed in our patients. 16 Sputum levels of IL-8, CCL2, and CCL3 chemokines are high during ACS Figure 1I), and CCL3 (62 [32-105] pg/mL vs 12 [9][10][11][12][13][14][15][16][17][18][19] pg/mL; P 5 .01; Figure 1J). These high chemokine levels could induce pulmonary recruitment of innate immune cells, including neutrophils and monocytes, which in turn may produce inflammatory mediators, thus contributing to a vicious cycle of local inflammation during ACS.…”

A diagnostic nomogram for delayed hemolytic transfusion reaction in sickle cell disease

“…Its potential benefits include correction of anemia, reduction of hemolysis, suppression of HbS synthesis, and decrease in the percentage of circulating sickle cells . The efficacy of RBC transfusion may be influenced by the recipient's inflammatory state , the latter being a characteristic feature of acute complications of SCD .…”