Human T-lymphotropic virus seroconversion associated with pooled human intravenous immunoglobulin therapy

Impact of IVIG therapy on serologic testing for infectious diseases

Intravenous immunoglobulin (IVIG) is used to treat an increasing number of conditions. The anti-inflammatory and immunomodulatory effects of IVIG can be life-saving; however, recent administration may complicate evaluation for infection. To assess the impact of IVIG therapy on a variety of common viral, bacterial, fungal, and parasitic serologies we prospectively evaluated serologic changes pre- and post-IVIG infusion in 7 participants. The number of new antibody detections ranging from 2 to 5. New detections included positivity for Epstein-Barr virus early D antigen, herpes simplex virus, West Nile virus, cytomegalovirus, and the endemic mycoses Histoplasma and Coccidioides. The greatest number of newly positive serologies was observed in subjects receiving cumulative doses of IVIG in excess of 100 g. Our results illustrate the difficulty in serologic interpretation following IVIG therapy and suggest a dose-response to new positive results. These findings may be a helpful resource to clinicians facing similar circumstances.

False positive viral marker results in blood donors and their unintended consequences

False positive (FP) viral marker results in blood donors continue to pose many challenges. Informing donors of FP results and subsequent deferral can result in stress and anxiety for donors and additional complexity and workload for blood services. Donor management strategies need to balance the requirement to minimise donor anxiety and inconvenience while maintaining sufficiency of supply. Decisions about how and when to inform donors of FP results and determine deferral periods can be difficult as FP results, while often transitory, can take up to several years to resolve. Additional complexities include the interpretation of indeterminate serological confirmatory testing without detectable viral RNA or non-discriminated NAT results with concomitant anti-HBc reactivity - both may be due to FP results, but the former may also represent past infection and the later may represent occult hepatitis B infection. In this review we discuss strategies to minimise indeterminate serological confirmatory results, possible donor deferral policies and the impact on donors when notified of FP results. We also provide some new data from Australia that address the challenge of interpreting non-discriminated NAT results with concomitant anti-HBc reactivity. Ultimately, the challenge is for each blood service to develop appropriate strategies for donor management, taking into account local information and requirements.

IV immunoglobulin confounds JC virus antibody serostatus determination

Objective:

To determine the impact of therapeutic infusion of IV immunoglobulin (IVIg) on John Cunningham virus antibody (JCV Ab) serostatus and level in serum.

Methods:

We carried out a retrospective analysis of serum levels of JCV Ab among STRATIFY-2 trial enrollees from 2 multiple sclerosis centers who were exposed to IVIg during the trial. For the subset of eligible patients, we estimated mean linear trends while on IVIg and after stopping IVIg with a linear mixed-effects model.

Results:

The JCV Ab seropositivity rate in the group of patients that was recently exposed to IVIg was 100%, which is significantly higher than in the IVIg-naive population (58%, p < 0.001). The seropositivity rate in the patient group with remote IVIg exposure was similar to that in the IVIg-naive population (67%, p = 0.68, Fisher exact test). The slope of the linear trend line after stopping IVIg decreased significantly by −0.310 units per 100 days (95% confidence interval, −0.611 to −0.008; p = 0.04).

Conclusions:

Recent IVIg exposure is invariably associated with JCV Ab seropositivity. After stopping IVIg, JCV Ab levels tend to decrease with time, and seroreversion to innately Ab-negative status can occur.