Where we are with acquired angioedema due to C1 inhibitor deficiency: A systematic literature review

Angioedema due to Acquired C1-Inhibitor Deficiency Without Hematological Condition: A Multicenter French Cohort Study of 34 Patients

BACKGROUND

Angioedema (AE) due to acquired C1-inhibitor deficiency (AAE-C1-INH) is a rare disease associating recurrent edema of the mucosa and skin. Several underlying diseases have been reported, mainly lymphoproliferative diseases and monoclonal gammopathy. However, 15% to 20% of patients never exhibit such a hematological condition.

OBJECTIVE

To analyze specific features of patients with AAE-C1-INH without a hematological condition.

METHODS

This is a multicenter, retrospective cohort study of patients with AAE-C1-INH without a hematological condition included from January 1999 to May 2024 in the French national CREAK (Centre de reference des angioedèmes à kinine) registry. The clinical and biological characteristics of patients were detailed and then compared with those of patients with AAE-C1-INH associated with lymphoid hemopathies or monoclonal gammopathy.

RESULTS

Thirty-four patients were included. All patients displayed a functional C1-INH below 50% of the reference value, 26 (76%) also had a decreased C1-INH antigen level, and 26 (76%) displayed anti-C1-INH antibodies. After a median follow-up of 65 months, 4 (12%) patients were in spontaneous complete remission of AE; 15 (44%) were in complete response under long-term prophylactic treatment. Compared with 75 patients with lymphoma-associated AAE-C1-INH, patients with AAE-C1-INH without a hematological condition displayed a higher incidence of anti-C1-INH antibodies and received more frequently symptomatic or prophylactic treatment with a lower remission rate at last follow-up. Clinical and biological features of patients with AAE-C1-INH without a hematological condition were similar to those of 30 patients with monoclonal gammopathy-associated AAE-C1-INH.

CONCLUSIONS

AAE-C1-INH without a hematological condition displays a different clinical and biological presentation from lymphoma-associated AAE-C1-INH. No autoimmune disease was identified. Unlike rituximab, long-term prophylaxis seems to prevent AE attacks among these patients.

Angioedema due to Acquired C1-Inhibitor Deficiency Associated With Monoclonal Gammopathies of Undetermined Significance Characteristics of a French National Cohort

BACKGROUND

No specific description of monoclonal gammopathies of undetermined significance (MGUS)-associated angioedema due to acquired C1 inhibitor deficiency (AAE-C1-INH) has been reported yet.

OBJECTIVE

To describe the biological and clinical characteristics, evolution, and response to treatment of MGUS-associated AAE-C1-INH.

MATERIALS AND METHODS

We conducted a French national retrospective observational study on MGUS-associated acquired angioedema spanning a 30-year period.

RESULTS

Forty-one patients with MGUS-associated AAE-C1-INH at diagnosis were included; 68% displayed anti-C1-INH antibodies. The monoclonal component was an IgM in 24 patients, IgG in 11, and IgA in 6 patients. The mean age at first angioedema attack was 63 years (standard deviation [SD] = 13 years) and at diagnosis 66 years (SD = 11 years). A total of 88% patients benefited from acute attack treatments, and 77% from long-term prophylaxis, either danazol, tranexamic acid, or lanadelumab. Median follow-up was 7 years, during which 14 patients (33%) evolved into well-defined malignant hemopathies. Fifty percent of patients were given a hematological treatment, either rituximab alone, indicated by recurrent attacks of angioedema in patients with AAE-C1-INH with anti-C1-INH antibodies, or validated combinations of chemotherapies, indicated by evolution into a lymphoma in 7 patients and a myeloma in 3 patients. Fifteen patients (35%) were in clinical complete remission of angioedema at last visit, of whom 60% had an undetectable serum monoclonal immunoglobulin.

CONCLUSIONS

Complete remission of AAE-C1-INH is correlated to complete remission of the underlying hematological malignancy, as defined by an undetectable serum monoclonal immunoglobulin. In our MGUS-associated acquired angioedema cohort, we recorded an incidence of evolution into hematological malignancy of 4% per patient-year. It is therefore crucial to conduct full hematological workup during follow-up at an annual rate, and earlier if AAE relapses or if acute attack frequency increases.

Acute Abdominal Pain as the Initial Presentation of an Acquired C1 Inhibitor Deficiency

Introduction

Acquired angioedema (AAE), a rare cause of adult-onset non-urticarial mucocutaneous angioedema, can present as acute abdomen, a frequent complaint in the emergency room (ER), often leading to unnecessary and potentially harmful procedures.

Case Presentation

We report a 47-year-old hypertense male, controlled with an angiotensin converting enzyme inhibitor (ACEI), who presented in the ER with progressively worsening abdominal pain, nausea, and vomiting, and a radiologic workup revealing small intestine thickening, initially diagnosed with ACEI-induced angioedema. However, further investigation revealed low serum levels of C4, C1q, and C1 inhibitors, with an abnormal function of the latter, favoring the diagnosis of AAE instead. The frequent association of this condition with lymphoproliferative disorders encouraged further studies, which unveiled a monoclonal gammopathy IgM/Kappa, representing an increased risk of Waldenström macroglobulinemia, non-Hodgkin lymphoma, and multiple myeloma.

Discussion

AAE should be regarded as an important differential diagnosis in patients presenting with acute abdomen in the ER, especially when more common causes are excluded. A correct and early diagnosis may represent a chance for a better prognosis of underlying diseases.

TEMPI syndrome: A clinical, light-microscopic and phenotypic evaluation with review of the literature

BACKGROUND AND OBJECTIVES

TEMPI (telangiectasias, elevated erythropoietin and erythrocytosis, monoclonal gammopathy, perinephric fluid collections, and intrapulmonaryshunting) syndrome is a rare multisystemic disease classified as a monoclonal gammopathy of cutaneous significance. The pathogenesis and etiology of TEMPIare not well known because of the rarity of this disorder. Although telangiectasias are the hallmark of this syndrome, skin biopsies are rarely performed. We aim to further characterize TEMPI syndrome through the evaluationof a skin biopsy.

METHODS

We reviewed the histopathology and immunophenotypic profile of a skin biopsy from a 53-year-oldwoman diagnosed with TEMPI syndrome. Other components of her syndromic complex included an IgA myeloma, elevated vascular endothelial growth factor (VEGF), and erythrocytosis.

RESULTS

A biopsy showed prominent vascular ectasia with some degree of microvascular basement membranezone thickening. Our patient had a reduction in neoplastic plasma cell burdenand clearing of her telangiectasias following myeloma directed treatment.

CONCLUSIONS

TEMPI can beviewed as a reactive vascular paraneoplastic syndrome in the setting of a plasma cell dyscrasia. Elaboration of VEGF from neoplastic plasma cells is likely pathogenetically implicated and appears to be a common link that explains other vascular lesions associated with monoclonal gammopathy syndromes.

Acquired Angioedema Associated with Lymphoproliferative Disorders

Introduction

Acquired angioedema due to C1 esterase inhibitor deficiency (C1INH-AAE) is most associated with lymphoproliferative disorders (LPDs), particularly low-grade B-cell subtypes. The condition remains under-recognized with long diagnostic delays due to various challenges including a lack of awareness of the condition.

Case Presentation

We discuss 4 cases of C1INH-AAE associated with low-grade B-cell LPDs, including various diagnostic and management challenges. As our cases illustrate, constitutional symptoms or overt manifestations of LPD at diagnosis are often absent. Hence, a comprehensive multimodal approach to screening for an underlying B-LPD is important when a diagnosis of acquired angioedema is made. Levels of complement C4, C1q, and C1INH are useful for diagnosing C1INH-AAE and for monitoring disease activity. Changes in these parameters may also indicate relapse of the underlying hematological malignancy. Treating the underlying disorder is important as this commonly leads to clinical improvement with decreased episodes of angioedema and normalization of complement studies.

Conclusion

Awareness of C1INH-AAE can lead to an early diagnosis of hematological malignancies. The absence of constitutional symptoms emphasizes the need for a comprehensive multimodal approach to screening for LPD in C1INH-AAE. C4, C1INH level, and function are useful for monitoring disease activity.

Angioedema in the Absence of C1 Esterase Inhibitor Deficiency in a Young Patient With Anti-dsDNA Negative Lupus Nephritis

Hereditary angioedema (HAE) is an autosomal dominant condition marked by a lack of functioning C1 esterase inhibitor (C1-INH). In contrast, acquired angioedema (AAE) due to a deficiency of C1 esterase inhibitor (AAE-C1-INH) may be the manifestation of an underlying lymphoproliferative, neoplastic, or autoimmune condition. Both are potentially fatal. The C1q protein is normal in HAE but low in AAE. A third mechanism has been reported to cause angioedema, especially in systemic lupus erythematosus (SLE) patients. AAE, which happens in association with SLE, may respond well to steroids. Here we present a case of AAE in a young female with SLE that led to upper airway compromise, requiring endotracheal intubation. Early detection and treatment of such cases can lead to an outstanding prognosis by preventing airway compromise and anoxic brain injury. Even though it is a condition of either very young or middle-aged patients, practitioners must be aware of this uncommon disease linked with SLE in adolescents and young adults.

[Angioedema in the emergency department]

Acute angioedema is mostly found in the head and neck region. Therefore, it can be life threatening by potentially endangering air way patency. Pathophysiologically angioedemas can be divided into mast cell-mediated or bradykinin-mediated forms. Differentiation is essential due to the different therapeutic strategies. In cases of doubt, initial therapy with adrenalin, antihistamines, and glucocorticoids should be initiated. This initial emergency treatment is comparable to the treatment of allergic reactions. For diagnosed or suspected hereditary angioedema, specific treatments are available. For drug-associated forms, immediate and life-long cessation of the medication is crucial. In the emergency situation, diagnosis can only be based on medical history and clinical symptoms. Recognition of impending airway obstruction and securing the airway is of highest priority; final diagnosis must be confirmed later.

Presentation of an extraordinary colic: abdominal pain as the first and only utterance of an acquired C1-inhibitor deficiency

C1-inhibitor deficiency is a rare disease which incorporates acute self-limiting intermittent swelling of the subcutaneous tissue and mucous membranes. Attacks most frequently affect the face and/or the upper airway. Isolated angioedema of the small bowel is an uncommon manifestation and often accompanied by diagnostic delay. In the present case, abdominal pain turned out to be the first and only utterance of an acquired C1-inhibitor deficiency, secondary to a splenic marginal zone lymphoma. Imaging showed wall thickening of the small intestine, ascites and splenomegaly. The abdominal pain and intestinal wall thickening with surrounding ascites on imaging spontaneously resolved each episode within 2-3 days. Gastrointestinal manifestations of angioedema may mimic an acute abdomen, and subsequently one-third of these patients undergo unnecessary surgery prior to a definite diagnosis. This emphasises the importance of considering the diagnosis in case of an 'extraordinary colic'.