Determinants of radiological patterns and severity in immunocompromised adults with Metapneumovirus infection

BACKGROUND

Human Metapneumovirus (HMPV) belongs to the Pneumoviridae family and is responsible for respiratory infections. Mild infections are well-recognized in children, while its precise impact in various categories of immunocompromised adults has not been well addressed.

RESEARCH QUESTION

We retrospectively studied HMPV infections in immunocompromised adults followed in two large French university medical centers.

STUDY DESIGN AND METHODS

We identified immunocompromised adults with positive HMPV Polymerase Chain Reaction (PCR) for 36 months and reviewed their medical charts. For lung transplant recipients (LTR), FEV1 was collected at baseline, during and after infection. Imaging was centralized and chest involvement was categorized by dominant CT patterns. We compared severe patients (requiring oxygen or ventilation) and non hypoxemic patients.

RESULTS

Seventy-two patients were included, 27 were LTR, 25 had a hematological malignancy or were hematopoietic stem cell recipients, 20 had another immunocompromised status. Twenty patients (28%) presented a hypoxemic infection, requiring hospitalization and intensive care units transfers in 50/72 (69.4%) and 9/72 (12.5%) respectively, with only one death. Hypoxemia was less pronounced in LTRs (p = 0.014). Finally, age and dyspnea remained independent factors associated with hypoxemia (p < 0.005). The most frequent radiological patterns were bronchopneumonia (34.2%) and bronchiolitis (39.5% and 64.3% in the overall population and in LTRs respectively, p = 0.045). FEV1 improved in LTRs at one month and 85% had recovered their baseline FEV1 within 6 months.

INTERPRETATIONS

In immunocompromised adults, HMPV infections required frequent hospitalizations and ICU transfers, while mortality is low. In LTRs, bronchiolitis pattern was predominant with short and long-term favorable outcome.

L’anosmie : critère spécifique de l’atteinte COVID-19 « Coranosmie1 »

Introduction

Depuis le mois d’avril, les publications médicales suggèrent que l’anosmie est un symptôme fréquent lors d’une infection liée au COVID-19. Notre objectif était de déterminer la valeur prédictive positive (VVP) et la spécificité (Sp) de l’anosmie et de décrire sa prévalence et ses caractéristiques chez les patients COVID-19.

Matériels et méthodes

Il s’agissait d’une étude prospective observationnelle longitudinale d’une cohorte multicentrique des patients consultants entre le 17 et le 24 mars 2020, pour anosmie depuis moins de 9 jours sans autres signes typiques d’infection à COVID-19. Les patients considérés comme COVID-19 positifs sont ceux ayant eu une RT-PCR COVID-19 positive sur les sécrétions nasopharyngées, ou ayant un contact documenté avec un patient COVID-19 positif. Sur 1824 patients, nous avons comparé la performance diagnostique de l’anosmie par rapport à celle des patients présentant une toux ou des céphalées. Comme pour l’anosmie, nous n’avons incus dans cette comparaison que les patients présentant des symptômes depuis moins de 9 jours.

Résultats

Parmi les 55 patients ayant consulté pour anosmie, 51 (IC92,7 % [82,4–97,9]) avait une RT-PCR positive. La charge virale était modérée pour les 51 patients avec un taux médian de CT à 28,83 (27,55–32,72). L’âge moyen des 55 patients était 35,7 ± 9,7 ans ; 56,4 % étaient des femmes. Dix-neuf patients (34,5 %) avaient des antécédents de rhinite allergique et 12 (21,8 %) étaient des fumeurs actifs. Aucun patient avait des antécédents de trouble de l’olfaction chronique. Une anosmie totale a été rapportée pour 47/55 patients (85,5 %) et une hyposmie pour 8 patients (14,5 %). L’anosmie était d’installation brutale dans 88,7 % des cas (n = 47/55) et associée à une dysgueusie dans 80 % des cas (n = 44/55). Une obstruction nasale était retrouvée chez seulement 2 patients. Les autres symptômes les plus fréquemment retrouvés étaient les céphalées (n = 37, 68,5 %), l’asthénie (n = 28, 57,1 %) et la toux (n = 22, 40,7 %). L’anosmie était inaugurale chez 16 patients (29,1 %). Pour les autres patients, elle a commencé 3 (2–4) jours après le début de l’infection. Aucun de nos patients a eu une évolution vers une forme grave. À j15, la majorité des patients (72,9 %) ont partiellement récupéré l’odorat. L’analyse effectuée sur 1824 avait démontré que la VVP (77,8 % [73,8–81,6]) de l’anosmie et sa Sp (90,2 %, [88,2–92,0]) étaient plus élevées que celles de la toux (VVP : 47,3 % [45,0–49,5], Sp : 34,3 % [32,2–36,4]) ou les céphalées (VVP : 47,9 % [45,7–50,1], Sp : 36,7 % [34,5–38,8]).

Conclusion

L’anosmie paraît un symptôme spécifique et a une VVP élevée par rapport aux autres symptômes classiques de l’infection COVID. Elle est dans la majorité des cas d’installation brutale, sans obstruction nasale, souvent associée à une dysgueusie, et d’évolution a priori favorable.

Agonist actions of dihydroergotamine at 5-HT2B and 5-HT2C receptors and their possible relevance to antimigraine efficacy

1. The pharmaceutical compound, dihydroergotamine (DHE) is dispensed to prevent and reduce the occurrence of migraine attacks. Although still controversial, the prophylactic effect of this drug is believed to be caused through blockade and/or activation of numerous receptors including serotonin (5-HT) receptors of the 5-HT2 subtype. 2. To elucidate if 5-HT2 receptors (5-HT2Rs) may be involved in DHE prophylactic effect, we performed investigations aimed to determine the respective pharmacological profile of DHE and of its major metabolite 8'-hydroxy-DHE (8'-OH-DHE) at the 5-HT2B and 5-HT2CRs by binding, inositol triphosphate (IP3) or cyclic GMP (cGMP) coupling studies in transfected fibroblasts. 3. DHE and 8'-OH-DHE are competitive compounds at 5-HT2B and 5-HT2CRs. 8'-OH-DHE interaction at (5-HT2BRs) was best fitted by a biphasic competition curve and displayed the highest affinity with a Ki of 5 nm. These two compounds acted as agonists for both receptors in respect to cGMP production with pEC50 of 8.32+/-0.09 for 8'-OH-DHE at 5-HT2B and 7.83+/-0.06 at 5-HT2CRs. 4. Knowing that the antimigraine prophylactic effect of DHE is only observed after long-term treatment, we chronically exposed the recombinant cells to DHE and 8'-OH-DHE. The number of 5-HT2BR-binding sites was always more affected than 5-HT2CRs. At 5-HT2BRs, 8'-OH-DHE was more effective than DHE, with an uncoupling that persisted for more than 40 h for IP3 or cGMP. By contrast, the 5-HT2CR coupling was reversible after either treatment. 5. Chronic exposure to 8'-OH-DHE caused a persistent agonist-mediated desensitisation of 5-HT2B, but not 5-HT2CRs. This may be of relevance to therapeutic actions of the compound.

Function of the serotonin 5-hydroxytryptamine 2B receptor in pulmonary hypertension

Primary pulmonary hypertension is a progressive and often fatal disorder in humans that results from an increase in pulmonary blood pressure associated with abnormal vascular proliferation. Dexfenfluramine increases the risk of pulmonary hypertension in humans, and its active metabolite is a selective serotonin 5-hydroxytryptamine 2B (5-HT(2B)) receptor agonist. Thus, we investigated the contribution of the 5-HT(2B)receptor to the pathogenesis of pulmonary hypertension. Using the chronic-hypoxic-mouse model of pulmonary hypertension, we found that the hypoxia-dependent increase in pulmonary blood pressure and lung remodeling are associated with an increase in vascular proliferation, elastase activity and transforming growth factor-beta levels, and that these parameters are potentiated by dexfenfluramine treatment. In contrast, hypoxic mice with genetically or pharmacologically inactive 5-HT(2B)receptors manifested no change in any of these parameters. In both humans and mice, pulmonary hypertension is associated with a substantial increase in 5-HT(2B) receptor expression in pulmonary arteries. These data show that activation of 5-HT(2B) receptors is a limiting step in the development of pulmonary hypertension.

Developmentally regulated serotonin 5-HT2B receptors

Serotonin (5-hydroxytryptamine, 5-HT) binds to numerous cognate receptors to initiate its biological effects. In this review, we have focused on the 5-HT2B receptor to address how signaling and expression of this receptor is specifically implicated in embryonic development and adult health and disease. Transduction of the 5-HT2B signaling is complex, including phospholipase C and A2 stimulation, cGMP production and a mitogenic signal that integrates the tyrosine kinase-signaling pathway. Furthermore, 5-HT, through the 5-HT2B receptors, has the ability to control serotonergic differentiation of committed neuron-like cells. In addition, 5-HT2B receptors are actively involved in the transient action of 5-HT during embryonic morphogenesis. Our recent data presented the first genetic evidence that 5-HT via 5-HT2B receptors regulates cardiac embryonic development and adult functions and suggested that this receptor subtype may be involved in other physiopathological situations. In particular, 5-HT-dependent molecular mechanisms may be involved in embryonic development and postnatal maturation of the enteric nervous system. Also, the involvement of the 5-HT2B receptor in the vascular growth often observed in hypertension is likely. These probably result from reactivation of developmentally regulated receptors in pathological situations. Finally, embryonic functions of 5-HT2 receptors observed in Drosophila gastrulation suggest evolutionary conserved mechanisms.

Evaluation of the effect of a fiber-enriched formula on infant colic

Because infants with colic appear to have abdominal pain similar to that of adults with irritable bowel syndrome, who may benefit from the addition of fiber to their diet, we tested whether fiber added to infant formula would alleviate colic. Twenty-seven normal, term infants (aged 2 to 8 weeks; 14 girls) with colic, defined as crying plus fussing for more than 3 hours a day for at least 3 days of a 6-day baseline period, were enrolled. Infants were randomly assigned in 9-day periods to a sequence of placebo (Isomil formula) followed by fiber-supplemented formula (Isomil plus soy polysaccharide) (n = 12) or the reverse (n = 15). Daily diaries of crying, fussing, sleeping, formula, intake, and stooling were kept. Twenty-two infants completed three lactulose breath hydrogen tests at the end of the baseline period and after each study period. The crossover trial was followed by 30 to 35 days of use of the study formula chosen by the parents as most beneficial but unknown to the investigators. Growth was monitored throughout. Serum cholesterol, calcium, phosphate, albumin, iron, and zinc concentrations were measured at the conclusion. There were no significant differences in average daily time spent by the infants in fussing and crying during ingestion of the fiber-supplemented formula. However, parents of 18 of 27 infants chose fiber-supplemented formula as most beneficial in ameliorating symptoms of colic. While the infants were consuming fiber-supplemented formula, stool frequency increased, and breath hydrogen excretion increased significantly, in response to lactulose. Growth and serum biochemical measurements were normal in all infants. Supplementation of infant formula with the level of soy polysaccharide used in this study may have reduced crying and fussing in some infants but did not affect colicky behavior in the majority of infants, who continued to cry and fuss excessively.

Pancreatitis following scoliosis surgery in children and young adults

Forty-four patients undergoing single-stage surgery for scoliosis were monitored for biochemical and clinical evidence of pancreatitis. Six patients (14%) developed elevation of both serum amylase and lipase levels. Four of these had symptoms or signs suggestive of pancreatitis. Mean intraoperative blood loss was significantly higher in the group with pancreatitis. No significant differences were noted with regard to age, surgical technique, degree of initial or residual deformity, or length of surgery. The patients with pancreatitis required a longer average period of fasting time. Patients with prolonged ileus or abdominal pain after scoliosis surgery should be investigated for possible pancreatitis.

Olfactory identification deficits in HIV infection

OBJECTIVE

Impaired odor identification is described in a number of CNS disorders, and human immunodeficiency virus (HIV) infects the CNS in a large percentage of patients. To evaluate whether impaired olfaction may indicate CNS disease, the authors measured odor identification in patient groups defined along a continuum of progressive immunodeficiency and in a comparison group.

METHOD

Most of the 42 HIV-infected patients in the study were outpatients in a clinic specializing in treatment of HIV-infected individuals. The comparison subjects were 37 healthy age- and sex-matched individuals who were recruited from hospital and medical school personnel. Ten of the patients were HIV-seropositive but had no symptoms, 24 had clinical evidence of immunocompromise, and eight had HIV dementia. All subjects were given the University of Pennsylvania Smell Identification Test, which presents common odorants and requires the subject to identify the odor from a four-item word list. The data were analyzed by using analysis of variance after arc-sine transformation and Scheffé post hoc analysis.

RESULTS

All patients scored significantly lower on the Smell Identification Test than did the comparison subjects. The patients with HIV dementia had significantly lower scores than did the other two groups of patients.

CONCLUSIONS

Clinically, impaired olfaction might serve as a marker of early CNS HIV involvement. Future studies should attempt to match comparison and experimental populations for socioeconomic status and HIV risk behavior.

[Cardiac surgery in Jehovah's witnesses. Apropos of 47 cases]

47 cardiac defects in Jehova's witnesses were operated on without using any blood during the operation. In 9 cases the patients were under 15 years of age. 7 cases were of congenital heart defects in which the operation could be carried out with the heart still beating or by a closed heart technique: 4 of these were adults and 3 were children. In 40 cases, extracorporeal circulation was required: 19 valve defects, 8 coronary areterial cases, 10 congenital cardiac lesions, 2 valve defects associated with coronary artery disease, and 1 aneurysm of the thoracic aorta. Of these 40 patients, 4 died. The details and limits of this total haemodilution are analysed, as are the causes of failure and complications. This technique does not worsen the postoperative prognosis appreciably, but limits the scope of the surgery, and cannot be applied to a child of less than 10 kg.