CMV-associated collapsing focal segmental glomerulosclerosis after kidney transplant in a pediatric patient

Abstract

Background: Cytomegalovirus (CMV) is a significant cause of morbidity among immunocompromised patients who have undergone kidney transplantation and is known to rarely induce collapsing focal segmental glomerulosclerosis (FSGS) among adults.

Methods: We present the first reported case of CMV-induced collapsing FSGS in a pediatric patient after kidney transplant.

Results: Our patient underwent a deceased donor kidney transplant due to end-stage renal disease secondary to lupus nephritis. Approximately 4 months after transplantation, he developed signs of worsening kidney function in the setting of CMV viremia and was found to have collapsing features of FSGS on kidney transplant biopsy. He was managed with a prompt escalation of antiviral therapy along with a reduction of immunosuppression and recovered without significant complication. At follow-up, he continued to have undetectable CMV titers, creatinine within normal limits, and no significant proteinuria.

Conclusion: This report demonstrates CMV as a cause of collapsing FSGS and should be considered among pediatric transplant recipients who present with acute kidney injury, as should early assessment of APOL1 genetic status in both donor and recipient.

Keywords: collapsing focal segmental glomerulosclerosis; cytomegalovirus; kidney transplantation; pediatrics.

Figure 1:

Serum creatinine level and blood CMV PCR titers peaking on postoperative day #128, indicating the close temporal relationship between rising CMV titer and elevation and subsequent decline of serum creatinine from acute kidney injury.

Figure 2:

Inverse association between serum albumin and serum creatinine during our patient’s acute kidney injury in the setting of elevated CMV PCR titers on postoperative day #128. Albumin is rapidly wasted during acute kidney injury due to basement membrane damage resulting in protein loss, likely due to collapsing FSGS features.

Figure 3:

Histologic findings of the kidney allograft biopsy (A) A glomerulus with collapsing features characterized by segmental collapse of the glomerular tuft accompanied by prominence of glomerular epithelium (Jones methenamine silver, original magnification ×400) (B) Focal tubulointerstitial inflammation (Hematoxylin and Eosin, original magnification ×200) (C) Electron microscopic image showing extensive foot process effacement (electron microscopy, original magnification ×5000)