Human Metapneumovirus Infection Linked to Lymphopenia and Corticosteroid Use After Allogeneic HCT

Lymphopenia and corticosteroid use showed significant links to human metapneumovirus (hMPV) infection and its severity in recipients of allogeneic hematopoietic stem cell transplantation (allo-HCT) in a study. The study findings were reported in The Journal of Infectious Diseases.

The study investigators also observed that the epidemiology of hMPV infection in these patients appeared to reflect patterns seen with the general population, even in the setting of guidance given to patients and caregivers on preventing infection transmission.

The study was a retrospective analysis conducted at centers across Europe. It included patients who were children and adults, who had undergone allo-HCT, and who experienced respiratory symptoms from a period including January 1, 2012, to December 30, 2019.

The study’s primary objective was an evaluation of epidemiological and clinical features of respiratory disease in recipients of allo-HCT who developed hMPV infection. Infections were divided into upper respiratory tract disease (URTD) and lower respiratory tract disease (LRTD). Risk factors for various outcomes with infection were also investigated.

There were 428 patients in the study, with adults representing 93% of the study population. Across the study population overall, 438 hMPV infections occurred during the study period. URTD accounted for 60% of infections, while LRTD accounted for 40%.

Compared with URTD, cases of possible or proven LRTD tended to be identified sooner after allo-HCT. Rates of lymphopenia and neutropenia were also higher with LRTD, as were the rates of use of corticosteroids or ribavirin, among other characteristics. Independent factors associated with developing LRTD included lymphopenia and the use of corticosteroids at a dose of >30 mg/d.

Mortality rates at day 30 following hMPV detection were 2% in patients who had URTD, 12% in patients considered to have possible LRTD, and 21% in patients with proven LRTD. Lymphopenia was the sole independent risk factor identified for mortality with LRTD by day 30 in this population. At day 90, overall survival rates were 96.2% with URTD, 80.8% with possible LRTD, and 62.8% with proven LRTD.

The study investigators concluded that among patients in this study who had undergone allo-HCT, lymphopenia and the use of corticosteroids were associated with greater hMPV infection severity. “Overall mortality was high in recipients with proven LRTD, indicating that these infections can have moderate to severe direct and indirect consequences in a significant proportion of cases,” the investigators wrote in their report.

Disclosures: Some study authors declared affiliations with biotech, pharmaceutical, or device companies. Please see the original reference for a full list of disclosures.

Reference

Piñana JL, Tridello G, Xhaard X, et al; on behalf of the Infectious Diseases Working Party of the European Society for Blood and Marrow Transplantation and Infectious Complications Subcommittee of the Spanish Hematopoietic Stem Cell Transplantation and Cell Therapy Group (GETH-TC). Upper and/or lower respiratory tract infection caused by human metapneumovirus after allogeneic hematopoietic stem cell transplantation. J Infect Dis. Accepted manuscript. Published online July 13, 2023. doi:10.1093/infdis/jiad268