Infektion mit dem felinen Leukämievirus – der Weg zur Diagnose

Zusammenfassung

Die Infektion mit dem felinen Leukämievirus (FeLV) kommt bei Katzen weltweit vor. Der Verlauf einer Infektion kann unterschiedlich sein und sich über die Zeit verändern. Die komplexe Pathogenese, die Verfügbarkeit vieler verschiedener Testverfahren und die Interpretation der Testergebnisse stellen Tierärzte oftmals vor eine Herausforderung. Katzen mit einer progressiven Infektion (persistierend p27-Antigen-positiv) scheiden FeLV vorwiegend über den Speichel aus und gelten daher als Ansteckungsquelle für andere nicht infizierte Katzen. Schwieriger zu erkennen sind Katzen mit einer regressiven Infektion, da sie mit herkömmlichen Schnelltests (p27-Antigentest) in der Regel nicht erfasst werden und unerkannt bleiben. Dennoch sind diese Katzen FeLV-Träger (Provirus-positiv) und bei Schwächung des Immunsystems kann es zu einer Reaktivierung der Infektion und FeLV-assoziierten klinischen Symptomen kommen. Abortiv infizierte Katzen sind zu keinem Zeitpunkt virämisch, scheiden kein Virus aus und entwickeln keine klinischen Symptome. Eine abortive Infektion kann nur durch den Nachweis von Antikörpern im Blut diagnostiziert werden. Ein neuer Schnelltest zum Nachweis von Antikörpern gegen FeLV-p15E-Antigen wurde kürzlich auf dem europäischen Markt eingeführt und wird gerade evaluiert.

Abstract

Feline leukemia virus (FeLV) infection affects cats worldwide. The course of FeLV infection can change and vary over time. The complex pathogenesis, the availability of many different testing methods, and the interpretation of test results are often challenging for veterinarians. Cats with progressive infection (persistently p27 antigen-positive) shed FeLV mainly through saliva and are therefore considered a source of infection for uninfected cats. Diagnosing regressive infection is often challenging, since it usually cannot be detected by commonly used point of care-tests (p27 antigen test) and thus, it often remains undetected. Nevertheless, cats with regressive infection are FeLV carriers (provirus-positive) and when the immune system is suppressed, reactivation of the infection and FeLV-associated clinical signs can occur. Abortively infected cats are never viraemic, do not shed virus, and do not develop clinical signs. Abortive infection can solely be diagnosed via antibodies detection in blood. A new point-of-care test for the identification of antibodies against FeLV p15E antigen has recently been introduced on the European market and is currently being evaluated.

Schlüsselwörter

FeLV - p27-Antigen - virale RNA - provirale DNA - anti-FeLV-Antikörper

Key words

FeLV - p27 antigen - viral RNA - proviral DNA - anti-FeLV antibodies

• Literatur

• 1 Hartmann K, Hofmann-Lehmann R. What’s new in feline leukemia virus infection. Vet Clin North Am Small Anim Pract 2020; 50: 1013-1036
• 2 Hofmann-Lehmann R, Hartmann K. Feline leukaemia virus infection: a practical approach to diagnosis. J Feline Med Surg 2020; 22: 831-846
• 3 Little S, Levy J, Hartmann K. et al. 2020 AAFP feline retrovirus testing and management guidelines. J Feline Med Surg 2020; 22: 5-30
• 4 Hofmann-Lehmann R, Holznagel E, Ossent P. et al. Parameters of disease progression in long-term experimental feline retrovirus (feline immunodeficiency virus and feline leukemia virus) infections: hematology, clinical chemistry, and lymphocyte subsets. Clin Diagn Lab Immun 1997; 4: 33-42
• 5 Helfer-Hungerbuehler AK, Widmer S, Kessler Y. et al. Long-term follow up of feline leukemia virus infection and characterization of viral RNA loads using molecular methods in tissues of cats with different infection outcomes. Virus Res 2015; 197: 137-150
• 6 Erbeck K, Gagne RB, Kraberger S. et al. Feline Leukemia Virus (FeLV) endogenous and exogenous recombination events result in multiple FeLV-B subtypes during natural infection. J Virol 2021; 95: e0035321
• 7 Chiu ES, Hoover EA, VandeWoude S. A retrospective examination of feline leukemia subgroup characterization: viral interference assays to deep sequencing. Viruses 2018; 10
• 8 Cheng HH, Anderson MM, Hankenson FC. et al. Envelope determinants for dual-receptor specificity in feline leukemia virus subgroup A and T variants. J Virol 2006; 80: 1619-1628
• 9 Gomes-Keller MA, Gonczi E, Tandon R. et al. Detection of feline leukemia virus RNA in saliva from naturally infected cats and correlation of PCR results with those of current diagnostic methods. J Clin Microbiol 2006; 44: 916-922
• 10 Gomes-Keller MA, Tandon R, Gonczi E. et al. Shedding of feline leukemia virus RNA in saliva is a consistent feature in viremic cats. Vet Microbiol 2006; 112: 11-21
• 11 Gomes-Keller MA, Gonczi E, Grenacher B. et al. Fecal shedding of infectious feline leukemia virus and its nucleic acids: a transmission potential. Vet Microbiol 2009; 134: 208-217
• 12 Major A, Cattori V, Boenzli E. et al. Exposure of cats to low doses of FeLV: seroconversion as the sole parameter of infection. Vet Res 2010; 41: 17
• 13 Pacitti A, Jarrett O, Hay D. Transmission of feline leukaemia virus in the milk of a non-viraemic cat. Vet Rec 1986; 118: 381-384
• 14 Hardy WD, Hess PW, MacEwen EG. et al. Biology of feline leukemia virus in the natural environment. Cancer Res 1976; 36: 582-588
• 15 Willett BJ, Hosie MJ. Feline leukaemia virus: half a century since its discovery. Vet J 2013; 195: 16-23
• 16 Lutz H. Feline Retroviren. In: Horzinek MC, Lutz H, Schmidt V. Hrsg. Krankheiten der Katze. 4. Aufl. Thieme; 2019: 359-373
• 17 Haraguchi S, Good RA, Day-Good NK. A potent immunosuppressive retroviral peptide: cytokine patterns and signaling pathways. Immunol Res 2008; 41: 46-55
• 18 Langhammer S, Fiebig U, Kurth R. et al. Neutralising antibodies against the transmembrane protein of feline leukaemia virus (FeLV). Vaccine 2005; 23: 3341-3348
• 19 Hofmann-Lehmann R, Cattori V, Tandon R. et al. Vaccination against the feline leukaemia virus: outcome and response categories and long-term follow-up. Vaccine 2007; 25: 5531-5539
• 20 Gleich SE, Krieger S, Hartmann K. Prevalence of feline immunodeficiency virus and feline leukaemia virus among client-owned cats and risk factors for infection in Germany. J Feline Med Surg 2009; 11: 985-992
• 21 Hoover E, Mullins JI. Feline leukemia virus infection and diseases. J Am Vet Med Assoc 1991; 199: 1287-1297
• 22 Flynn J, Hanlon L, Jarrett O. Feline leukaemia virus: protective immunity is mediated by virus-specific cytotoxic T lymphocytes. Immunology 2000; 101: 120-125
• 23 Rojko J, Kociba G. Pathogenesis of infection by the feline leukemia virus. J Am Vet Med Assoc 1991; 199: 1305-1310
• 24 Rojko JL, Hoover EA, Mathes LE. et al. Pathogenesis of experimental feline leukemia virus infection. J Natl Cancer I 1979; 63: 759-768
• 25 Hofmann-Lehmann R, Huder JB, Gruber S. et al. Feline leukaemia provirus load during the course of experimental infection and in naturally infected cats. J Gen Virol 2001; 82: 1589-1596
• 26 Beall MJ, Buch J, Clark G. et al. Feline leukemia virus p27 antigen concentration and proviral DNA load are associated with survival in naturally infected cats. Viruses 2021; 13
• 27 Hartmann K. Clinical aspects of feline retroviruses: a review. Viruses 2012; 4: 2684-2710
• 28 Lutz H, Pedersen N, Higgins J. et al. Humoral immune reactivity to feline leukemia virus and associated antigens in cats naturally infected with feline leukemia virus. Cancer Res 1980; 40: 3642-3651
• 29 Parr YA, Beall MJ, Levy JK. et al. Measuring the humoral immune response in cats exposed to feline leukaemia virus. Viruses 2021; 13
• 30 Hofmann-Lehmann R, Holznagel E, Aubert A. et al. Recombinant FeLV vaccine: long-term protection and effect on course and outcome of FIV infection. Vet Immunol Immunopathol 1995; 46: 127-137
• 31 Pepin AC, Tandon R, Cattori V. et al. Cellular segregation of feline leukemia provirus and viral RNA in leukocyte subsets of long-term experimentally infected cats. Virus Res 2007; 127: 9-16
• 32 Torres AN, Mathiason CK, Hoover EA. Re-examination of feline leukemia virus: host relationships using real-time PCR. Virology 2005; 332: 272-283
• 33 Boenzli E, Hadorn M, Hartnack S. et al. Detection of antibodies to the feline leukemia Virus (FeLV) transmembrane protein p15E: an alternative approach for serological FeLV detection based on antibodies to p15E. J Clin Microbiol 2014; 52: 2046-2052
• 34 Englert T, Lutz H, Sauter-Louis C. et al. Survey of the feline leukemia virus infection status of cats in Southern Germany. J Feline Med Surg 2012; 14: 392-398
• 35 Westman M, Norris J, Malik R. et al. The diagnosis of feline leukaemia virus (FeLV) infection in owned and group-housed rescue cats in Australia. Viruses 2019; 11
• 36 Hayes K, Rojko J, Mathes L. Incidence of localized feline leukemia virus infection in cats. Am J Vet Res 1992; 53: 604
• 37 Levy J, Crawford C, Hartmann K. et al. 2008 American Association of Feline Practitioners’ feline retrovirus management guidelines. J Feline Med Surg 2008; 10: 300-316
• 38 Studer N, Lutz H, Saegerman C. et al. Pan-European study on the prevalence of the feline leukaemia virus infection – reported by the European Advisory Board on Cat Diseases (ABCD Europe). Viruses 2019; 11: 993
• 39 Burling AN, Levy JK, Scott HM. et al. Seroprevalences of feline leukemia virus and feline immunodeficiency virus infection in cats in the United States and Canada and risk factors for seropositivity. J Am Vet Med Assoc 2017; 251: 187-194
• 40 Hofmann-Lehmann R, Gonczi E, Riond B. et al. Feline leukemia virus infection: importance and current situation in Switzerland. Schweiz Arch Tierheilkd 2018; 160: 95-105
• 41 Westman ME, Paul A, Malik R. et al. Seroprevalence of feline immunodeficiency virus and feline leukaemia virus in Australia: risk factors for infection and geographical influences (2011–2013). JFMS Open Rep 2016; 2: 2055116916646388
• 42 Gates M, Vigeant S, Dale A. Prevalence and risk factors for cats testing positive for feline immunodeficiency virus and feline leukaemia virus infection in cats entering an animal shelter in New Zealand. New Zeal Vet J 2017; 65: 285-291
• 43 Soe LH, Shimizu RW, Landolph JR. et al. Molecular analysis of several classes of endogenous feline leukemia virus elements. Journal of virology 1985; 56: 701-710
• 44 Muz D, Can H, Karakavuk M. et al. The molecular and serological investigation of Feline immunodeficiency virus and Feline leukemia virus in stray cats of Western Turkey. Comp Immunol Microbiol Infect Dis 2021; 78: 101688
• 45 Levy JK, Scott HM, Lachtara JL. et al. Seroprevalence of feline leukemia virus and feline immunodeficiency virus infection among cats in North America and risk factors for seropositivity. J Am Vet Med Assoc 2006; 228: 371-376
• 46 Cattori V, Tandon R, Riond B. et al. The kinetics of feline leukaemia virus shedding in experimentally infected cats are associated with infection outcome. Vet Microbiol 2009; 133: 292-296
• 47 Hofmann-Lehmann R, Tandon R, Boretti FS. et al. Reassessment of feline leukaemia virus (FeLV) vaccines with novel sensitive molecular assays. Vaccine 2006; 24: 1087-1094
• 48 Hartmann K, Werner R-M, Egberink H. et al. Comparison of six in-house tests for the rapid diagnosis of feline immunodeficiency and feline leukaemia virus infections. Vet Rec 2001; 149: 317-320
• 49 Hartmann K, Griessmayr P, Schulz B. et al. Quality of different in-clinic test systems for feline immunodeficiency virus and feline leukaemia virus infection. J Feline Med Surg 2007; 9: 439-445
• 50 Sand C, Englert T, Egberink H. et al. Evaluation of a new in-clinic test system to detect feline immunodeficiency virus and feline leukemia virus infection. Vet Clin Pathol 2010; 39: 210-214
• 51 Liu J, O’Connor T, Beall M. et al. Evaluation of rapid diagnostic test kits for feline leukemia virus infection using samples from naturally infected cats. JFMS Open Rep 2016; 2
• 52 Levy JK, Crawford PC, Tucker SJ. Performance of 4 point-of-care screening tests for feline leukemia virus and feline immunodeficiency virus. J Vet Intern Med 2017; 31: 521-526
• 53 Westman ME, Malik R, Hall E. et al. Comparison of three feline leukaemia virus (FeLV) point-of-care antigen test kits using blood and saliva. Comp Immunol Microbiol Infect Dis 2017; 50: 88-96
• 54 Sykes J, Hartmann K. Feline Leukemia Virus Infection. Canine and Feline Infectious Diseases 2013; 224-238
• 55 Hardy W, Hirshaut Y, Hess P. Detection of the Feline Leukemia Virus and other Mammalian Oncornaviruses by Immunofluorescence. Bibl Haematol 1973; 39: 778-799
• 56 Tandon R, Cattori V, Willi B. et al. Quantification of endogenous and exogenous feline leukemia virus sequences by real-time PCR assays. Vet Immunol Immunopathol 2008; 123: 129-133
• 57 Mehrotra S, Mishra KP, Yadav VS. et al. Immunomodulation by peptide analogs of retroviral envelope protein. Peptides 2003; 24: 979-985
• 58 Langhammer S, Hubner J, Kurth R. et al. Antibodies neutralizing feline leukaemia virus (FeLV) in cats immunized with the transmembrane envelope protein p15E. Immunology 2006; 117: 229-237
• 59 Helfer-Hungerbuehler AK, Spiri AM, Riond B. et al. No benefit of therapeutic vaccination in clinically healthy cats persistently infected with feline leukemia virus. Vaccine 2015; 33: 1578-1585
• 60 Hartmann K, Day MJ, Thiry E. et al. Feline injection-site sarcoma: ABCD guidelines on prevention and management. J Feline Med Surg 2015; 17: 606-613
• 61 Scherk MA, Ford RB, Gaskell RM. et al. 2013 AAFP Feline Vaccination Advisory Panel Report. J Feline Med Surg 2013; 15: 785-808
• 62 Hartmann K, Kohn B, Moritz A. et al. Leitlinie zur Impfung von Kleintieren, Ständige Impfkommision Veterinär (StiKo Vet). 2021: 15-18
• 63 Mostl K, Egberink H, Addie D. et al. Prevention of infectious diseases in cat shelters: ABCD guidelines. J Feline Med Surg 2013; 15: 546-554
• 64 Lutz H, Addie D, Belák S. et al. Feline leukaemia. ABCD guidelines on prevention and management. J Feline Med Surg 2009; 11: 565-574
• 65 Nesina S, Katrin Helfer-Hungerbuehler A, Riond B. et al. Retroviral DNA-the silent winner: blood transfusion containing latent feline leukemia provirus causes infection and disease in naive recipient cats. Retrovirology 2015; 12: 105