Reply to Comment on "An Unusual Case of Acquired Angioedema and Monoclonal Gammopathy of Renal Significance in a Middle-Aged Caucasian Female".

We sincerely thank Dr Andrew Whyte, who keenly reviewed our case report and came up with critical reasoning to justify his thoughts and critique with regard to our published article, "An Unusual Case of Acquired Angioedema and Monoclonal Gammopathy of Renal Significance in a Middle-Aged Caucasian Female." We agree with the author that hypocomplementemic urticarial vasculitis can be a reasonable contender as a diagnosis in this case. There are indeed some features in this case that do not entirely fit either classic presentation of acquired angioedema or hypocomplementemic urticarial vasculitis. Both diseases being equally rare, we tried to focus on the association of proliferative glomerulonephritis with angioedema-like features in this patient and considered acquired angioedema as the unifying diagnosis.

An Unusual Case of Acquired Angioedema and Monoclonal Gammopathy of Renal Significance in a Middle-Aged Caucasian Female.

Acquired angioedema due to deficiency of C1 esterase inhibitor is also called acquired angioedema and is abbreviated as C1INH-AAE. It is a rare syndrome of recurrent episodes of angioedema, without urticaria, and in some patients, it is associated with B-cell lymphoproliferative disorders. Kidney involvement is rare in this condition. The monoclonal immunoglobulin secreted by a nonmalignant or premalignant B-cell or plasma cell clone, causing renal damage that represents a group of disorders which are termed as monoclonal gammopathy of renal significance (MGRS). In this article, we report a rare case of acquired C1 esterase deficiency angioedema and acute kidney injury with renal biopsy-proven MGRS. We present a 64-year-old Caucasian woman who presented with 2 weeks of recurring urticaria and new onset of acute kidney injury. She was diagnosed with monoclonal gammopathy-associated proliferative glomerulopathy through kidney biopsy, and serological workup came back positive for C1 esterase deficiency, implying acquired angioedema. Acquired angioedema is a rare disease with systemic involvement. Recurrent allergic manifestations and acute kidney injury should prompt MGRS as a differential.