Felis Catus Gammaherpesvirus 1 DNAemia in Whole Blood from Therapeutically Immunosuppressed or Retrovirus-Infected Cats

Abstract

Gammaherpesviruses are major co-pathogens of human immunodeficiency virus (HIV) infection, making the interactions between feline immunodeficiency virus (FIV) and Felis catus gammaherpesvirus 1 (FcaGHV1) pertinent to both human and veterinary medical research. FIV-infected cats are at increased risk of FcaGHV1 DNAemia and consistently harbor higher FcaGHV1 loads than FIV-uninfected cats. Whether immune deficiencies unrelated to FIV are associated with similar risks is unknown. Using whole blood FcaGHV1 qPCR, we found no difference in the frequency of DNAemia or DNA load in therapeutically immunosuppressed (P1, n = 18) or feline leukemia virus (FeLV)-infected (P2, n = 57) patients compared with age- and sex-matched controls (C1, n = 58; C2, n = 57). In contrast, FIV/FeLV-co-infected cats (P3, n = 5) were at increased risk of FcaGHV1 DNAemia compared to retrovirus uninfected controls (C3, n = 39; p = 0.0068), and had a higher median FcaGHV1 DNA load, although the latter was not significant. FIV/FeLV-co-infected cats (P3) had a similar frequency of FcaGHV1 DNAemia reported compared to FIV-infected controls (C4). In conclusion, we found no evidence that cats with therapeutic immunosuppression or FeLV infection were at greater risk of FcaGHV1 DNAemia or had higher FcaGHV1 DNA load in whole blood. The risk of DNAemia in FIV/FeLV-co-infected cats was similar to that documented previously in cats infected with FIV alone.

Identification of Felis catus Gammaherpesvirus 1 in Tsushima Leopard Cats (Prionailurus bengalensis euptilurus) on Tsushima Island, Japan

“…Our observation that FeLV infection was not associated with an increased likelihood of FcaGHV1 DNA detection is congruent with previous reports [ 14 , 16 , 17 , 19 ] but contrasts with specific findings from Singapore where FeLV infection was significantly associated with FcaGHV1 detection [ 14 ]. On Tsushima Island, the prevalence rates of FeLV infection in Kamijima and Shimojima were 3.1% and 16.2%, respectively [ 6 ].…”

“…On Tsushima Island, the prevalence rates of FeLV infection in Kamijima and Shimojima were 3.1% and 16.2%, respectively [ 6 ]. However, data from epidemiological survey of feline viruses in Singapore, and of particular interest FeLV, were inconsistent [ 19 ]. Furthermore, it has been established that FeLV is primarily transmitted through non-aggressive interactions or vertical transmission, in contrast to the tendency of FcaGHV1 to be transmitted through fighting or territorial aggression [ 14 , 15 , 19 , 21 , 25 ].…”

“…The expansion of human habitats facilitates the spill-over of feline pathogens from domestic cats into wildlife populations; thus, determination of the pathogenic potential of FcaGHV1 is a priority for feline, human and wildlife health [ 14 ]. Previous studies have identified several risk factors for FcaGHV1 infection including adult and male status, geographical location, health status (sick) and co-pathogens [ 14 , 15 , 16 , 17 , 19 , 20 , 21 ].…”

Molecular Diagnosis of Felis catus Gammaherpesvirus 1 (FcaGHV1) Infection in Cats of Known Retrovirus Status with and without Lymphoma

“…Similar findings have been reported for EBV where DNAemia was associated with reduced survival in patients with diffuse large B-cell lymphoma, regardless of whether EBV DNA was detected in the tumour [ 47 ]. FIV infection is a strong risk factor for FcaGHV1 DNAemia, so the frequent documentation of dual infections, including six of 10 lymphoma cases in the survival analysis, was expected [ 7 , 8 , 25 ]. Co-infections were more common in the FcaGHV1-infected lymphoma cases than in the FcaGHV1 negative cases, which could contribute to poorer outcomes through an unknown mechanism.…”

“…Control samples were: (a) paired autologous uninvolved FFPE tissue from cases diagnosed on histopathology ( n = 33); (b) FFPE lymph node from cases with a diagnosis other than lymphoma ( n = 31); and (c) whole blood samples from cases from the same region with a diagnosis other than lymphoma, some of which have been reported previously ( n = 86; [ 25 ]). Data on age, sex and breed were recorded for all cases and controls, and retrovirus status was recorded, where available.…”