Title: Assessing the Safety of Kidney Biopsies Performed on Childhood-onset Systemic Lupus Erythematosus Patients

Background/Purpose:                    

There is very little data in the literature on the rates of adverse events after percutaneous kidney biopsy specifically in childhood-onset lupus (cSLE) patients. In children with and without SLE, studies show that post-biopsy complication rates range from 5 to 23%. Children with SLE often develop anemia, thrombocytopenia, and/or prothrombotic autoantibodies, which may predispose them to biopsy-related complications. Clinicians would benefit tremendously from scientific evidence specifically addressing whether rates of pain or bleeding differ after kidney biopsy in children with SLE.

Methods:

Inclusion criteria: 1) diagnosis of cSLE according to American College of Rheumatology classification criteria, 2) kidney biopsy between January 1, 2011 and December 31, 2015 at Texas Children’s Hospital, and 3) age < 18 years at the time of biopsy. Our cohort included 107 lupus biopsies (77% female, 50% Hispanic, 26% African American, 16% Caucasian, 5% Asian, 2% mixed, 1% Vietnamese). Routine post-biopsy care of cSLE patients includes overnight observation in the hospital. Charts were reviewed for biopsy-related complications both during and after procedures performed by either nephrologists or radiologists. Nephrologists performed 87% and radiologists 13% were performed by radiologists.  Procedural complications were classified using the Society of Interventional Radiology (SIR) scale (class A and B minor complications, classes C, D, E, and F major complications). Anesthesia complications were classified using the Surgical Apgar Score (SAS).

Results:

The rate of major complications was 12%. Table 1 below shows the most common kidney biopsy-related events. No anesthesia complications were observed. There were no deaths, nephrectomies, or permanent disabilities, and >50% of  major complications were class C. The most frequent complications were pain (71%) and gross hematuria (12%). One patient required angiography to correct the bleeding and 5 patients had prolonged hospitalization due to biopsy-related complication.

Conclusion:

Percutaneous kidney biopsies are a relatively safe procedure to perform in cSLE patients. Although small perinephric hematomas are common, most are asymptomatic or resolve with acetaminophen alone. The need for IV narcotics to treat pain in a significant portion of our patients justifies the practice of overnight observation following kidney biopsy for this indication. As in biopsies performed for non-SLE indications, the rate of major complications is low.

Table 1: Event Rates following Percutaneous Kidney Biopsy in Children with Systemic Lupus Erythematosus (n=107)

*an additional hospitalization beyond 23-hour observation