Molecular testing for respiratory pathogens in sickle cell disease adult patients presenting with febrile acute chest syndrome

Abstract

Introduction. -Lors d'un épisode pulmonaire aigu fébrile chez un sujet drépanocytaire, il est parfois difficile de différencier un syndrome thoracique aigu (STA) d'une pneumopathie infectieuse (ressemblance sémiologique, absence fréquente de documentation microbiologique). Notre objectif était d'évaluer l'apport de la PCR pour détecter des pathogènes respiratoires, en association avec les examens microbiologiques standards, dans la documentation microbiologique des STA fébriles des patients drépanocytaires adultes. Matériels et méthodes. -Étude prospective, monocentrique et observationnelle réalisée de février 2015 à avril 2016. Des échantillons sanguins, respiratoires et urinaires ont été prélevés systématiquement avant et après antibiothérapie à des fins de cultures, antigénuries, sérologies et PCR pour détecter des pathogènes respiratoires.Résultats. -Un pathogène a été détecté dans 12 des 61 STA fébriles (19,7 %) : quatre virus (6,6 %) (Rhinovirus; Influenza A/B), sept bactéries (11,4 %) (S. aureus, S. pneumoniae, K. pneumoniae, L. pneumophila, M. pneumoniae), une co-infection (1,6 %) (S. aureus et Influenza B). La PCR a détecté une seule infection à L. pneumophila (sérogroupe 2). Si la durée d'antibiothérapie était significativement plus courte (6,1 vs 7,8 jours, p = 0,045) dans le groupe des STA sans documentation microbiologique, aucune autre différence n'a été mise en évidence entre le groupe des STA microbiologiquement documentés et de ceux non documentés.Conclusion. -Chez les patients drépanocytaires adultes, l'utilisation de la PCR à la recherche de pathogènes respiratoires améliore modérément le diagnostic microbiologique des STA fébriles, dans lesquels la part infectieuse est secondaire. AbstractBackground. -Differentiating acute chest syndrome (ACS) from community-acquired pneumonia (CAP) is challenging in adults presenting with major sickle cell disease (SCD) (semiological similarity, rare microbiological documentation). We aimed to assess the usefulness of nucleic ଝ Preliminary results presented at the 27th European Congress of Clinical Microbiology and Infectious Diseases, Vienna, Austria, April 22-25, 2017 (Poster abstract P0038).A. Raffetin et al. / Médecine et maladies infectieuses 50 (2020) [49][50][51][52][53][54][55][56] acid amplification test (NAAT) for respiratory pathogens, in combination with standard bacteriological investigations, in febrile ACS adult patients presenting with major SCD.Methods. -We performed a prospective, monocentric, observational study of 61 SCD adults presenting with febrile ACS from February 2015 to April 2016. Systematic blood, urine, and respiratory specimens were collected, before antibiotic initiation, for culture, urinary antigen tests, serology, and NAAT for respiratory pathogens.Results. -A pathogen was detected in 12 febrile ACS (19.7%): four viruses (6.6%) (Rhinovirus; Influenza A/B), seven bacteria (11.4%) (S. aureus, S. pneumoniae, K. pneumoniae, L. pneumophila, M. pneumoniae), one mixed infection (1.6%) (S. aureus and Influenza B). NAAT only detect...

Acute chest syndrome in adult patients with sickle cell disease: The relationship with the time to onset after hospital admission

“…However, our present findings are similar to those of a recent French study of 61 adult patients with SCD and febrile ACS; microbiological samples were collected in all cases, and pathogens were documented in 12 of these (19.7%). 33 Our findings are also consistent with other literature reports, in which the microbial positivity rate ranged from 1% to 25%. 13,24,34,35 Overall, the microbiological characteristics of ACS are poorly documented, even when systematic, in-depth microbiological work-up is performed.…”

“…Furthermore, our microbiological work‐up was guided by the patient's symptoms and was not systematic; hence, the positivity rate was probably overestimated. However, our present findings are similar to those of a recent French study of 61 adult patients with SCD and febrile ACS; microbiological samples were collected in all cases, and pathogens were documented in 12 of these (19.7%) 33 . Our findings are also consistent with other literature reports, in which the microbial positivity rate ranged from 1% to 25% 13,24,34,35 .…”

“…Indeed, in adult patients with SCD, antibiotic therapy should be restricted to febrile and/or severe episodes of ACS and should be fine-tuned as a function of the bacteria detected. 33 Moreover, and as emphasized by the glomerular hyperfiltration observed in our patients at the time of ACS (median [IQR] eGFR: 136 [127-146] mL/ min/1.73 m 2 ), elevated doses of antibiotic might be required to achieve a sufficient plasma concentration and thus avoid treatment failure. 36 Specific clinical and pharmacokinetic studies are therefore needed to determine how best to manage empirical antibiotic therapy and optimize the corresponding dosage regimens (especially for beta-lactams), as well as randomized studies to address a key question about the indication of antibiotics in afebrile ACS, or about the duration of antibiotics in febrile and non-severe ACS.…”

“…At the time of the first ACS episode, the median [IQR] age of the 81 patients was 27 [22][23][24][25][26][27][28][29][30][31][32][33][34] years (Table S1). There were 48 males (59%), and 72 patients (89%) had an S/S or S/ β 0 thalassaemia genotype.…”

“…In this study, we describe 105 consecutive ACS episodes in 81 adult patients during a 32-month period and compare the characteristics as a function of the time to onset after hospital admission for a vaso-occlusive crisis (VOC), that is early-onset episodes (time to onset ≤24 h, 42%) versus secondary episodes (>24 h, 58%; median [interquartile range] time to onset: 2 [2-3] days). The median age was 27 [22][23][24][25][26][27][28][29][30][31][32][33][34] years, 89% of the patients had an S/S or S/β 0 -thalassaemia genotype; 81% of the patients had a history of ACS (median: 3 [2-5] per patient), only 61% were taking a disease-modifying treatment at the time of the ACS. Fever and chest pain were noted in respectively 54% and 73% of the episodes.…”