Small bowel angioedema due to acquired C1 inhibitor deficiency: a case report and overview

Monoclonal gammopathies of clinical significance (MGCS): In pursuit of optimal treatment

Monoclonal gammopathy of clinical significance (MGCS) represents a new clinical entity referring to a myriad of pathological conditions associated with the monoclonal gammopathy of undetermined significance (MGUS). The establishment of MGCS expands our current understanding of the pathophysiology of a range of diseases, in which the M protein is often found. Aside from the kidney, the three main organ systems most affected by monoclonal gammopathy include the peripheral nervous system, skin, and eye. The optimal management of these MGUS-related conditions is not known yet due to the paucity of clinical data, the rarity of some syndromes, and limited awareness among healthcare professionals. Currently, two main treatment approaches exist. The first one resembles the now-established therapeutic strategy for monoclonal gammopathy of renal significance (MGRS), in which chemotherapy with anti-myeloma agents is used to target clonal lesion that is thought to be the culprit of the complex clinical presentation. The second approach includes various systemic immunomodulatory or immunosuppressive options, including intravenous immunoglobulins, corticosteroids, or biological agents. Although some conditions of the MGCS spectrum can be effectively managed with therapies aiming at the etiology or pathogenesis of the disease, evidence regarding other pathologies is severely limited to individual patient data from case reports or series. Future research should pursue filling the gap in knowledge and finding the optimal treatment for this novel clinical category.

Abdominal hereditary angio-oedema caught on magnetic resonance imaging

A 17-year-old woman presented with a 3-year history of recurrent, severe abdominal pain with spontaneous resolution within a few days. An ultrasound revealed nothing more than free fluid within the pelvis. An MRI of the small bowel was done within 24 hours of abdominal pain onset, which revealed extensive submucosal oedema associated with moderate volume ascites. A repeat MRI of the small bowel after 72 hours showed near-complete resolution of these changes. Checking C1 inhibitor levels confirmed a diagnosis of hereditary angio-oedema with an abdominal presentation. This is a rare cause of recurrent abdominal pain and, to our knowledge, the first case in which MR images have been obtained during and after an acute attack.

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

Acquired angioedema due to C1 inhibitor deficiency (C1-INH-AAE) is a rare disease characterized by adult-onset recurrent non-urticarial angioedema with low levels of C1-INH. It is associated with lymphoproliferative disorders, and treatments are off-label with variable success. We conducted a systematic literature review to include patients with C1-INH-AAE identified in PubMed and Embase databases between January 2006 and February 2021. Clinical features of these patients were summarized, and factors associated with disease remission were explored. A total of 121 patients were included in the current study with a median age at diagnosis of 64 years and 45.5% being male. An associated disease was recorded in 94 patients (77.7%), and lymphoproliferative disorder was the most reported (59/94, 62.8%). Anti-C1-INH autoantibodies were present in 45 of 71 patients (63.4%). Factors impacting disease remissions included age (odds ratio [OR] 0.951, 95% confidence interval [CI] 0.909-0.994, p = 0.027), male (OR 0.327, 95% CI 0.124-0.866, p = 0.025), presence of monoclonal gammopathy (OR 0.133, 95% CI 0.041-0.429, p = 0.001), requirement of specific on-demand treatment (OR 0.216, 95% CI 0.066-0.709, p = 0.012) and rituximab use (OR 2.865, 95% CI 1.038-7.911, p = 0.042). A total of nine patients (7.4%) died at last follow up and most were unrelated to C1-INH-AAE. Our results imply that C1-INH-AAE is primarily associated with underlying B or plasma cell abnormalities, and clone-directed therapies could be promising options for its long-term management.

Hereditary angioedema: A rare cause of recurrent abdominal pain

Hereditary angioedema is a rare autosomal dominant inherited disease which is characterized by an episodic, self-limiting increase in vascular permeability. Symptoms commonly involve in nonpitting, nonpruritic skin swellings. We present a case of hereditary angioedema. The patinets complained of a recurrent abdominal pain without accompanying skin swelling whose diagnosis was delayed nearly 20 years and accepted an unnecessary surgery. According to the decreased serum C1-inhibitor and C4 concentration, the patient was finally diagnosed with hereditary angioedema type I. After treatment with danazole, the patient reported a significant decrease in the frequency of attacks and the severity of pain. HAE is a rare cause of abdominal pain, however it needs to be taken as one of the differential diagnosis of various acute abdomens in order to avoid unnecessary surgeries.

C1-esterase inhibitor deficiency in pediatric heart transplant recipients: incidence and findings on ultrasound

BACKGROUND

Acquired angioedema of the bowel caused by a deficiency of C1-esterase inhibitor can lead to severe abdominal pain with sudden onset, mimicking an acute surgical abdomen. In contrast to hereditary angioedema, which usually manifests in childhood, acquired angioedema is broadly recognized to affect people older than 40 years.

OBJECTIVE

To determine the incidence of acquired angioedema in a cohort of pediatric heart transplant recipients and assess imaging findings on ultrasonography.

MATERIALS AND METHODS

A cohort of 207 children and adolescents who had undergone heart transplantation were assessed at regular follow-up examinations for incidence of acquired angioedema. All patients received ACE inhibitors and immune inhibitors. Control examinations carried out in 3-month intervals included history, assessment of clinical symptoms, physical examination, US of the abdomen and laboratory blood analysis. In addition, if clinical symptoms were newly encountered, children were admitted between regularly scheduled intervals. We analyzed results of abdominal US for pathological findings of the bowel, and we assessed imaging findings in children diagnosed with acquired angioedema.

RESULTS

Acquired angioedema was diagnosed in 3/207 patients (2 girls ages 16 and 17 years and 1 boy age 9 months). These children presented with sudden onset of severe abdominal pain. The bowel wall was thickened in the presence of ascites. After a mean of 72 h, abdominal pains resolved. Thickening of bowel loops dissolved and ascites disappeared.

CONCLUSION

Single episodes of acquired angioedema were encountered in 1.4% of our series of pediatric heart transplant recipients. Radiologists should be familiar with this disease so they can diagnose it on US imaging.