Peer-reviewed veterinary case report
Large-cell lymphoma in cats after curing feline infectious
By Katharina Buchta et al.·Published in Journal of feline medicine and surgery·2026·View original on Semantic Scholar →
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Original publication title: Large-cell lymphoma in four cats after successful treatment of feline infectious peritonitis with oral GS-441524: a novel clinical observation
- Species:
- cat
Plain-English summary
Four cats developed large-cell lymphoma after being successfully treated for feline infectious peritonitis (FIP) with a medication called GS-441524. The cats, ranging from under 2 years to 13 years old, showed symptoms like weight loss, decreased appetite, and vomiting. They were diagnosed with lymphoma between 81 and 595 days after their FIP treatment, and sadly, they passed away a median of just over two weeks after the lymphoma was diagnosed. This situation highlights a potential long-term complication of FIP treatment, suggesting that cats who recover from FIP may be at risk for developing lymphoma later on.
People also search for: cat lymphoma symptoms · FIP treatment side effects · weight loss in cats after FIP treatment
Abstract
Case series summary Fatal feline infectious peritonitis (FIP), caused by feline coronavirus (FCoV), can now be cured with GS-441524. Only a few unexpected clinical and laboratory observations have been reported with treatment, including lymphocytosis, eosinophilia and long-term persistence of abdominal lymphadenomegaly. Yet immune overstimulation associated with FIP might have negative long-term consequences. This report describes four cases of large-cell lymphoma (LCL) arising within 2 years of FIP diagnosis and successful treatment with legally sourced oral GS-441524 (15 mg/kg q24h), representing an incidence of 2.0% (n = 4/202) in a large treatment cohort. At LCL diagnosis, two cats were aged under 2 years, one was aged 8 years and one was aged 13 years. All cats showed weight loss, three had hyporexia and two had chronic vomiting; all tested negative for feline leukaemia virus and feline immunodeficiency virus. LCL was diagnosed by histology (n = 3) or cytology (n = 1) at 81, 365 (n = 2) and 595 days after FIP diagnosis/treatment start. The cats died a median of 15.5 days after LCL diagnosis. Neither a high FCoV viral load nor FCoV antigen, as determined by semi-quantitative RT-PCR and immunohistochemistry, respectively, was detected in any of the available samples. PCR for antigen receptor rearrangements revealed a monoclonal B-cell population in two cats, supporting a diagnosis of large B-cell lymphoma. Relevance and novel information The incidence of LCL reported here among cats in remission from FIP after legally sourced oral GS-441524 treatment is remarkably high compared with the general feline population. LCL should be considered a potential ‘long-FIP syndrome’ and/or a long-term complication after GS-441524 treatment. The pathogenesis of LCL in this context requires further clarification.
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Search related cases →Original publication on Semantic Scholar: https://www.semanticscholar.org/paper/41807351