Background: The Centers for Disease Control and Prevention advises that patients with moderate to severe asthma belong to a high-risk group that is susceptible to severe coronavirus disease 2019 (COVID-19). However, the association between asthma and COVID-19 has not been well-established. Objective: The primary objective was to determine the prevalence of asthma among patients with COVID-19 in a major US health system. We assessed the clinical characteristics and comorbidities in asthmatic and nonasthmatic patients with COVID-19. We also determined the risk of hospitalization associated with asthma and/or inhaled corticosteroid use. Methods: Medical records of patients with COVID-19 were searched by a computer algorithm (March 1 to April 15, 2020), and chart review was used to validate the diagnosis of asthma and medications prescribed for asthma. All patients had PCRconfirmed COVID-19. Demographic and clinical features were characterized. Regression models were used to assess the associations between asthma and corticosteroid use and the risk of COVID-19-related hospitalization. Results: Of 1526 patients identified with COVID-19, 220 (14%) were classified as having asthma. Asthma was not associated with an increased risk of hospitalization (relative risk, 0.96; 95% CI, 0.77-1.19) after adjusting for age, sex, and comorbidities. The ongoing use of inhaled corticosteroids did not increase the risk of hospitalization in a similar adjusted model (relative risk, 1.39; 95% CI, 0.90-2.15). Conclusions: Despite a substantial prevalence of asthma in our COVID-19 cohort, asthma was not associated with an increased risk of hospitalization. Similarly, the use of inhaled corticosteroids with or without systemic corticosteroids was not associated with COVID-19-related hospitalization. (J Allergy Clin Immunol 2020;146:307-14.)

SUMMARY The frequency of HLA antigens was studied in 25 patients with primary sclerosing cholangitis and compared with a control group of 561 kidney donors. Fourteen patients also had ulcerative colitis. A significant increase in the frequency of HLA-B8 (60%) was found in the primary sclerosing cholangitis patients compared with controls (25%) (p<0-001). HLA-B8 was found in eight patients with ulcerative colitis. The frequency of HLA-B12 was significantly decreased (8%) compared with controls (30%) (p<0-02). Piecemeal necrosis was observed on liver histology in 66% of HLA-B8 positive and 50% of HLA-B8 negative patients. Low titres of serum autoantibodies were frequently found in the primary sclerosing cholangitis group but did not correspond to the presence of HLA-B8. Raised serum concentrations of IgM and IgG were not related to HLA-B8. This study has shown that in patients with primary sclerosing cholangitis there exists a disease susceptibility gene closely associated with the B locus of the major histocompatibility complex which may be modified by other factors such as ulcerative colitis. Patients with ulcerative colitis and HLA-B8 may be particularly liable to develop primary sclerosing cholangitis.Primary sclerosing cholangitis is an uncommon disease characterised by an intense inflammatory fibrosis usually involving the whole biliary system.'The aetiology of this disorder is unknown, although it is closely associated with ulcerative colitis which coexists in approximately two-thirds of patients with primary sclerosing cholangitis.'The associations between certain human leucocyte histocompatibility (HLA) antigens and an increased risk of certain diseases have recently been identified. HLA-B8 and HLA-DRW3, for example, have been closely associated with diseases involving immunological dysfunction such as autoimmune chronic active hepatitis.2 HLA-A3 has been closely associated with idiopathic haemochromatosis.3The purpose of the present study was to investigate possible associations between the HLA system and patients with primary sclerosing cholangitis, with and without coexisting ulcerative colitis. ' Address for correspondence: Dr R W Chapman, John Radcliffe Hospital, Headington, Oxford. Received for publication 13 April 1982 Methods PATIENTS Twenty-five consecutive patients (17 men and eight women) with primary sclerosing cholangitis who were admitted to the Royal Free Hospital for investigation were studied. The diagnosis was based on accepted criteria -namely, the demonstration of multiple strictures in the biliary system, the absence of previous biliary tract surgery, and the exclusion of bile duct cancer by at least two years' follow-up

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Hereditary angioedema (HAE) is an autosomal dominant disorder defined by a deficiency of functional C1 esterase inhibitor (C1-INH). Acquired angioedema is due to either consumption (type 1) or inactivation (type 2) of CI-INH. Both HAE and acquired angioedema can be life-threatening. Of the three types of HAE, type 1 is most common, occurring in approximately 85% of patients and characterized by decreased production of C1-INH, which results in reduced functional activity to 5‐40% of normal. Type 2 occurs in 15% of cases; C1-INH is detectable in normal or elevated quantities but is dysfunctional. Also, HAE with normal CI-INH (previously called type 3 HAE) is rare and characterized by normal complement studies. Specific genetic mutations have been linked to factor XII, angiopoietin-1, and plasminogen gene. Patients with unknown mutations are classified as unknown. The screening test for types 1 and 2 is complement component C4, which is low to absent at times of angioedema and during quiescent periods. A useful test to differentiate HAE from acquired angioedema is C1q protein, which is normal in HAE and low in acquired angioedema. The management of HAE has been transformed with the advent of disease-specific therapies. On-demand therapy options include plasma and recombinant C1-INH for intravenous infusion; ecallantide, an inhibitor of kallikrein; and icatibant, a bradykinin β2 receptor antagonist, both administered subcutaneously. For long-term prophylaxis, intravenous or subcutaneous C1-INH enzyme replacement and lanadelumab, a monoclonal antibody against kallikrein that is administered subcutaneously, are effective agents.

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