An association between C1 esterase inhibitor deficiency and lupus erythematosus: report of two cases and review of the literature

Hereditary angioedema and lupus: A French retrospective study and literature review

Hereditary angioedema (HAE) is a rare genetic disorder that is primarily caused by a defect in the C1 inhibitor (C1-INH). The recurrent symptoms are subcutaneous edema and abdominal pain. Laryngeal edema, which can also occur, is life threatening if it goes untreated. HAE can be associated with some inflammatory and autoimmune disorders, particularly lupus. The aim of this study was to describe cases of lupus among HAE patients in France and to perform a literature review of lupus and HAE studies. Case detection and data collection (a standardized form) were performed, thanks to the French Reference Center for Kinin-related angioedema. Data were collected from 6 patients with type 1 HAE and lupus in France; no cases of systemic lupus erythematosus were reported. In the literature review, 32 cases of lupus combined with HAE were identified, including 26 female patients. The median patient age at the time of first reported HAE symptoms and at diagnosis were 17.5 years (range, 9-41 years) and 19 years (range, 9-64 years), respectively for our 6 patients and 14 years (range, 3-30 years) and 17 years (range, 7-48 years), respectively, for the literature review. The clinical manifestations of HAE were mainly abdominal pain (83% in our patients vs 47% in the literature) and edema of the limbs (83% vs 38%). The C4 levels were low (for 100% of our cases vs 93% in the literature). Eighteen patients in the literature demonstrated HAE symptoms prior to the lupus onset vs 5 for our patients. The mean patient age at lupus onset was 20 years (range, 13-76 years) for our patients and 19.5 years (range, 1-78 years) in the literature, respectively. In the literature, 81% of the patients had skin manifestations, 25% had renal involvement and 28% received systemic steroids to treat lupus. Treatment with danazol did not modify the clinical expression of lupus. The association between lupus and HAE is a rare but not unanticipated event. Patients are often symptomatic for HAE before developing lupus. Lupus cases associated with HAE share some characteristics of lupus cases related to other complement deficiencies, such as the absence of severity and the predominance of cutaneous symptoms.

Prevalence of autoantibodies in a group of hereditary angioedema patients

Hereditary Angioedema is a dominantly inherited disease. Routine screening of autoantibodies (AAB) is not recommended for individuals with Hereditary Angioedema; however, prevalence of these antibodies in Hereditary Angioedema patients is not well documented. We aim to determine the prevalence of AAB so that individuals at risk of developing autoimmune diseases can be identified. Fifteen patients with Hereditary Angioedema attended at Clementino Fraga Filho University Hospital accepted to participate in this study. Prevalence of AAB was 40%. Our data indicate high prevalence of AAB in patients with Hereditary Angioedema. Large-scale studies should be considered to determine the significance of these AAB in the follow-up care of patients with Hereditary Angioedema.

The autoreactivity of B cells in hereditary angioedema due to C1 inhibitor deficiency

Patients with hereditary angioedema (HAE) tend to produce autoantibodies and have a propensity to develop immunoregulatory disorders. We characterize the profile of autoantibodies in a group of HAE patients and investigate their memory B cells' phenotype and activation status. We studied the activity status phenotype, Toll-like receptor (TLR)-9 expression and total phosphotyrosine in B cells isolated from HAE patients. Additionally, the following autoantibodies were assessed in the serum of 61 HAE patients: anti-nuclear, rheumatoid factor, anti-cardiolipin, anti-tissue transglutaminase, anti-endomysial, anti-Saccharomyces cerevisiae, anti-thyroid and anti-neutrophil cytoplasmic antibodies. In 47·5% of HAE patients we detected at least one of the tested autoantibodies. Expression of CD69, CD5 and CD21 was found to be significantly higher on memory B cells from HAE patients compared to healthy controls (4·59 ± 4·41 versus 2·06 ± 1·81, P = 0·04, 8·22 ± 7·17 versus 3·65 ± 3·78, P = 0·05, 2·43 ± 0·54 versus 1·92 ± 0·41, P = 0·01, respectively). Total phosphotyrosine in B cells from HAE patients was significantly higher compared to healthy controls (4·8 ± 1·1 versus 2·7 ± 1·3, P = 0·0003). Memory B cells isolated from the HAE group contained higher amounts of TLR-9 compared to healthy controls (8·17 ± 4·1 versus 4·56 ± 1·6, P = 0·0027). Furthermore, the expression of TLR-9 in memory B cells from HAE patients with autoantibodies was significantly higher than the control group (10 ± 4·7 versus 4·56 ± 1·6, P = 0·0002) and from that in HAE patients without autoantibodies (10 ± 4·7 versus 5·8 ± 0·9, P = 0·036). HAE patients have enhanced production of autoantibodies due most probably to the increased activation of B cells, which was found to be in association with a high expression of TLR-9.

Lupus erythematosus associated with C1 inhibitor deficiency

We report here a patient with skin lesions of lupus erythematosus (LE) associated with a type 1 hereditary C1 inhibitor deficiency. She had not experienced any episodes of angioedema. A histological examination of the affected skin lesions demonstrated liquefaction of the basal cell layer in the perifollicule. Direct immunofluorescence staining revealed the granular deposition of IgM along the dermo-epidermal junction. Blood laboratory examinations revealed low levels of CH50, C1q, C4, C2 and C1 inhibitor, but the C3 and C5 levels were within normal limits. Similar reductions in the C1 inhibitor levels were observed in 2 out of 3 sisters. Although one sister has been asymptomatic until now, the other has suffered from SLE. The antinuclear antibody titer was negative initially, but has changed to positive. The skin lesions became pigmented following topical corticosteroid therapy, but the deficient complement component levels remained unchanged. We also reviewed 23 cases in the literature of hereditary C1 inhibitor deficiency associated with SLE, DLE, LE-like eruption, and SCLE and discussed several common characteristics such as a female predominance, a high incidence of antinuclear antibodies, cutaneous manifestations, and photosensitivity.

[Non-allergic angioedema: update]

PURPOSE

Nonallergic isolated angioedema is an uncommon clinical syndrome raising difficult diagnosis and therapeutic problems. Occurrences linked to a C1Inh are the predominant ones and have to be examined as a priority, taking into account the specificity of the associated follow-up.

CURRENT KNOWLEDGE AND KEY POINTS

Diseases with a clinical profile close to hereditary angioneurotic edema, but without C1Inh anomaly, have been described recently. It is in fact family cases, concerning only women, where estrogens seem to play a dominant role. Angioedema's secondary aspects are gathering various pathologies (vasculitis, Gleich's syndrome, angioedema initiated by physical agents). The role played by some drugs must not be forgotten, mainly angiotensin converting enzyme inhibitors, which are at the origin of angiodema in nearly 0.5% of users.

FUTURE PROSPECT AND PROJECTS

Uncontrolled activation of the contact system seems to play a major role in the main part of these angiodemas. The efficiency of the tranexaminic acid (which modulates its activation) is to be taken as evident. The key to the future seems to be the development of plasmin and bradykinin inhibitors.

Acquired C1 esterase inhibitor deficiency

Acquired C1 esterase inhibitor deficiency is a rare condition associated with autoimmune or low-grade lymphoproliferative disorders. Adults or elderly patients are most commonly affected. The diagnosis is suspected when patients present with recurrent angioedema and low serum levels of C4 with normal levels of C3. Low levels of C1q and low C1 esterase inhibitor activity confirm the diagnosis. In this paper, we summarize experience with 22 cases of acquired C1 esterase inhibitor deficiency in the context of a review of the published literature on diagnosis and treatment of this condition.

Acquired deficiency in C1-inhibitor associated with signet ring cell gastric adenocarcinoma: a probable connection of antitumor-associated antibodies, hemolytic anemia, and complement turnover

BACKGROUND

Acquired deficiency in C1-inhibitor (C1-INH) associated with malignancy is often asymptomatic because clinical manifestations are not dependent on a critical complement threshold (in contrast to hereditary C1-INH deficiency). Increased complement consumption involving different kinds of antibodies is the postulated mechanism for this disease, but other factors must play an important role.

CASE REPORT

A 76-year-old woman with unremarkable medical history experienced three episodes of angioedema over 6 months. Investigations revealed a complement profile characteristic of acquired deficiency in C1-INH, a hemolytic anemia, and a signet ring cell adenocarcinoma (linitis plastica). A gastrectomy and a splenectomy were performed. The postoperative course was characterized by a complete disappearance of the symptoms of angioedema and hemolytic anemia. A local recurrence of the tumor 5 months later could not be resected. The patient died 17 months after the initial surgery was performed.

RESULTS

Quantitative and functional analyses of the complement factors showed persistent excessive complement consumption. Markers of hemolytic anemia disappeared after tumor removal but recurred in the second part of the disease evolution. Immunohistochemical findings in tumor tissue showed loss of normal blood group antigens but expression of Lea antigen, as well as C1q deposition.

CONCLUSION

To explain the whole clinical and laboratory picture, we hypothesize a connection between tumor immunohistochemical profile, complement consumption, and hemolytic anemia. Tumor cell surface antigens might lead to a permanent but asymptomatic complement consumption that is worsened and becomes clinically manifest by superimposed hemolytic anemia caused by cross-reactive antibodies to newly expressed blood group antigens on tumor cells. This hypothesis should be confirmed by other observations.

Protein S deficiency in lupus erythematosus secondary to hereditary angio-oedema

We report a child with lupus erythematosus secondary to type 2 hereditary angio-oedema (HAE). Reduced levels of free protein S were found. Total protein S, and C4 binding protein (C4bp) were normal, and there was no evidence of anticardiolipin antibodies or lupus anticoagulant. We postulate that reduced levels of C4, secondary to C1 inhibitor deficiency, resulted in increased binding of protein S to C4bp, leading to reduced levels of free protein S and thus functional deficiency of protein S.

Hereditary angioedema and aortitis

A 28-year-old male with hereditary angioedema died of an extensive stroke. Autopsy revealed cicatricial aortitis with narrowing of the coronary ostia, myocardial infarctions, and a left ventricular mural thrombus. There was neither acute inflammation of the aorta nor systemic vasculitis. A possible association of the aortitis with the hereditary angioedema is discussed.

A family with hereditary angioedema and multiple immunologic disorders

A 58-year-old man with end-stage renal disease treated with long-term ambulatory peritoneal dialysis gave a history of hereditary angioedema. Results of testing of his serum for antinuclear antibody were strongly positive, and a titer of 1:2,560 for antiribosomal antibody was documented. Three of his six children reported multiple medical problems, including episodic swelling, discoid lupus, and arthritis. An indepth study of this kindred showed a number of associated immunologic disturbances. Three children had decreased C1 esterase inhibitor and decreased C4 levels. T cell enumeration revealed low proportions of suppressor cells in these three children as well as in another unaffected child. Serum IgM level was low in the propositus, and IgG level was also decreased in one of the affected children. HLA typing failed to show a clear association of class I or class II antigens with hereditary angioedema. Family members tested did not demonstrate anti-SS-A, anti-SS-B, antinuclear antibody, anti-double-stranded DNA, anti-Sm, or anti-ribonuclear protein antibodies.

Hereditary angioedema and thyroid autoimmunity

Sera from 91 patients with hereditary angioedema were screened for thyroid antibodies. The results for the 77 patients more than 17 years old were compared with previously published data for the prevalence of thyroid disease in a large community (Whickham). Of the female patients with hereditary angioedema, the prevalence of thyroglobulin antibodies (TGA) was 14.0%, higher than the expected 3% (p less than 0.001). The prevalence of thyroid microsomal antibodies (TMA) was 20%, also higher than the expected 7.6% (p less than 0.01). The age distributions of the females in both groups differed: in the group with hereditary angioedema there was a greater proportion of younger patients which should have resulted in a lower prevalence of thyroid antibodies. Adjusting for related patients with hereditary angioedema, there was still an increased prevalence of TGA (p less than 0.01) and TMA (p less than 0.01).

Inherited disorders of complement

Isolated complement component deficiencies are uncommon. Deficiencies of all eleven components and two inhibitors of the classical pathway have been described. Complete absence of the components of the alternative pathway has not been described. The consequences of a single defect in complement are often predictable from an understanding of the biologic activities associated with activation of the complement system. Deficiency of C1 esterase inhibitor gives rise to the disease, hereditary angioedema; deficiency of the early components of the classical pathway are associated with lupus erythematosus; C3 and C3 inactivator deficiencies with pyogenic infections; C5 dysfunction with Leiner's disease; deficiencies of the terminal components with recurrent Neisseria bacteremia; and C9 deficiency with normal health. The complement system and its associated biologic activities are reviewed. The present knowledge of the inherited complement deficiencies and associated diseases, with particular emphasis on the dermatologic manifestations, genetics, and diagnosis, is summarized.