Humoral response to natural influenza infection in solid organ transplant recipients

Abstract

The humoral immune response of transplant recipients to influenza vaccination has been studied in detail. In contrast, the hemagglutinin inhibiting (HI) antibody response evoked by natural influenza infection and its impact on viral kinetics is unknown. In this prospective, multicenter, cohort study of natural influenza infection in transplant recipients, we measured HI antibody titers at presentation and 4 weeks later. Serial nasopharyngeal viral loads were determined using a quantitative influenza A polymerase chain reaction (PCR). We analyzed 196 transplant recipients with influenza infection. In the cohort of organ transplant patients with influenza A (n = 116), seropositivity rates for strain‐specific antibodies were 44.0% (95% confidence interval [CI] 31.5‐53.2%) at diagnosis and 64.7% (95% CI 55.4‐72.9%) 4 weeks postinfection. Seroconversion was observed in 32.8% (95% CI 24.7‐41.9%) of the cases. Lung transplant recipients were more likely to seroconvert (P = .002) and vaccine recipients were less likely to seroconvert (P = .024). A subset of patients (n = 30) who were unresponsive to prior vaccination were also unresponsive to natural infection. There was no correlation between viral kinetics and antibody response. This study provides novel data on the seroresponse to influenza infection in transplant patients and its relationship to a number of parameters including a prior vaccination status, virologic measures, and clinical variables.

Prevalence and predictors of SARS-CoV-2 antibodies among solid organ transplant recipients with confirmed infection

“…These results are nevertheless consistent with prior studies showing decreased antibody formation among SOT recipients in the setting of either natural infection or vaccination. Among SOT recipients with natural influenza infection, for example, the seroconversion rate of approximately 65% at four weeks is significantly lower than the 82–95% observed in immunocompetent individuals 16 . Similar findings have also been described after vaccination.…”

Humoral Response of Renal Transplant Recipients to the BNT162b2 SARS-CoV-2 mRNA Vaccine Using Both RBD IgG and Neutralizing Antibodies

“…The seroconversion rate after influenza infection was approximately 65% in SOT recipients compared to 82%–85% in immunocompetent individuals. 22 Response to a standard or high dose of influenza vaccine revealed an antibody response in only 56%–79% of 161 SOT recipients, a number significantly lower than that in the general population. 23 A poor antibody response was also reported for hepatitis A, B, and pneumococcal vaccines.…”

Natural influenza infection produces a greater diversity of humoral responses than vaccination in immunosuppressed transplant recipients

“…A key aspect of the immune response includes the development of antibodies directed against specific proteins within the influenza virus 3‐7 . Because of the immunosuppression required to avoid graft rejection, SOT recipients tend to have reduced antibody responses to both natural influenza infection and to vaccination 8,9 . In the vast majority of studies, vaccine response is measured primarily against the hemagglutinin (HA) protein of influenza.…”

“…Based on this, transplant patients generally show variable but suboptimal vaccine immunogenicity and they may still commonly acquire influenza despite vaccination. Less data are available on the humoral immune response to natural infection in transplantation but these also show a limited seroconversion when IgG antibodies are measured using a hemagglutination inhibition assay 8 …”