{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,8]],"date-time":"2026-06-08T13:43:15Z","timestamp":1780926195184,"version":"3.54.1"},"reference-count":31,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2022,8,4]],"date-time":"2022-08-04T00:00:00Z","timestamp":1659571200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pathogens"],"abstract":"<jats:p>Feline infectious peritonitis (FIP) remains a major diagnostic and treatment challenge in feline medicine. An ineffective immune response is an important component of FIP pathophysiology; hence treatment with an immune stimulant such as Polyprenyl Immunostimulant\u2122 (PI), which enhances cell-mediated immunity by upregulating the innate immune response via Toll-like receptors, is a rational approach. Records of cats with FIP treated with PI orally for over 365 days were retrospectively studied. Of these cats (n = 174), records were obtained for n = 103 cats with appropriate clinical signs and clinical pathology. Of these, n = 29 had FIP confirmed by immunohistochemistry (IHC) or reverse transcription polymerase-chain-reaction (RT-PCR). Most of the cats (25\/29; 86%) had non-effusive FIP, and only 4\/29 cats (14%) had effusive FIP. The mean survival time (MST) was 2927 days (eight years); with 55% of the cats (16\/29) still being alive at the time data collection, and 45% (13\/29) having died. A persistently low hematocrit plus low albumin:globulin (A:G) ratio, despite treatment, was a negative prognostic indicator. It took a mean of ~182 days and ~375 days, respectively, for anemia and low A:G ratio to resolve in the cats that presented with these laboratory changes. This study shows that PI is beneficial in the treatment of FIP, and more studies are needed to establish the best protocols of use.<\/jats:p>","DOI":"10.3390\/pathogens11080881","type":"journal-article","created":{"date-parts":[[2022,8,5]],"date-time":"2022-08-05T02:12:39Z","timestamp":1659665559000},"page":"881","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":16,"title":["Retrospective Survival Analysis of Cats with Feline Infectious Peritonitis Treated with Polyprenyl Immunostimulant That Survived over 365 Days"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4300-8534","authenticated-orcid":false,"given":"Petra","family":"\u010cern\u00e1","sequence":"first","affiliation":[{"name":"Department of Clinical Sciences, Colorado State University, Fort Collins, CO 80523, USA"},{"name":"Small Animal Clinic, The University of Veterinary Sciences Brno, 612 42 Brno, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ashley","family":"Ayoob","sequence":"additional","affiliation":[{"name":"Critical Care and Internal Medicine Services, Blue Pearl Veterinary Partners, Naples, FL 34112, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Caroline","family":"Baylor","sequence":"additional","affiliation":[{"name":"College of Liberal Arts and Sciences, University of Florida, Gainesville, FL 32601, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Erin","family":"Champagne","sequence":"additional","affiliation":[{"name":"Independent Researcher, Columbia, MO 65211, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sandra","family":"Hazanow","sequence":"additional","affiliation":[{"name":"Seven Hills Veterinary Hospital, San Francisco, CA 94131, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Robert E.","family":"Heidel","sequence":"additional","affiliation":[{"name":"Department of Surgery, University of Tennessee Graduate School of Medicine, Knoxville, TN 37920, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kimberly","family":"Wirth","sequence":"additional","affiliation":[{"name":"Wisconsin Veterinary Referral Center, Waukesha, WI 53188, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alfred M.","family":"Legendre","sequence":"additional","affiliation":[{"name":"Small Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2088-503X","authenticated-orcid":false,"given":"Dani\u00e8lle A.","family":"Gunn-Moore","sequence":"additional","affiliation":[{"name":"The Royal (Dick) School of Veterinary Studies and The Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian EH25 9RG, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,8,4]]},"reference":[{"key":"ref_1","first-page":"157","article-title":"Some important disorders of cats","volume":"53","author":"Holzworth","year":"1963","journal-title":"Cornell Vet."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"225","DOI":"10.1016\/j.jfms.2008.09.008","article-title":"A review of feline infectious peritonitis virus infection: 1963\u20132008","volume":"11","author":"Pedersen","year":"2009","journal-title":"J. Feline Med. Surg."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"321","DOI":"10.1354\/vp.42-3-321","article-title":"Morphologic features and development of granulomatous vasculitis in feline infectious peritonitis","volume":"42","author":"Kipar","year":"2005","journal-title":"Vet. Pathol."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Sherding, R.G. (2006). Feline Infectious Peritonitis (Feline Coronavirus). Saunders Manual of Small Animal Practice, Elsevier.","DOI":"10.1016\/B0-72-160422-6\/50012-7"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"348","DOI":"10.1177\/1098612X15586209","article-title":"Clinical and laboratory features of cats with feline infectious peritonitis\u2014A retrospective study of 231 confirmed cases (2000\u20132010)","volume":"18","author":"Riemer","year":"2016","journal-title":"J. Feline Med. Surg."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"209","DOI":"10.1136\/vr.129.10.209","article-title":"Feline infectious peritonitis: A review of clinicopathological changes in 65 cases, and a critical assessment of their diagnostic value","volume":"129","author":"Sparkes","year":"1991","journal-title":"Vet. Rec."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"74","DOI":"10.1016\/j.jfms.2010.09.014","article-title":"Clinicopathological findings and disease staging of feline infectious peritonitis: 51 cases from 2003 to 2009 in Taiwan","volume":"13","author":"Tsai","year":"2011","journal-title":"J. Feline Med. Surg."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"666","DOI":"10.1111\/j.1751-0813.2005.tb13044.x","article-title":"Clinicopathological findings associated with feline infectious peritonitis in Sydney, Australia: 42 cases (1990\u20132002)","volume":"83","author":"Norris","year":"2005","journal-title":"Aust. Vet. J."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"205","DOI":"10.1016\/S0165-2427(98)00155-X","article-title":"Some aspects of humoral and cellular immunity in naturally occuring feline infectious peritonitis","volume":"65","author":"Paltrinieri","year":"1998","journal-title":"Vet. Immunol. Immunopathol."},{"key":"ref_10","first-page":"345","article-title":"An appraisal of the value of laboratory tests in the diagnosis of feline infectious peritonitis","volume":"30","author":"Sparkes","year":"1994","journal-title":"Am. Anim. Hosp. Assoc. (USA)"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"14122","DOI":"10.1128\/JVI.79.22.14122-14130.2005","article-title":"Acquisition of macrophage tropism during the pathogenesis of feline infectious peritonitis is determined by mutations in the feline coronavirus spike protein","volume":"79","author":"Rottier","year":"2005","journal-title":"J. Virol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2483","DOI":"10.1007\/s00705-005-0598-6","article-title":"Replication of feline coronaviruses in peripheral blood monocytes","volume":"150","author":"Dewerchin","year":"2005","journal-title":"Arch. Virol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1016\/j.tvjl.2014.04.017","article-title":"An update on feline infectious peritonitis: Virology and immunopathogenesis","volume":"201","author":"Pedersen","year":"2014","journal-title":"Vet. J."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"505","DOI":"10.1177\/0300985814522077","article-title":"Feline infectious peritonitis: Still an enigma?","volume":"51","author":"Kipar","year":"2014","journal-title":"Vet. Pathol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1036","DOI":"10.1128\/JVI.79.2.1036-1044.2005","article-title":"Natural history of a recurrent feline coronavirus infection and the role of cellular immunity in survival and disease","volume":"79","year":"2005","journal-title":"J. Virol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1016\/j.jcpa.2018.11.001","article-title":"Inflammatory mediators in the mesenteric lymph nodes, site of a possible intermediate phase in the immune response to feline coronavirus and the pathogenesis of feline infectious peritonitis?","volume":"166","author":"Malbon","year":"2019","journal-title":"J. Comp. Pathol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"81","DOI":"10.1186\/s13567-018-0578-y","article-title":"Characterization of peritoneal cells from cats with experimentally-induced feline infectious peritonitis (FIP) using RNA-seq","volume":"49","author":"Watanabe","year":"2018","journal-title":"Vet. Res."},{"key":"ref_18","unstructured":"Kuritz, T.K. (2018). Methods and Compositions for Modulation of Innate Immunity. (9,872,867), U.S. Patent."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"24","DOI":"10.3389\/fvets.2017.00024","article-title":"Polyprenyl immunostimulant in Feline rhinotracheitis: Randomized Placebo-controlled experimental and Field safety studies","volume":"4","author":"Legendre","year":"2017","journal-title":"Front. Vet. Sci."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"624","DOI":"10.1016\/j.jfms.2008.12.002","article-title":"Effect of Polyprenyl Immunostimulant on the survival times of three cats with the dry form of feline infectious peritonitis","volume":"11","author":"Legendre","year":"2009","journal-title":"J. Feline Med. Surg."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"7","DOI":"10.3389\/fvets.2017.00007","article-title":"Polyprenyl immunostimulant treatment of cats with presumptive non-effusive feline infectious peritonitis in a field study","volume":"4","author":"Legendre","year":"2017","journal-title":"Front. Vet. Sci."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"851","DOI":"10.1111\/j.1939-1676.2004.tb02632.x","article-title":"Prevalence of diseases of the spinal cord of cats","volume":"18","author":"Vite","year":"2004","journal-title":"J. Vet. Intern. Med."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"38","DOI":"10.1016\/S1090-0233(03)00055-8","article-title":"Changes in some acute phase protein and immunoglobulin concentrations in cats affected by feline infectious peritonitis or exposed to feline coronavirus infection","volume":"167","author":"Giordano","year":"2004","journal-title":"Vet. J."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"271","DOI":"10.1177\/1098612X19825701","article-title":"Efficacy and safety of the nucleoside analog GS-441524 for treatment of cats with naturally occurring feline infectious peritonitis","volume":"21","author":"Pedersen","year":"2019","journal-title":"J. Feline Med. Surg."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1698","DOI":"10.1099\/vir.0.020214-0","article-title":"Sites of feline coronavirus persistence in healthy cats","volume":"91","author":"Kipar","year":"2010","journal-title":"J. Gen. Virol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1685","DOI":"10.1099\/vir.0.81692-0","article-title":"Feline infectious peritonitis virus-infected monocytes internalize viral membrane-bound proteins upon antibody addition","volume":"87","author":"Dewerchin","year":"2006","journal-title":"J. Gen. Virol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"378","DOI":"10.1177\/1098612X17729626","article-title":"Efficacy of a 3C-like protease inhibitor in treating various forms of acquired feline infectious peritonitis","volume":"20","author":"Pedersen","year":"2018","journal-title":"J. Feline Med. Surg."},{"key":"ref_28","first-page":"214","article-title":"In vitro evaluation of the synergistic antiviral effects of acemannan in combination with azidothymidine and acyclovir","volume":"3","author":"Kahlon","year":"1991","journal-title":"Mol. Biother."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1092","DOI":"10.1128\/JVI.77.2.1092-1104.2003","article-title":"Antiviral effect and virus-host interactions in response to alpha interferon, gamma interferon, poly (i)-poly (c), tumor necrosis factor alpha, and ribavirin in hepatitis C virus subgenomic replicons","volume":"77","author":"Lanford","year":"2003","journal-title":"J. Virol."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"8091","DOI":"10.1073\/pnas.0711942105","article-title":"Delayed antiviral plus immunomodulator treatment still reduces mortality in mice infected by high inoculum of influenza A\/H5N1 virus","volume":"105","author":"Zheng","year":"2008","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Addie, D.D., Silveira, C., Aston, C., Brauckmann, P., Covell-Ritchie, J., Felstead, C., Fosbery, M., Gibbins, C., Macaulay, K., and McMurrough, J. (2022). Alpha-1 Acid Glycoprotein Reduction Differentiated Recovery from Remission in a Small Cohort of Cats Treated for Feline Infectious Peritonitis. Viruses, 14.","DOI":"10.21203\/rs.3.rs-1145695\/v1"}],"container-title":["Pathogens"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-0817\/11\/8\/881\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T00:04:00Z","timestamp":1760141040000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-0817\/11\/8\/881"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,8,4]]},"references-count":31,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2022,8]]}},"alternative-id":["pathogens11080881"],"URL":"https:\/\/doi.org\/10.3390\/pathogens11080881","relation":{},"ISSN":["2076-0817"],"issn-type":[{"value":"2076-0817","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,8,4]]}}}