Assessment and validation of enrichment and target capture approaches to improve Mycobacterium tuberculosis WGS from direct patient samples.

Within-host Mycobacterium tuberculosis (Mtb) diversity may detect antibiotic resistance or predict tuberculosis treatment failure and is best captured through sequencing directly from sputum. Here, we compared three sample pre-processing steps for DNA decontamination and studied the yield of a new target enrichment protocol for optimal whole-genome sequencing (WGS) from direct patient samples. Mtb-positive NALC-NaOH-treated patient sputum sediments were pooled, and heat inactivated, split in replicates, and treated by either a wash, DNase I, or benzonase digestion. Levels of contaminating host DNA and target Mtb DNA were assessed by quantitative PCR (qPCR), followed by WGS with and without custom dsDNA target enrichment. The pre-treatment sample has a high host-to-target ratio of DNA (6,168 ± 1,638 host copies/ng to 212.3 ± 59.4 Mtb copies/ng) that significantly decreased with all three treatments. Benzonase treatment resulted in the highest enrichment of Mtb DNA at 100-fold compared with control (3,422 ± 2,162 host copies/ng to 11,721 ± 7,096 Mtb copies/ng). The custom dsDNA probe panel successfully enriched libraries from as little as 0.45 pg of Mtb DNA (100 genome copies). Applied to direct sputum the dsDNA target enrichment panel increased the percent of sequencing reads mapping to the Mtb target for all three pre-processing methods. Comparing the results of the benzonase sample sequenced both with and without enrichment, the percent of sequencing reads mapping to the Mtb increased to 90.95% from 1.18%. We demonstrate a low limit of detection for a new custom dsDNA Mtb target enrichment panel that has a favorable cost profile. The results also demonstrate that pre-processing to remove contaminating extracellular DNA prior to cell lysis and DNA extraction improves the host-to-Mtb DNA ratio but is not adequate to support average coverage WGS without target capture.

Smoked drug use in patients with TB is associated with higher bacterial burden.

BACKGROUND: Smoking of illicit drugs may lead to more rapid TB disease progression or late treatment presentation, yet research on this topic is scant. We examined the association between smoked drug use and bacterial burden among patients newly initiated on drug-susceptible TB (DS-TB) therapy.METHODS: Data from 303 participants initiating DS-TB treatment in the Western Cape Province, South Africa, were analyzed. Smoked drug use was defined as self-reported or biologically verified methamphetamine, methaqualone and/or cannabis use. Proportional hazard and logistic regression models (adjusted for age, sex, HIV status and tobacco use) examined associations between smoked drug use and mycobacterial time to culture positivity (TTP), acid-fast bacilli sputum smear positivity and lung cavitation.RESULTS: People who smoked drugs (PWSD) comprised 54.8% (n = 166) of the cohort. TTP was faster for PWSD (hazard ratio 1.48, 95% CI 1.10-1.97; P = 0.008). Smear positivity was higher among PWSD (OR 2.28, 95% CI 1.22-4.34; P = 0.011). Smoked drug use (OR 1.08, 95% CI 0.62-1.87; P = 0.799) was not associated with increased cavitation.CONCLUSIONS: PWSD had a higher bacterial burden at diagnosis than those who do not smoke drugs. Screening for TB among PWSD in the community may facilitate earlier linkage to TB treatment and reduce community transmission.

The Phenotypic Spectrum of New-onset IBD in Canadian Children of South Asian Ethnicity: A Prospective Multi-Centre Comparative Study.

BACKGROUND: Canadian-born children of South Asian [SA] ethnicity develop inflammatory bowel disease [IBD] at similar rates to those among Caucasian children. We evaluated the variation in phenotypic spectrum of IBD in SA and Caucasian children in a national paediatric inception cohort of new-onset IBD. METHODS: Patients aged <17 years, enrolled in a Canadian nationwide inception cohort study, were included. Baseline demographic and IBD phenotypic features were compared between SA and Caucasian children. Longitudinal outcomes through 18 months of follow-up were compared matched by propensity scores. RESULTS: Of 1156 children enrolled over 2014 to 2019, 623 were Caucasian [98% and 88% parents Canadian born] and 114 SA [79% Canadian born, 87% parents SA born]. Fewer SAs have a first-degree relative with IBD, 6% vs 19% in Caucasians, p = 0.002. SAs present at a younger age, median age 11.4 years (interquartile range [IQR] 9.2-14.3) vs 13 years [IQR 10.9-15 years], p = 0.03 and more commonly with a UC/IBD-U [ulcerative colitis/IBD-unclassified] subtype [ratio of UC/IBD-U to CD 1.2:1 vs 1:1.8 for Caucasians, p <0.001]. Additionally, a greater proportion of SA CD patients present with colonic-only disease [colonic-only CD/UC/IBD-U in SAs 67% vs 57% for Caucasians, p = 0.001], and among those with CD, colonic CD in SAs 31% vs 23% in Caucasians, p = 0.20]. Perianal fistulising disease was also numerically more common in SAs (14 [27%] vs 64 [18%], p = 0.06]. Adjusting for differences in phenotypic presentation, anti-tumour necrosis factor [TNF] exposure, and time to initiation was similar, and two-thirds of children, whether anti-TNF exposed or naïve, were in corticosteroid-free clinical remission at 18 months irrespective of ethnicity. CONCLUSIONS: The phenotypic spectrum of new-onset IBD in SA children differs from that of Caucasian children, but treatment and clinical course are similar within phenotypic subgroups.

The impact of alcohol use on tuberculosis treatment outcomes: a systematic review and meta-analysis.

Alcohol use is associated with increased risk of developing tuberculosis (TB) disease, yet the impact of alcohol use on TB treatment outcomes has not been summarized. We aimed to quantitatively review evidence of the relationship between alcohol use and poor TB treatment outcomes. We conducted a systematic review of PubMed, EMBASE, and Web of Science (January 1980-May 2018). We categorized studies as having a high- or low-quality alcohol use definition and examined poor treatment outcomes individually and as two aggregated definitions (i.e., including or excluding loss to follow-up [LTFU]). We analyzed drug-susceptible (DS-) and multidrug-resistant (MDR-) TB studies separately. Our systematic review yielded 111 studies reporting alcohol use as a predictor of DS- and MDR-TB treatment outcomes. Alcohol use was associated with increased odds of poor treatment outcomes (i.e., death, treatment failure, and LTFU) in DS (OR 1.99, 95% CI 1.57-2.51) and MDR-TB studies (OR 2.00, 95% CI 1.73-2.32). This association persisted for aggregated poor treatment outcomes excluding LTFU, each individual poor outcome, and across sub-group and sensitivity analyses. Only 19% of studies used high-quality alcohol definitions. Alcohol use significantly increased the risk of poor treatment outcomes in both DS- and MDR-TB patients. This study highlights the need for improved assessment of alcohol use in TB outcomes research and potentially modified treatment guidelines for TB patients who consume alcohol.

Phenotypic Variation in Paediatric Inflammatory Bowel Disease by Age: A Multicentre Prospective Inception Cohort Study of the Canadian Children IBD Network.

BACKGROUND AND AIMS: Incidence of paediatric inflammatory bowel disease [IBD] in Canada is among the highest worldwide, and age of onset may be decreasing. In a multicentre nationwide inception cohort study, we examined variation in phenotype of IBD throughout the paediatric age spectrum. METHODS: Children aged ≥2 years [y] and <17y [A1 age at diagnosis], with new onset IBD, were systematically evaluated at sites of the Canadian Children IBD Network. Prospectively recorded phenotypic data were compared between age groups. RESULTS: Among 1092 children (70% Caucasian; 64% Crohn's disease [CD], 36% ulcerative colitis/inflammatory bowel disease unclassified [UC/IBD-U]; median age 13 y, interquartile range [IQR] 11-15 y), 210 [19%] were diagnosed before the age of age 10 y [Paris A1a] and 43 [4%] before age 6 y (very-early-onset [VEO-IBD]). CD was less common in younger children [42%, 56%, 66%, respectively, of VEO-IBD, A1a; A1b]. Colon-only IBD [UC/IBDU or CD-colon] was present in 81% of VEO-IBD and 65% of A1a; ileal disease increased progressively, reaching plateau at age 10 y. CD location was ileocolonic [L3] in 53% overall. Ileitis [L1] increased with age [6% of VEO-IBD; 13% of A1a; 21% of A1b], as did stricturing/penetrating CD [4% of A1a; 11% of A1b]. At all ages UC was extensive [E3/E4] in >85%, and disease activity moderate to severe according to Physician's Global Assessment [PGA] and weighted Paediatric Crohn's Disease Activity Index/Paediatric Ulcerative Colitis Activity Index [wPCDAI/PUCAI] in >70%. Heights were modestly reduced in CD [mean height z score -0.30 ± 1.23], but normal in UC/IBD-U. CONCLUSIONS: Paris classification of age at diagnosis is supported by age-related increases in ileal disease until age 10 years. Other phenotypic features, including severity, are similar across all ages. Linear growth is less impaired in CD than in historical cohorts, reflecting earlier diagnosis.

Overcoming limitations of tuberculosis information systems: researcher and clinician perspectives.

SETTING: Tuberculosis (TB) diagnosis and treatment requires patients to have multiple encounters with health care systems and the different stakeholders who play a role in curing them to coordinate their efforts. To optimize this process, high-quality, readily available data are required. Data systems to facilitate these linkages are a neglected priority which, if weak, fundamentally undermine TB control interventions. OBJECTIVE: To describe lessons learnt from the use of programmatic data for TB patient care and research. DESIGN: We did a survey of researcher and clinical provider experiences with information systems and developed a tiered approach to addressing frequently reported barriers to high-quality care. RESULTS: Unreliable linkages, incomplete data, lack of a reliable unique patient identifier, and lack of data management expertise were the most important data-related barriers to high-quality patient care and research. We propose the creation of health service delivery environments that facilitate, prioritize, and evaluate high-quality data entry during patient or specimen registration. CONCLUSION: An integrated approach, focused on high-quality data, and centered on unique patient identification will form the foundation for linkages across health systems that reduce patient management errors, bolster surveillance, and enhance the quality of research based on programmatic data.

Discordant rifampicin susceptibility results are associated with Xpert® MTB/RIF probe B and probe binding delay.

SETTING: Xpert® MTB/RIF is the first-line diagnostic test for Mycobacterium tuberculosis and rifampicin (RIF) resistance in South Africa. OBJECTIVE: To describe the rates of Xpert RIF resistance not confirmed on follow-up testing, as well as the patient and test characteristics associated with discordant results. DESIGN: Retrospective review of patients with isolates showing Xpert RIF resistance. Line-probe assay, phenotypic drug susceptibility testing or repeat Xpert were all considered confirmatory tests of RIF resistance. 'Discordance' was defined as a patient with RIF resistance identified on initial Xpert testing, with a subsequent confirmatory test indicating RIF susceptibility. Associations were analysed using Pearson χ² difference of proportions and modified Poisson regression. RESULTS: RIF discordance occurred in 22/263 subjects and was associated with Xpert probe B, probe binding delay, as opposed to probe dropout, and probe binding delays (ΔCt) of between 4 and 4.9. CONCLUSION: Discordant RIF resistance was common in our cohort and was associated with Xpert probe delay and use of probe B.

Can patients afford the cost of treatment for multidrug-resistant tuberculosis in Ethiopia?

SETTING: Ethiopia has a high prevalence of tuberculosis (TB) and is one of the countries with the highest burden of multidrug-resistant TB (MDR-TB). OBJECTIVE: To understand the costs that patients incur in obtaining diagnosis and treatment for MDR-TB. DESIGN: In March 2013, interviews were conducted with 169 MDR-TB patients at three hospitals in Ethiopia to identify the cost to patients and the impact on employment and family income. RESULTS: The average MDR-TB patient incurred a total cost of US$1378, which represented 25 months of a mid-treatment household income of US$54. The impact on the patient's employment and on overall patient and family income was generally catastrophic: 74% of all respondents reported losing their jobs, 66% of patients lost household income, and household income was reduced by 38%. To help cover the costs, 38% of patients sold some type of property, while 7% leased out property and 41% took out loans, any of which could jeopardize their future financial situation even further. CONCLUSION: Despite services being officially free of charge, most patients incurred catastrophic costs and suffered significant income loss as a result of obtaining diagnosis and treatment for MDR-TB.

Dietary patterns and risk of ulcerative colitis: a case-control study.

BACKGROUND: Recent evidence indicates a role for dietary factors in the pathogenesis of ulcerative colitis (UC). The aim of the present study was to investigate the relationship between dietary patterns and UC risk. METHODS: Sixty-two newly diagnosed cases of UC and 124 healthy age and sex-matched controls were studied. Data on diet was measured using a validated country-specific food frequency questionnaire. Factor analysis was used to define major dietary patterns based on 28 food groups and nutrient content. RESULTS: After adjustment for confounding factors, subjects who were in the highest tertile of the healthy dietary pattern had a 79% lower risk of UC (odds ratio = 0.21, 95% confidence interval = 0.07-0.59, P = 0.003), whereas the consumption of an unhealthy dietary pattern was associated with a significantly increased risk of UC (odds ratio = 3.39, 95% 95% confidence interval = 1.16-9.90, P = 0.027). CONCLUSIONS: The findings of the present study suggest that dietary patterns are associated with UC risk.

The goblet cell-derived mediator RELM-ß drives spontaneous colitis in Muc2-deficient mice by promoting commensal microbial dysbiosis.

Intestinal goblet cells are potentially key players in controlling susceptibility to ulcerative colitis (UC). Although impaired mucin (Muc2) production by goblet cells increases microbial stimulation of the colonic mucosa, goblet cells secrete other mediators that may influence or promote UC development. Correspondingly, Muc2-deficient ((-/-)) mice develop spontaneous colitis, concurrent with the dramatic upregulation of the goblet cell mediator, resistin-like molecule-beta (RELM-ß). Testing RELM-ß's role, we generated Muc2(-/-)/Retnlb(-/-) mice, finding that RELM-ß deficiency significantly attenuated colitis development and symptoms compared with Muc2(-/-) mice. RELM-ß expression in Muc2(-/-) mice strongly induced the production/secretion of the antimicrobial lectin RegIIIß, that exerted its microbicidal effect predominantly on Gram-positive Lactobacillus species. Compared with Muc2(-/-)/Retnlb(-/-) mice, this worsened intestinal microbial dysbiosis with a selective loss of colonic Lactobacilli spp. in Muc2(-/-) mice. Orally replenishing Muc2(-/-) mice with murine Lactobacillus spp., but not with a probiotic formulation containing several human Lactobacillus spp. (VSL#3), ameliorated their spontaneous colitis in concert with increased production of short-chain fatty acids. These studies demonstrate that the goblet cell mediator RELM-ß drives colitis in Muc2(-/-) mice by depleting protective commensal microbes. The ability of selective commensal microbial replacement to ameliorate colitis suggests that personalized bacterial therapy may prove beneficial for treatment of UC.

Identification of A3 adenosine receptor agonists as novel non-narcotic analgesics.

Chronic pain negatively impacts the quality of life in a variety of patient populations. The current therapeutic repertoire is inadequate in managing patient pain and warrants the development of new therapeutics. Adenosine and its four cognate receptors (A1 , A2A , A2B and A3 ) have important roles in physiological and pathophysiological states, including chronic pain. Preclinical and clinical studies have revealed that while adenosine and agonists of the A1 and A2A receptors have antinociceptive properties, their therapeutic utility is limited by adverse cardiovascular side effects. In contrast, our understanding of the A3 receptor is only in its infancy, but exciting preclinical observations of A3 receptor antinociception, which have been bolstered by clinical trials of A3 receptor agonists in other disease states, suggest pain relief without cardiovascular side effects and with sufficient tolerability. Our goal herein is to briefly discuss adenosine and its receptors in the context of pathological pain and to consider the current data regarding A3 receptor-mediated antinociception. We will highlight recent findings regarding the impact of the A3 receptor on pain pathways and examine the current state of selective A3 receptor agonists used for these studies. The adenosine-to-A3 receptor pathway represents an important endogenous system that can be targeted to provide safe, effective pain relief from chronic pain.

The Crohn's disease-associated polymorphism in ATG16L1 (rs2241880) reduces SHIP gene expression and activity in human subjects.

Crohn's disease (CD) is a polygenic immune-mediated disease characterized by gastrointestinal inflammation. Mice deficient in the hematopoietic-restricted SH2 domain-containing inositolpolyphosphate 5'-phosphatase (SHIP) develop spontaneous CD-like ileal inflammation. Intriguingly, SHIP mRNA is not upregulated in biopsies from patients with ileal CD despite immune cell infiltration, but SHIP's role in human CD remains unknown. We analyzed SHIP mRNA expression and activity in biopsies and peripheral blood mononuclear cells (PBMCs) from control and treatment-naive subjects with ileal CD, and demonstrated that SHIP mRNA and activity were lower in hematopoietic cells in ileal biopsies and PBMCs from subjects with CD. In all tissues from our patient cohort and in PBMCs from a second healthy control cohort, subjects homozygous for the autophagy-related 16-like protein (ATG16L1) CD-associated gene variant (rs2241880), had low SHIP mRNA expression and activity. SHIP protein expression increased during autophagy and SHIP upregulation was dependent on ATG16L1 and/or autophagy, as well as the ATG16L1 CD-associated gene variant. Finally, homozygosity for the ATG16L1 risk variant and low SHIP mRNA expression is inversely related to increased (LPS+ATP)-induced IL-1ß production by PBMCs in our cohorts and was regulated by increased transcription of ILIB. These data suggest a novel mechanism by which the ATG16L1 CD-associated gene variant may predispose people to develop intestinal inflammation.

Concordance of Mycobacterium tuberculosis fluoroquinolone resistance testing: implications for treatment.

Fluoroquinolone (FQ) drug susceptibility testing (DST) is an important step in the design of effective treatment regimens for multidrug-resistant tuberculosis. Here we compare ciprofloxacin, ofloxacin and moxifloxacin (MFX) resistance results from 226 multidrug-resistant samples. The low level of concordance observed suggests that DST should be performed for the specific FQ planned for clinical use. The results also support the new World Health Organization recommendation for testing MFX at a critical concentration of 2.0 µg/ml.

Maternal exposure to fish oil primes offspring to harbor intestinal pathobionts associated with altered immune cell balance.

Our previous studies revealed that offspring from rat dams fed fish oil (at 8% and 18% energy), developed impaired intestinal barriers sensitizing the colon to exacerbated injury later in life. To discern the mechanism, we hypothesized that in utero exposure to fish oil, rich in n-3 polyunsaturated fatty acid (PUFA), caused abnormal intestinal reparative responses to mucosal injury through differences in intestinal microbiota and the presence of naïve immune cells. To identify such mechanisms, gut microbes and naïve immune cells were compared between rat pups born to dams fed either n-6 PUFA, n-3 PUFA or breeder chow. Maternal exposure to either of the PUFA rich diets altered the development of the intestinal microbiota with an overall reduction in microbial density. Using qPCR, we found that each type of PUFA differentially altered the major gut phyla; fish oil increased Bacteroidetes and safflower oil increased Firmicutes. Both PUFA diets reduced microbes known to dominate the infant gut like Enterobacteriaceae and Bifidobacteria spp. when compared to the chow group. Uniquely, maternal fish oil diets resulted in offspring showing blooms of opportunistic pathogens like Bilophila wadsworthia, Enterococcus faecium and Bacteroides fragilis in their gut microbiota. As well, fish oil groups showed a reduction in colonic CD8+ T cells, CD4+ Foxp3+ T cells and arginase+ M2 macrophages. In conclusion, fish oil supplementation in pharmacological excess, at 18% by energy as shown in this study, provides an example where excess dosing in utero can prime offspring to harbor intestinal pathobionts and alter immune cell homeostasis.

Infections by Renibacterium salmoninarum and Nanophyetus salmincola Chapin are associated with reduced growth of juvenile Chinook salmon, Oncorhynchus tshawytscha (Walbaum), in the Northeast Pacific Ocean.

We examined 1454 juvenile Chinook salmon, Oncorhynchus tshawytscha (Walbaum), captured in nearshore waters off the coasts of Washington and Oregon (USA) from 1999 to 2004 for infection by Renibacterium salmoninarum, Nanophyetus salmincola Chapin and skin metacercariae. The prevalence and intensities for each of these infections were established for both yearling and subyearling Chinook salmon. Two metrics of salmon growth, weight residuals and plasma levels of insulin-like growth factor-1, were determined for salmon infected with these pathogens/parasites, both individually and in combination, with uninfected fish used for comparison. Yearling Chinook salmon infected with R. salmoninarum had significantly reduced weight residuals. Chinook salmon infected with skin metacercariae alone did not have significantly reduced growth metrics. Dual infections were not associated with significantly more severe effects on the growth metrics than single infections; the number of triple infections was very low and precluded statistical comparison. Overall, these data suggest that infections by these organisms can be associated with reduced juvenile Chinook salmon growth. Because growth in the first year at sea has been linked to survival for some stocks of Chinook salmon, the infections may therefore play a role in regulating these populations in the Northeast Pacific Ocean.

Vasoactive intestinal peptide prevents PKCε-induced intestinal epithelial barrier disruption during EPEC infection.

We previously showed that vasoactive intestinal peptide (VIP) protects against bacterial pathogen-induced epithelial barrier disruption and colitis, although the mechanisms remain poorly defined. The aim of the current study was to identify cellular pathways of VIP-mediated protection with use of pharmacological inhibitors during enteropathogenic Escherichia coli (EPEC) infection of Caco-2 cell monolayers and during Citrobacter rodentium-induced colitis. EPEC-induced epithelial barrier disruption involved the PKC pathway but was independent of functional cAMP, Rho, and NF-κB pathways. VIP mediated its protective effects by inhibiting EPEC-induced PKC activity and increasing expression of the junctional protein claudin-4. Short-term treatment with TPA, which is known to activate PKC, was inhibited by VIP pretreatment, while PKC degradation via long-term treatment with TPA mimicked the protective actions of VIP. Immunostaining for specific PKC isotypes showed upregulated expression of PKCθ and PKCε during EPEC infection. Treatment with specific inhibitors revealed a critical role for PKCε in EPEC-induced barrier disruption. Furthermore, activation of PKCε and loss of barrier integrity correlated with claudin-4 degradation. In contrast, inhibition of PKCε by VIP pretreatment or the PKCε inhibitor maintained membrane-bound claudin-4 levels, along with barrier function. Finally, in vivo treatment with the PKCε inhibitor protected mice from C. rodentium-induced colitis. In conclusion, EPEC infection increases intracellular PKCε levels, leading to decreased claudin-4 levels and compromising epithelial barrier integrity. VIP inhibits PKCε activation, thereby attenuating EPEC-induced barrier disruption.

Growth and condition of juvenile coho salmon Oncorhynchus kisutch relate positively to species richness of trophically transmitted parasites.

The aims of this study were first, to test the hypothesis that metrics of fish growth and condition relate positively to parasite species richness (S(R)) in a salmonid host; second, to identify whether S(R) differs as a function of host origin; third, to identify whether acquisition of parasites through marine v. freshwater trophic interactions was related to growth and condition of juvenile salmonids. To evaluate these questions, species diversity of trophically transmitted parasites in juvenile coho salmon Oncorhynchus kisutch collected off the coast of the Oregon and Washington states, U.S.A. in June 2002 and 2004 were analysed. Fish infected with three or more parasite species scored highest in metrics of growth and condition. Fish originating from the Columbia River basin had lower S(R) than those from the Oregon coast, Washington coast and Puget Sound, WA. Parasites obtained through freshwater or marine trophic interactions were equally important in the relationship between S(R) and ocean growth and condition of juvenile O. kisutch salmon.

Repeat treatment of acute hereditary angioedema attacks with open-label icatibant in the FAST-1 trial.

Hereditary angioedema (HAE) is characterized by potentially life-threatening recurrent episodes of oedema. The open-label extension (OLE) phase of the For Angioedema Subcutaneous Treatment (FAST)-1 trial (NCT00097695) evaluated the efficacy and safety of repeated icatibant exposure in adults with multiple HAE attacks. Following completion of the randomized, controlled phase, patients could receive open-label icatibant (30 mg subcutaneously) for subsequent attacks. The primary end-point was time to onset of primary symptom relief, as assessed by visual analogue scale (VAS). Descriptive statistics were reported for cutaneous/abdominal attacks 1-10 treated in the OLE phase and individual laryngeal attacks. Post-hoc analyses were conducted in patients with ≥ 5 attacks across the controlled and OLE phases. Safety was evaluated throughout. During the OLE phase, 72 patients received icatibant for 340 attacks. For cutaneous/abdominal attacks 1-10, the median time to onset of primary symptom relief was 1·0-2·0 h. For laryngeal attacks 1-12, patient-assessed median time to initial symptom improvement was 0·3-1·2 h. Post-hoc analyses showed the time to onset of symptom relief based on composite VAS was consistent across repeated treatments with icatibant. One injection of icatibant was sufficient to treat 88·2% of attacks; rescue medication was required in 5·3% of attacks. No icatibant-related serious adverse events were reported. Icatibant provided consistent efficacy and was well tolerated for repeated treatment of HAE attacks.