aHUS May be Associated With Heart Disease, Case Report Shows

In some patients, atypical hemolytic uremic syndrome (aHUS) may be associated with heart disease, a case report study highlights.

The case report study, “Atypical Hemolytic Uremic Syndrome Presenting as Acute Heart Failure — A Rare Presentation: Diagnosis Supported by Skin Biopsy,” was published in the Journal of Investigative Medicine High Impact Case Reports.

aHUS is caused by the progressive destruction of red blood cells because of a malfunction of the complement system — a set of more than 50 blood proteins that form part of the body’s immune defenses. The most common manifestations of aHUS include anemia, low platelet count (thrombocytopenia), and kidney failure.

However, some patients may also have nervous system involvement and, in rare cases, heart involvement.

In this case report study, authors described the clinical case of a patient with aHUS associated with heart disease.

The 24-year-old man with no history of heart disease arrived at the hospital with acute shortness of breath.

Clinical examination revealed the patient was undergoing acute heart and kidney failure. Lab tests showed he had low platelet count, low haptoglobin levels, low activity of complement proteins (C3, C4, and CH50), hematuria (blood in urine) and proteinuria (proteins in urine). Based on his clinical presentation, physicians suspected the patient had aHUS.

To confirm their suspicions, clinicians performed a skin biopsy of a rash on the patient’s arm, avoiding the standard kidney biopsy because of the severe thrombocytopenia the patient was experiencing.

Skin biopsy analyses found signs of thrombotic microangiopathy (clotting of small blood vessels), confirming the diagnosis of aHUS. As a result, the patient was advised to start complement blockade therapy. However, treatment was not initiated immediately because of the patient’s concerns regarding the safety of immunotherapy drugs and his desire to get a second opinion.

In the meantime, the patient went into spontaneous disease remission and was discharged from the hospital once his heart and kidney function had normalized. He was also instructed to visit a higher- level medical center to be monitored for any disease relapse.

“Our case highlights a relatively rare association between aHUS and [heart] involvement, and the use of skin biopsy to support diagnosis of aHUS in patients who cannot undergo [kidney] biopsy because of thrombocytopenia,” the authors wrote.

“Since myocardial infarction and heart failure are life-threatening complications, early clinical suspicion leading to prompt diagnosis and initiation of therapy are of utmost importance to improve survival and long-term prognosis [of these patients],” they added.