Common genetic variants of the human steroid 21-hydroxylase gene (CYP21A2) are related to differences in circulating hormone levels.

PURPOSE: Systematic evaluation of the potential relationship between the common genetic variants of CYP21A2 and hormone levels. METHODS: The relationships of CYP21A2 intron 2 polymorphisms and haplotypes with diverse baseline and stimulated blood hormone levels were studied in 106 subjects with non-functioning adrenal incidentaloma (NFAI). The rationale for using NFAI subjects is dual: i) their baseline hormone profiles do not differ from those of healthy subjects and ii) hormone levels after stimulation tests are available. RESULTS: The carriers (N = 27) of a well-defined CYP21A2 haplotype cluster (c5) had significantly elevated levels of cortisol (p = 0.0110), and 17-hydroxyprogesterone (p = 0.0001) after ACTH stimulation, and 11-deoxycortisol after metyrapone administration (p = 0.0017), but the hormone values were in normal ranges. In addition, the carriers (N = 33) of the C allele of the rs6462 polymorphism had a higher baseline aldosterone level (p = 0.0006). The prevalence of these genetic variants of CYP21A2 did not differ between NFAI and healthy subjects. CONCLUSIONS: The common CYP21A2 variants presumably exert the same effect on hormone levels in the healthy and disease-affected populations. Therefore, they may contribute to complex diseases such as some cardiovascular diseases, and may influence the genotype-phenotype correlation in patients with congenital adrenal hyperplasia (CAH) including the individual need for hormone substitution.

The influence of trigger factors on hereditary angioedema due to C1-inhibitor deficiency.

BACKGROUND: Hereditary angioedema (HAE) resulting from C1-inhibitor deficiency is characterized by attacks of subcutaneous and submucosal edema. Many factors have been presumed to induce edema. Our study analyzed these factors in a fairly large patient population. METHODS: In the first stage of our study, we analyzed the data recorded by 92 subjects in their patient diaries over seven years. The second phase included 27 HAE patients, who had been completing the diary entry 'Trigger factors' every day for seven months whether or not they had experienced an attack. RESULTS: During the initial stage, 91% of the subjects described some factor possibly related to the onset of an attack. They could identify a trigger factor - most commonly (21%) mental stress - in 30% of the 3176 attacks. We found a significant (p < 0.001) difference in the distribution of the trigger factors of the edematous attacks of different locations. The 27 participants of the second phase identified 882 potential trigger factors and recorded 365 attacks. Of these, 246 (67%) occurred on days when the patients identified a potential trigger factor. The likelihood of edema-formation associated with the latter was as follows: menstruation - 63%, infection - 38%, mental stress - 26%, physical exertion - 25%, meteorological changes - 21%, fatigue - 17%. CONCLUSION: This analysis of the trigger factors explored, for the first time, their potential role in inducing HAE attacks. Our findings might open new perspectives in extending the indications for edema-prophylaxis, and could contribute to a better understanding of the pathomechanism of HAE attacks.

Both positive and negative selection pressures contribute to the polymorphism pattern of the duplicated human CYP21A2 gene.

The human steroid 21-hydroxylase gene (CYP21A2) participates in cortisol and aldosterone biosynthesis, and resides together with its paralogous (duplicated) pseudogene in a multiallelic copy number variation (CNV), called RCCX CNV. Concerted evolution caused by non-allelic gene conversion has been described in great ape CYP21 genes, and the same conversion activity is responsible for a serious genetic disorder of CYP21A2, congenital adrenal hyperplasia (CAH). In the current study, 33 CYP21A2 haplotype variants encoding 6 protein variants were determined from a European population. CYP21A2 was shown to be one of the most diverse human genes (HHe=0.949), but the diversity of intron 2 was greater still. Contrary to previous findings, the evolution of intron 2 did not follow concerted evolution, although the remaining part of the gene did. Fixed sites (different fixed alleles of sites in human CYP21 paralogues) significantly accumulated in intron 2, indicating that the excess of fixed sites was connected to the lack of effective non-allelic conversion and concerted evolution. Furthermore, positive selection was presumably focused on intron 2, and possibly associated with the previous genetic features. However, the positive selection detected by several neutrality tests was discerned along the whole gene. In addition, the clear signature of negative selection was observed in the coding sequence. The maintenance of the CYP21 enzyme function is critical, and could lead to negative selection, whereas the presumed gene regulation altering steroid hormone levels via intron 2 might help fast adaptation, which broadly characterizes the genes of human CNVs responding to the environment.

Association of ficolin-3 with severity and outcome of chronic heart failure.

BACKGROUND: Inflammatory mechanisms involving complement activation has been shown to take part in the pathophysiology of congestive heart failure, but the initiating mechanisms are unknown. We hypothesized that the main initiator molecules of the lectin complement pathway mannose-binding lectin (MBL), ficolin-2 and ficolin-3 were related to disease severity and outcome in chronic heart failure. METHODS AND RESULTS: MBL, ficolin-2 and ficolin-3 plasma concentrations were determined in two consecutive cohorts comprising 190 patients from Hungary and 183 patients from Norway as well as controls. Disease severity and clinical parameters were determined at baseline, and all-cause mortality was registered after 5-years follow-up. In univariate analysis a low level of ficolin-3, but not that of MBL or ficolin-2, was significantly associated with advanced heart failure (New York Heart Association Class IV, p<0.001 for both cohorts) and showed inverse correlation with B- type natriuretic peptide (BNP) levels (r = -0.609, p<0.001 and r = -0.467, p<0.001, respectively). In multivariable Cox regression analysis, adjusted for age, gender and BNP, decreased plasma ficolin-3 was a significant predictor of mortality (HR 1.368, 95% CI 1.052-6.210; and HR 1.426, 95% CI 1.013-2.008, respectively). Low ficolin-3 levels were associated with increased complement activation product C3a and correspondingly decreased concentrations of complement factor C3. CONCLUSIONS: This study provides evidence for an association of low ficolin-3 levels with advanced heart failure. Concordant results from two cohorts show that low levels of ficolin-3 are associated with advanced heart failure and outcome. The decrease of ficolin-3 was associated with increased complement activation.

Effective humoral immunity against diphtheria and tetanus in patients with systemic lupus erythematosus or myasthenia gravis.

INTRODUCTION: Controversy exists about the effectiveness of vaccine-induced immune response in patients with immunoregulatory disorders. Our aim was to determine the antibody titers to diphtheria and tetanus in patients with either of two autoimmune diseases. METHODS: 279 patients with SLE (205 females, aged 45.0 ± 13.8 years), 158 patients with myasthenia gravis (MG) (101 females, aged 55 ± 18.7 years) and 208 healthy subjects (122 females, aged 48 ± 14.6 years) were enrolled. Serum concentrations of diphtheria-antitoxin-IgG (A-DIPHTH) and tetanus-antitoxoid-IgG (A-TET) were determined with ELISA. RESULTS: Equal proportions of healthy subjects, as well as patients with SLE or MG exhibited proper antibody responses and immune protection against diphtheria and tetanus. In all three test groups, serum concentration of A-DIPHTH decreased significantly (p<0.001) with age throughout the study population, while titers of A-TET dropped only in the elderly (>60-years-old) subjects. There were no significant differences among the groups in the age-related changes of A-TET and A-DIPHTH except that in <40-years-old subjects, A-DIPHTH level was significantly (p=0.029) lower in SLE patients than in controls. CONCLUSIONS: Our findings suggest that the level of vaccine-induced immunity against diphtheria and tetanus infections in patients with SLE or MG is comparable to the healthy population.

Elevated levels of mitochondrial mortalin and cytosolic HSP70 in blood as risk factors in patients with colorectal cancer.

Mortalin/GRP75 is a ubiquitous mitochondrial chaperone related to the cytosolic heat shock protein 70 (HSP70). It protects cells from senescence and apoptosis and is overexpressed in cancer cells. Cell resistance to complement-dependent cytotoxicity depends on mortalin and during complement attack mortalin is released from cells. Our goal was to determine whether cancer patients have circulating mortalin in blood. The significance of mortalin in blood to survival prospects of colorectal cancer patients was evaluated. Occurrence of extracellular soluble HSP70 (sHSP70) is documented. We developed a sensitive ELISA for mortalin. The association between mortalin level and survival was subjected to the Cox proportional hazards analysis (univariate and multivariate analyses). Mortalin concentration in serum of colorectal cancer patients was 10-214 ng/ml. Survival data of the patients were known from an earlier study of sHSP70 in these samples. Cox regression analysis indicated that high mortalin (>60 ng/ml) is a risk factor for shorter survival. Serum levels of sHSP70 and mortalin in patients were independent variables. Concurrence of high sHSP70 and mortalin was associated with rapid disease progression (HR = 4, 2.04-8.45, p < 0.001). Addition of high sHSP70 and mortalin to a baseline model of age, sex and TNM stage, significantly (p < 0.001) enhanced the risk score to 8 (3.26-20.46). This is the first demonstration of circulating mortalin in cancer patients. Analysis of mortalin in blood, and even more so of mortalin and sHSP70, adds a high prognostic value to the TNM stage and will identify colorectal cancer patients at high risk of poor survival.

The role of ficolins and MASPs in hereditary angioedema due to C1-inhibitor deficiency.

BACKGROUND AND OBJECTIVE: Hereditary angioedema due to C1-inhibitor deficiency (HAE-C1-INH) causes disturbances in the complement system. However, the influence of HAE-C1-INH on the lectin pathway of complement is unresolved. Thus, we studied the main initiator molecules, enzymes and regulators in the lectin pathway in patients with HAE-C1-INH. METHODS: The serum concentrations of ficolin-2, ficolin-3, MBL, MASP-2, MASP-3, and MAP-1 were measured during symptom-free periods in 91 patients with HAE-C1-INH, and in 100 healthy controls using sandwich ELISAs. RESULTS: Compared with controls, the levels of ficolin-2 (p<0.0001) and MASP-2 (p=0.0238) were reduced, while the levels of MBL and MASP-3 were elevated (p=0.0028 and p<0.0001, respectively) in HAE-C1-INH patients. Ficolin-3 and MAP-1 levels did not differ significantly between the two groups. Ficolin-2 correlated with MASP-3 in patients (r=0.3443, p=0.0008), while these parameters showed an opposite relationship in controls (r=-0.4625, p<0.0001). In the patients, ficolin-3 correlated with MASP-2 (r=0.3698, p=0.001). Ficolin-2, -3, and MAP-1 correlated negatively with the annual requirement of plasma derived C1-INH concentrate (r=-0.2863, p=0.0059; r=-0.2654, p=0.0110 and r=-0.2501, p=0.0168, respectively). Ficolin-3 showed a negative correlation with the annual number of attacks (r=-0.2478, p=0.0179). CONCLUSIONS: We found significant differences between patients and controls in the levels of some of the molecules belonging to the lectin complement pathway. Low concentrations of particularly ficolin-2 and -3 were inversely correlated with the severity of HAE-C1-INH, while this was not observed for MBL. This suggests a previously unrecognized involvement of the ficolin-dependent lectin complement pathway in the pathophysiology of HAE-C1-INH.

A novel assay to quantitate MASP-2/ficolin-3 complexes in serum.

Ficolin-1, -2 and -3 are recognition molecules in the lectin complement pathway and form complexes with serine proteases named MASP-1, -2 and -3 and two nonenzymatic proteins. MASP-2 is the main initiator of lectin pathway activation, while ficolin-3 is the most abundant ficolin molecule in the circulation. The significance of lectin pathway complexes in the circulation is unknown. Thus, we established an assay for the measurement of circulating MASP-2/ficolin-3 complexes. A quantitative sandwich ELISA was developed for the measurement of the MASP-2/ficolin-3 complexes in serum based on monoclonal antibodies against MASP-2 for coating and anti-ficolin-3 for detection. In addition, we assessed the serum concentrations of ficolin-3 and MASP-2 and the extent of ficolin-3 mediated C4 deposition on acetylated BSA in samples from 97 healthy donors. The median concentration of MASP-2/ficolin-3 complexes was found to be 119.7 AU/ml (range: 2.9-615.5 AU/ml). Significant correlations were found between the level of MASP-2/ficolin-3 complexes and the concentration of ficolin-3 (Spearman r=0.2532, p=0.0124), and MASP-2 (Spearman r=0.4505, p<0.0001), as well as the degree of C4 deposition (Spearman r=0.671, p<0.0001). When ficolin-3 deficient (homozygous for the rs28357092 polymorphism) and MASP-2 deficient (homozygous for the rs72550870 polymorphism) sera were incubated together, complex formation was induced between MASP-2 and ficolin-3. The complex formation disappeared in the presence of EDTA. An assay allowing quantitative measurement exclusively of MASP-2/ficolin-3 complexes in serum is described. This method may add further insight into the pathophysiology of disorders associated with the deficiency or abnormal activities of MASP-2 and ficolin-3.

Elevated C1rC1sC1inh levels independently predict atherosclerotic coronary heart disease.

UNLABELLED: Clinical studies as well as animal models emphasized the importance of the complement system in the pathogenesis of coronary atherosclerosis and cardiovascular diseases. Our aim was to examine the extent and clinical implication of complement system activation in patients with stable atherosclerotic coronary heart disease (ACHD). Seventy-six patients with stable angina pectoris (SAP) scheduled for elective coronary angiography were enrolled into the study. Percutaneous coronary intervention (PCI) was performed in 24 patients, in 27 patients (NOPCI group) the coronary angiography showed significant stenosis and bypass surgery (CABG) or optimal medical therapy (OMT) were advised, whereas in 25 patients the coronary angiography was negative (NC group). 115 volunteers served as healthy controls (HC). In all individuals, the plasma level of several complement activation products - C1rC1sC1inh, C3bBbP and SC5b-9 - were determined on admission, strictly before the coronary angiography. In patients with angiographically proven ACHD (PCI and NOPCI groups), the baseline C1rC1sC1inh levels were significantly higher compared to NC group and HC (p<0.0001, for both comparisons). According to the multiple logistic regression analysis, high C1rC1sC1inh level proved to be an independent biomarker of coronary heart disease (p<0.026, OR: 65.3, CI: 1.628-2616.284). CONCLUSION: Activation of the classical complement pathway can be observed in angiographically proven coronary atherosclerosis. Elevated C1rC1sC1inh levels might represent an useful biomarker for coronary artery disease.

Intraspecific evolution of human RCCX copy number variation traced by haplotypes of the CYP21A2 gene.

The RCCX region is a complex, multiallelic, tandem copy number variation (CNV). Two complete genes, complement component 4 (C4) and steroid 21-hydroxylase (CYP21A2, formerly CYP21B), reside in its variable region. RCCX is prone to nonallelic homologous recombination (NAHR) such as unequal crossover, generating duplications and deletions of RCCX modules, and gene conversion. A series of allele-specific long-range polymerase chain reaction coupled to the whole-gene sequencing of CYP21A2 was developed for molecular haplotyping. By means of the developed techniques, 35 different kinds of CYP21A2 haplotype variant were experimentally determined from 112 unrelated European subjects. The number of the resolved CYP21A2 haplotype variants was increased to 61 by bioinformatic haplotype reconstruction. The CYP21A2 haplotype variants could be assigned to the haplotypic RCCX CNV structures (the copy number of RCCX modules) in most cases. The genealogy network constructed from the CYP21A2 haplotype variants delineated the origin of RCCX structures. The different RCCX structures were located in tight groups. The minority of groups with identical RCCX structure occurred once in the network, implying monophyletic origin, but the majority of groups occurred several times and in different locations, indicating polyphyletic origin. The monophyletic groups were often created by single unequal crossover, whereas recurrent unequal crossover events generated some of the polyphyletic groups. As a result of recurrent NAHR events, more CYP21A2 haplotype variants with different allele patterns belonged to the same RCCX structure. The intraspecific evolution of RCCX CNV described here has provided a reasonable expectation for that of complex, multiallelic, tandem CNVs in humans.

Complement anaphylatoxin C3a as a novel independent prognostic marker in heart failure.

OBJECTIVES: The purpose of this study was to evaluate complement activation in a heart failure cohort. Based on their powerful biological activity, we hypothesized that the levels of anaphylatoxin C3a are related to pathological signs and outcomes in heart failure. DESIGN, SETTING AND PATIENTS: Complement activation products C3a and SC5b9 were determined in 182 consecutive CHF patients (single centre, prospective cohort study), with a left ventricular ejection fraction <45%. Mortality and re-hospitalisation due to the progression of CHF were assessed after a median follow-up of 14 months. INTERVENTIONS: None. RESULTS: In the univariate analysis, high level of anaphylatoxin C3a was significantly associated with clinical events (p < 0.0001), whereas SC5b9 showed a tendency of association (p = 0.094). In multivariable Cox analysis, adjusted for age, NT-proBNP, diastolic blood pressure, body mass index (BMI), haemoglobin and creatinine levels, C3a was a significant predictor of HF-related re-hospitalization or death (HR 1.189 per 1-SD increase, 95% CI 1.023-1.383), and of cardiovascular events or death (HR 1.302, CI 1.083-1.566). C3a was strongly associated with the presence of peripheral oedema, inflammatory markers (CRP, prealbumin, IL-6, sTNFRI, sTNFRII), heat-shock protein 70 levels and endothelial activation markers (von-Willebrand factor and endothelin-1). CONCLUSIONS: Results of the present study showed that complement activation is strongly linked to unfavourable outcomes in heart failure. High levels of anaphylatoxin C3a predicted re-hospitalization, cardiovascular events and mortality in adjusted survival model. Increased C3a levels were associated with biomarkers of acute-phase reaction, inflammation, cellular stress response, endothelial-cell activation and oedematous complications independently from disease severity.

ACTH-induced cortisol release is related to the copy number of the C4B gene encoding the fourth component of complement in patients with non-functional adrenal incidentaloma.

OBJECTIVE: According to our previous findings, carriers of the C4B*Q0 genotype, which means zero or one copy of the C4B gene, which is located in the RCCX copy number variation region on chromosome 6, have a significantly shorter life-expectancy and higher risk of cardiovascular disease than non-carriers. We have postulated that the C4B*Q0 genotype is linked to variant(s) of the neighboring CYP21A2 gene encoding a steroid 21-hydroxylase with altered function. DESIGN: Single-center, observational, retrospective study. PATIENTS: Seventy-six patients with non-functional, benign adrenal incidentaloma. MEASUREMENTS: Serum cortisol, aldosterone, 17-hydroxyprogesterone, corticosterone and ACTH levels basally and after ACTH-stimulation, metyrapone or dexamethasone tests were determined. C4B gene copy number was quantified. RESULTS: The ratio of ACTH-stimulated and baseline cortisol concentrations was significantly higher (P = 0·001) in the group of patients carrying the C4B*Q0 genotype compared to the rest of the patients. This difference remained significant (P = 0·004) after adjustment for sex and age, as well as for tumor size. A significant (P = 0·018), adjusted difference between carriers and non-carriers was found also for ACTH-induced/basal aldosterone ratio. In C4B*Q0 carriers, metyrapone hardly reduced the serum cortisol level, while in non-carriers it induced a highly significant (P = 0·002) decrease. CONCLUSIONS: The C4B*Q0 genotype may be associated with hyperreactivity of the HPA axis (manifested as an increased responsiveness to ACTH-stimulation), probably through enhanced function of steroid 21-hydroxylase. Since hyperreactivity of the HPA axis is known to be associated with an increased risk of cardiovascular disease, our present findings may explain the increased cardiovascular morbidity and mortality of C4B*Q0 carriers.

Comparison of epitope specificity of anti-heat shock protein 60/65 IgG type antibodies in the sera of healthy subjects, patients with coronary heart disease and inflammatory bowel disease.

Previously, we reported on the presence of antibodies to linear epitopes of human and mycobacterial 60 kD heat shock proteins (HSP) in the sera of healthy blood donors. Since many recent findings indicate that the levels of these antibodies may be altered in coronary heart disease (CHD) and also inflammatory bowel diseases (IBD), it seemed worthwhile to compare the epitope specificity of the anti-HSP60 and anti-HSP65 antibodies in the sera of patients with these diseases to those in healthy subjects. The multipin enzyme-linked immunosorbent assay method was applied with a large overlapping set of synthetic 10-mer peptides covering selected regions of human HSP60 and Mycobacterium bovis HSP65. Sera of 12 healthy persons (HP), 14 CHD, and 14 IBD patients with the same concentration of total anti-HSP60 and HSP65 IgG antibodies were tested. We have identified CHD-specific epitopes in the equatorial domain of the HSP60 protein but in neither region of the HSP65 molecule, indicating that the formation of anti-HSP60 antibodies is not or only partially due to the cross-reaction between human HSP60 and bacterial HSP65. IBD-specific epitopes were found in many regions of the HSP60 and in even more regions of the HSP65 molecule including an IBD-specific T cell epitope in region X as well. These findings indicate that the epitope specificity of the anti-human and anti-mycobacterial HSP60 antibodies associated with various diseases is different.

Strong correlation of high EBNA-1-IgG levels with edematous attacks involving upper airway mucosa in hereditary angioedema due to C1-inhibitor deficiency.

Elevated level of IgG-type antibodies against Type 1 nuclear antigen (anti-EBNA-1-IgG) of the Epstein-Barr virus is a strong risk factor for certain autoimmune diseases. We measured anti-EBNA-1 IgG titers in 107 patients with hereditary angioedema due to C1-inhibitor deficiency (HAE-C1-INH). In the sera from 33 longitudinally tested patients, we found a very strong correlation (R>0.75, p=0.0005) between anti-EBNA-1-IgG titers measured in 2004 and 2010, respectively. High (>200 U/ml) anti-EBNA-1 levels were strongly correlated with the frequency of upper airway attacks (p=0.003) and the dose requirement of C1-inhibitor concentrate (p=0.008), while no significant association with the frequency of subcutaneous and abdominal attacks was found. These novel findings indicate that the underlying/triggering mechanisms of upper airway attacks in HAE-C1-INH may differ from that of other types of attacks and measurement of the anti-EBNA-1 IgG levels may be suitable for the prediction of upper airway attacks and C1-inhibitor concentrate requirement in HAE-C1-INH patients.

Low ficolin-3 levels in early follow-up serum samples are associated with the severity and unfavorable outcome of acute ischemic stroke.

BACKGROUND: A number of data indicate that the lectin pathway of complement activation contributes to the pathophysiology of ischemic stroke. The lectin pathway may be triggered by the binding of mannose-binding lectin (MBL), ficolin-2 or ficolin-3 to different ligands. Although several papers demonstrated the significance of MBL in ischemic stroke, the role of ficolins has not been examined. METHODS: Sera were obtained within 12 hours after the onset of ischemic stroke (admission samples) and 3-4 days later (follow-up samples) from 65 patients. The control group comprised 100 healthy individuals and 135 patients with significant carotid stenosis (patient controls). The concentrations of ficolin-2 and ficolin-3, initiator molecules of the lectin complement pathway, were measured by ELISA methods. Concentration of C-reactive protein (CRP) was also determined by a particle-enhanced immunturbidimetric assay. RESULTS: Concentrations of both ficolin-2 and ficolin-3 were significantly (p < 0.001) decreased in both the admission and in the follow-up samples of patients with definite ischemic stroke as compared to healthy subjects. Concentrations of ficolin-2 and ficolin-3 were even higher in patient controls than in healthy subjects, indicating that the decreased levels in sera during the acute phase of stroke are related to the acute ischemic event. Ficolin-3 levels in the follow-up samples inversely correlated with the severity of stroke indicated by NIH scale on admission. In follow-up samples an inverse correlation was observed between ficolin-3 levels and concentration of S100ß, an indicator of the size of cerebral infarct. Patients with low ficolin-3 levels and high CRP levels in the follow up samples had a significantly worse outcome (adjusted ORs 5.6 and 3.9, respectively) as measured by the modified Rankin scale compared to patients with higher ficolin-3 and lower CRP concentrations. High CRP concentrations were similarly predictive for worse outcome, and the effects of low ficolin-3 and high CRP were independent. CONCLUSIONS: Our findings indicate that ficolin-mediated lectin pathways of complement activation contribute to the pathogenesis of ischemic stroke and may be additive to complement-independent inflammatory processes.

Lack of increased prevalence of immunoregulatory disorders in hereditary angioedema due to C1-inhibitor deficiency.

Hereditary angioedema due to deficiency of C1-INH (HAE-C1-INH) is associated with enhanced consumption of the early complement components, which may predispose for autoimmune disease. We assessed the prevalence of such disorders among HAE- C1-INH patients and their impact on the natural course of HAE-C1-INH. Clinical data and immunoserological parameters of 130 HAE-C1-INH and 174 non-C1-INH-deficient patients with angioedema were analyzed. In our study, the incidence of immunoregulatory disorders was 11.5% in the population of HAE-C1-INH patients and 5.2% among non-C1-INH-deficient controls with angioedema. Immunoserology screening revealed a greater prevalence of anticardiolipin IgM (p=0.0118) among HAE-C1-INH patients, than in those with non-C1-INH-deficient angioedema. We did not find higher prevalence of immunoregulatory disorders among our HAE-C1-INH patients. However, in patients with confirmed immunoregulatory disorders, the latter influenced both the severity of HAE-C1-INH and the effectiveness of its long-term management. Appropriate management of the immunoregulatory disease thus identified improves the symptoms of HAE-C1-INH.