Varicella Zoster Virus Reinfection in a Patient with Refractory Nephrotic Syndrome: A Case Report

Why It Matters

The report underscores a critical vulnerability in rituximab‑treated patients, where impaired antibody production can allow serious viral reinfections, complicating management of underlying diseases such as nephrotic syndrome.

Key Takeaways

• Rituximab caused B‑cell depletion, impairing VZV antibody response
• Six‑year‑old with refractory nephrotic syndrome experienced two VZV infections
• Acyclovir treatment resolved both VZV episodes despite immunosuppression
• Weak IgG titer (3.3) indicated insufficient immunity after first infection
• Case highlights need for VZV prophylaxis in patients receiving rituximab

Pulse Analysis

Varicella‑zoster virus normally confers lifelong immunity after primary infection, a protection that hinges on robust B‑cell‑mediated antibody production. Rituximab, a monoclonal antibody targeting CD20, depletes circulating B cells and is widely used for autoimmune conditions, including refractory nephrotic syndrome. While effective at curbing disease activity, this mechanism can blunt the host's ability to generate new antibodies, leaving patients vulnerable to infections that are otherwise rare, such as VZV reinfection.

In the presented case, a child undergoing rituximab therapy developed VZV twice, each time during periods of profound immunosuppression. The first infection manifested with febrile neutropenia, yet prompt acyclovir therapy achieved viral clearance despite a marginal IgG titer of 3.3. The second episode coincided with an 18th relapse of nephrotic syndrome, illustrating how viral stress can exacerbate underlying renal pathology and necessitate escalated immunosuppressive regimens. This dual challenge highlights the delicate balance clinicians must strike between controlling autoimmune disease and preserving antiviral defenses.

The broader implication is clear: patients receiving B‑cell‑depleting agents should be evaluated for VZV immunity and considered for prophylactic strategies, such as antiviral prophylaxis or vaccination before initiating therapy when feasible. Ongoing monitoring of antibody titers could identify those at risk, enabling early intervention. As rituximab use expands across specialties, integrating infectious risk assessment into treatment protocols will be essential to prevent rare but consequential reinfections.