key: cord-025380-6bagohw8
authors: Navel, Valentin; Chiambaretta, Frédéric; Dutheil, Frédéric
title: Reply
date: 2020-05-28
journal: J Allergy Clin Immunol
DOI: 10.1016/j.jaci.2020.05.010
sha: 
doc_id: 25380
cord_uid: 6bagohw8

nan

parts of China with continental rainy-cold climates. These provinces are particularly industrialized with considerable pollution in cities, ensuring populations are heavily exposed to particulate matter (PM), ozone (O 3 ), carbon dioxide (CO 2 ), nitrogen dioxide (NO 2 ), and sulfur dioxide (SO 2 ) produced by diesel combustion. Similar to Italy and China, the North-eastern population of France is more affected by COVID-19 than the population of the Atlantic coast and Mediterranean regions. 3, 4 Similar to the Italian peninsula, France could be isolated into 2 macro-area zones on both sides of the river Loire, highlighting a clear North-West/ South-East line coinciding with the French Demarcation line during World War II (Fig 1 [F1-4/C] ). The populations living next to coasts with daily exposure to oceanic or Mediterranean climates seem to be less at risk of COVID-19. However, the putative link between COVID-19 and geographic zones could be associated with genetic variations in the population and explained by the 1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  18  19  20  21  22  23  24  25  26  27  28  29  30  31  32  33  34  35  36  37  38  39  40  41  42  43  44  45  46  47  48  49  50  51  52  53  54  55  56  57  58  59  60   61  62  63  64  65  66  67  68  69  70  71  72  73  74   75  76  77  78  79  80  81  82  83  84  85  86  87  88  89  90  91  92  93  94  95  96  97  98  99  100  101  102  103  104  105  106  107  108  109  110  111  112  113  114  115  116  117  118  119 importance of human exchanges around continental frontiers areas (eg, North-eastern part of France, BENELUX countries, and urban area of Ruhr). Similar to the environmental exposures affecting the incidence and decompensation of allergic diseases, COVID-19 could be affected by internal and external exposome. 5 In crowded areas and industrialized territories exposed to hot warm season, the high levels of O 3 seem to be associated with variations in epigenetic modulation. Globally, emerging data may identify air pollution as a modulator to DNA methylation (DNAm) disturbing the inflammation process, allergic diseases development, and exacerbation risk. 6 As such, NO 2 and PM exposures during pregnancy could significantly deregulate DNAm of antioxidants or anti-inflammatory genes related to the oxidative stress pathway in utero. 7, 8 Interestingly, lower DNAm of IL-6 and IFN-g genes was identified in adults exposed to PM, black carbon, and O 3 , involving an increase in specific immune system. 9 The change in DNAm was often observed at specific locations within the promoter region, deregulating the expression of genetic heritage. Considering that SARS-CoV-2 infection involves a proinflammatory cytokine storm as IL-6 and IL-1b, a putative hypothesis could explain that populations exposed to chronic air pollution are associated with a different COVID-19 incidence in line with chronic epigenetic deregulation. Affecting the immune system and the inflammatory pathways, DNAm related to air pollution could explain the disparities in COVID-19 in geographic zones in which genetically predisposed populations were living in climate favoring SARS-CoV-2 distribution. 120  121  122  123  124  125  126  127  128  129  130  131  132  133  134  135  136  137  138  139  140  141  142  143  144  145  146  147  148  149  150  151  152  153  154  155  156  157  158  159  160  161  162  163  164  165  166  167  168  169  170  171  172  173  174  175  176  177  178  179  180 

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Will environmental impacts of social distancing due to the SARS-CoV-2 pandemic decrease allergic disease?

Minist ere des Solidarit es et de la Sant e. Epidemiologic situation of SARS-CoV-2 in France

A cross-sectional comparison of epidemiological and clinical features of patients with coronavirus disease (COVID-19) in Wuhan and outside Wuhan, China

Climate change and outdoor aeroallergens related to allergy and asthma: taking the exposome into account

Air pollution and DNA methylation: effects of exposure in humans

Air pollution during pregnancy and placental adaptation in the levels of global DNA methylation

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Air pollution and gene-specific methylation in the Normative Aging Study: association, effect modification, and mediation analysis