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

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.

Angioedema

Angioedema can be caused by either mast cell degranulation or activation of the kallikrein-kinin cascade. In the former case, angioedema can be caused by allergic reactions caused by immunoglobulin E (IgE)-mediated hypersensitivity to foods or drugs that can also result in acute urticaria or a more generalized anaphylactic reaction. Nonsteroidal anti-inflammatory drugs (cyclooxygenase 1 inhibitors, in particular) may cause angioedema with or without urticaria, and leukotrienes may have a particular role as a mediator of the swelling. Reactions to contrast agents resemble allergy with basophil and mast cell degranulation in the absence of specific IgE antibody and can be generalized, that is, anaphylactoid. Angioedema accompanies chronic urticaria in 40% of patients, and approximately half have an autoimmune mechanism in which there is IgG antibody directed to the subunit of the IgE receptor (40%) or to IgE itself (5%-10%). Bradykinin is the mediator of angioedema in hereditary angioedema types I and II (C1 inhibitor [INH] deficiency) and the newly described type III disorder some of which are caused bya mutation involving factor XII. Acquired C1 INH deficiency presents in a similar fashion to the hereditary disorder and is due either toC1 INH depletion by circulating immune complexes or to an IgG antibody directed to C1 INH. Although each of these causes excessive bradykinin formation because of activation of the plasma bradykinin-forming pathway, the angioedema due to angiotensin-converting enzyme inhibitors is caused by excessive bradykinin levels due to inhibition of bradykinin degradation. Idiopathic angioedema (ie, pathogenesis unknown) may be histaminergic, that is, caused by mast cell degranulation with histamine release, or nonhistaminergic. The mediator pathways in the latter case are yet to be defined. A minority may be associated with the same autoantibodies associated with chronic urticaria. Angioedema that is likely to be life threatening (laryngeal edema or tongue/pharyngeal edema that obstructs the airway) is seen in anaphylactic/anaphylactoid reactions and the disorders mediated by bradykinin.

Angioedema

Although first described more than 130 years ago, the pathophysiology, origin, and management of the several types of angioedema are poorly understood by most dermatologists. Although clinically similar, angioedema can be caused by either mast cell degranulation or activation of kinin formation. In the former category, allergic and nonsteroidal anti-inflammatory drug-induced angioedema are frequently accompanied by urticaria. Idiopathic chronic angioedema is also usually accompanied by urticaria, but can occur without hives. In either case, an autoimmune process leading to dermal mast cell degranulation occurs in some patients. In these patients, histamine-releasing IgG anti-FcepsilonR1 autoantibodies are believed to be the cause of the disease, removal or suppression by immunomodulation being followed by remission. Angiotensin-converting enzyme inhibitor-induced angioedema is unaccompanied by hives, and is caused by the inhibition of enzymatic degradation of tissue bradykinin. Hereditary angioedema, caused by unchecked tissue bradykinin formation, is recognized biochemically by a low plasma C'4 and low quantitative or functional C'1 inhibitor. Progress has now been made in understanding the molecular genetic basis of the two isoforms of this dominantly inherited disease. Recently, a third type of hereditary angioedema has been defined by several groups. Occurring exclusively in women, it is not associated with detectable abnormalities of the complement system. Angioedema caused by a C'1 esterase inhibitor deficiency can also be acquired in several clinical settings, including lymphoma and autoimmune connective tissue disease. It can also occur as a consequence of specific anti-C'1 esterase autoantibodies in some patients. We have reviewed the clinical features, diagnosis, and management of these different subtypes of angioedema.

LEARNING OBJECTIVE

After completing this learning activity, participants should be aware of the classification, causes, and differential diagnosis of angioedema, the molecular basis of hereditary and non-hereditary forms of angioedema, and be able to formulate a pathophysiology-based treatment strategy for each of the subtypes of angioedema.

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.

Coincidence of hereditary angioedema (HAE) with Crohn's disease

A patient with two diseases, based presumably on different immunopathological mechanisms, hereditary angioedema (HAE) and Crohn's disease, was followed for 8 years. For more than three years of this observation period, detailed laboratory data were also available and could be analyzed. Both diseases had severe courses requiring chronic treatment with danazol and sulfasalazine, respectively. During exacerbation of Crohn's disease, the levels of C4 was found to be significantly lower than during the periods free of symptoms of both diseases. This drop was probably due to an impaired C1-inhibitor activity. HAE attacks and acute exacerbation of Crohn's disease never occurred simultaneously. This finding may be a mere chance but may also indicate that the different immunopathological processes underlying HAE and Crohn's disease influence each other.