Feline Immunodeficiency Virus Positive Cats Research Articles

Impacts of Antiretroviral Therapy on the Oral Microbiome and Periodontal Health of Feline Immunodeficiency Virus Positive Cats.

Feline immunodeficiency virus (FIV) is the domestic cat analogue of HIV infection in humans. Both viruses induce oral disease in untreated individuals, with clinical signs that include gingivitis and periodontal lesions. Oral disease manifestations in HIV patients are abated by highly effective combination antiretroviral therapy (cART), though certain oral manifestations persist despite therapy. Microorganisms associated with oral cavity opportunistic infections in patients with HIV cause similar pathologies in cats. To further develop this model, we evaluated characteristics of feline oral health and oral microbiome during experimental FIV infection over an 8-month period following cART. Using 16S metagenomics sequencing, we evaluated gingival bacterial communities at four timepoints in uninfected and FIV-infected cats treated with cART or placebo. Comprehensive oral examinations were also conducted by a veterinary dental specialist over the experimental period. Gingival inflammation was higher in FIV-infected cats treated with placebo compared to cART-treated cats and controls at study endpoint. Oral microbiome alpha diversity increased in all groups, while beta diversity differed among treatment groups, documenting a significant effect of cART therapy on microbiome community composition. This finding has not previously been reported and indicates cART ameliorates immunodeficiency virus-associated oral disease via preservation of oral mucosal microbiota. Further, this study illustrates the value of the FIV animal model for investigations of mechanistic associations and therapeutic interventions for HIV oral manifestations.

The efficacy of recombinant feline interferon-omega in treating symptomatic cats infected with feline immunodeficiency virus

PICO Question In symptomatic cats with feline immunodeficiency virus (FIV), does high-dose subcutaneous recombinant feline interferon-omega (rFeIFN-ω) administration lead to reduced clinical signs compared to cats who were not administered rFeIFN-ω? Clinical bottom line Category of research Treatment. Number and type of study designs reviewed Three studies were critically reviewed, including one randomised controlled trial, one non-randomised controlled trial, and one uncontrolled clinical trial. Strength of evidence Weak. Outcomes reported Each of the studies reported that rFeIFN-ω administration significantly reduced clinical signs in FIV infected cats. However, all three papers have limitations in their study design and statistical analysis which lower the strength of the evidence they provide. Conclusion There is only weak evidence demonstrating that rFeIFN-ω administration leads to reduced clinical signs in FIV positive cats. Currently, there is a lack of well-designed, double-blinded, randomised, placebo-controlled clinical trials which have an adequate sample size and specifically focus on FIV positive cats. As a result, more robust evidence is needed to prove the definitive therapeutic benefit of rFeIFN-ω in symptomatic FIV patients. Treatment with rFeIFN-ω may still be considered by clinicians for cats with clinical signs potentially associated with retroviral infection, such as oral lesions and stomatitis, particularly if they are not responding well to supportive therapy alone. How to apply this evidence in practice The application of evidence into practice should take into account multiple factors, not limited to: individual clinical expertise, patient’s circumstances and owners’ values, country, location or clinic where you work, the individual case in front of you, the availability of therapies and resources. Knowledge Summaries are a resource to help reinforce or inform decision making. They do not override the responsibility or judgement of the practitioner to do what is best for the animal in their care.

Animal shelter management of feline leukemia virus and feline immunodeficiency virus infections in cats.

Approximately 5% of cats in animal shelters in the United States test positive for either feline leukemia virus (FeLV) or feline immunodeficiency virus (FIV), which translates to more than 100,000 positive cats managed by shelters each year. Little is known about the current status of retroviral management in animal shelters, particularly in regions burdened by chronic pet overpopulation and high shelter admissions, such as the southern United States. The purpose of this study was to describe feline retroviral management in Florida shelters. Shelters were surveyed on practices including selection of cats for testing, diagnostic techniques, and outcome options for cats with positive test results. Responses were received from 139 of 153 animal shelters known to admit cats, including 55 municipal shelters (40%), 70 private shelters (50%), and 14 private shelters with municipal contracts (10%). A total of 115 shelters (83%) performed at least some testing, most using combination point-of-care devices for simultaneous FeLV antigen and FIV antibody screening. Of shelters that performed any testing, 56 (49%) tested all cats for FeLV and 52 (45%) tested all cats for both FeLV and FIV. The most common reason for testing was screening adoptable cats (108 shelters; 94%) and cats available for transfer to other organizations (78; 68%). Testing cats in trap-neuter-return/return-to-field programs was least common (21; 18%). Most common outcome options for positive cats included adoption (74; 64%), transfer (62; 54%), and euthanasia (49; 43%). Euthanasia following a positive test result was more common for cats with FeLV (49; 43%) than for cats with FIV (29; 25%) and was more common in municipal shelters, rural shelters, shelters taking in <500 cats a year, and shelters with overall live outcome rates for cats <70%. Although Florida shelter compliance with national guidelines for identification and management of FeLV and FIV positive cats was variable, most had live outcome options for at least some of their cats with positive test results. Increased access to training and practical programmatic tools may help more shelters implement cost-effective testing protocols, reduce risk for transmission to other cats, and support the best outcomes for this vulnerable population of cats.

High rate of feline immunodeficiency virus infection in cats in the Brazilian semiarid region: Occurrence, associated factors and coinfection with Toxoplasma gondii and feline leukemia virus

To evaluate the occurrence of feline immunodeficiency virus (FIV) and factors associated with this and to demonstrate occurrences of coinfection with Toxoplasma gondii and feline leukemia virus (FeLV) in cats, a total of 103 blood samples were collected from owned cats, during home visits. To diagnose FIV and FeLV, immunochromatographic kit was used and serological diagnoses of T. gondii, the indirect immunofluorescence test was performed. The occurrence of FIV-seropositive cats was 23.3% (24/103) and the factor associated with infection was male sex. T. gondii seropositivity of 53.4% (55/103) was observed and 75% of FIV cases (18/24) were positive for T. gondii coinfection. Only 0.9% (1/103) was positive for FeLV. It can be concluded that the seroprevalence of FIV in cats in the Brazilian semiarid region is high and that FIV positive cats were also likely to be T. gondii seropositive, while FeLV had very low occurrence in the study region.

Monocyte-Derived Dendritic Cells from Feline Immunodeficiency Virus Positive Cats are Productively Infected and Maintain CD8+ T Cell Stimulatory Capacity

Dendritic cells (DCs) have been utilized to enhance CD8+ T cell responses to pathogen-associated peptides for enhancement of vaccine efficacy. CD8+ T cells play a central role in the elimination of viruses during acute viral infection and control of viremia during chronic viral infection. For lentiviral infections such as HIV and FIV, dendritic cell vaccines may be useful for augmenting CD8+ T cell function. Therefore, we asked if monocyte-derived dendritic cells (moDCs) from FIV+ chronically infected cats maintained the ability to stimulate CD8+ T cells in the absence of exogenous antigen, when compared to uninfected controls. Using high speed cell sorting, monocytes were isolated from PBMCs based on forward versus side scatter gating. Cells were then cultured with IL-4 and GM-CSF over the course of 6 days, and LPS was added to stimulate maturation after the first 72 hours. We confirmed the identity and maturation status of cells by cytologic examination and FITC-dextran uptake. We then assessed differences in CD8+ T cell proliferation in the presence of monocytes / macrophages (M/M), immature dendritic cells (iDCs), and mature dendritic cells (mDCs). We demonstrated that CD8+ T cell proliferation is maintained in the presence of DCs from FIV+ cats and that production of inflammatory cytokines and chemokines by DCs from FIV+ cats is retained in vitro. Further, we confirmed the presence of virus in co-culture. These results suggest that moDCs from FIV-infected animals serve as viral reservoirs. More importantly, these results support our hypothesis that moDCs maintain the ability to stimulate CD8+ T cells during chronic lentiviral infection.

Oral Recombinant Feline Interferon-Omega as an alternative immune modulation therapy in FIV positive cats: Clinical and laboratory evaluation

Recombinant-Feline Interferon-Omega (rFeIFN-ω) is an immune-modulator licensed for use subcutaneously in Feline Immunodeficiency virus (FIV) therapy. Despite oral protocols have been suggested, little is known about such use in FIV-infected cats. This study aimed to evaluate the clinical improvement, laboratory findings, concurrent viral excretion and acute phase proteins (APPs) in naturally FIV-infected cats under oral rFeIFN-ω therapy (0.1MU/cat rFeIFN-ω PO, SID, 90days). 11 FIV-positive cats were treated with oral rFeIFN-ω (PO Group). Results were compared to previous data from 7 FIV-positive cats treated with the subcutaneous licensed protocol (SC Group). Initial clinical scores were similar in both groups. Independently of the protocol, rFeIFN-ω induced a significant clinical improvement of treated cats. Concurrent viral excretion and APP’s variation were not significant in the PO Group. Oral rFeIFN-ω can be an effective alternative therapy for FIV-infected cats, being also an option for treatment follow-up in cats submitted to the licensed protocol.

Molecular subtyping of feline immunodeficiency virus from cats in Melbourne

To determine the subtypes of feline immunodeficiency virus (FIV) present in the domestic cat population in Melbourne. Blood samples were collected from 42 cats that had serum antibodies against FIV. DNA was extracted and subjected to polymerase chain reaction (PCR) to amplify variable regions of the envelope (env) and group specific antigen (gag) genes of FIV. PCR products were directly sequenced or sequenced after cloning when direct sequencing yielded ambiguous results. Phylogenetic analysis was performed and comparisons made with representative sequences of different subtypes. The variable region of the env gene was successfully amplified by PCR from 41 of the 42 cats. All 41 were found to cluster with subtype A env sequences. The variable region of the gag gene was successfully amplified by PCR from all 42 cats. Forty-one were found to cluster with subtype A gag genes and one was found to cluster with subtype B sequences, suggesting that it may be derived from a recombinant env A/gag B virus. Subtype A is the predominant FIV type in Melbourne, although a subtype A/B recombinant was identified in the population of FIV positive cats. These results of env gene analysis were similar to those in a previous Australian study, suggesting that subtype A predominates in Australia. The results of the gag gene analysis show the importance of analysing multiple areas of the FIV genome when assigning FIV subtypes. Comparison with other major urban centres may provide useful information about the phylogenic diversity of FIV in Australia.

High prevalence of Feline Immunodeficiency Virus (FIV) and Feline Leukemia Virus (FeLV) in Slovenia

The purpose of this study was to determine the prevalences of FIV and FeLV infections in domestic cats by the enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR). Of the 42 cats examined by the ELISA test, 14 (33.3 %) were seropositive for FIV antibody, 10 (23.8 %) for FeLV antigen, 1 (2.4 %) was positive for both viruses and 17 were negative for infection with either virus. In the PCR assay, 17 cats (40.5 %) were positive for FeLV, 11 (26.2%) for FIV, 9 (21.4%) for both viruses and 5 cats (11.9%) were negative for the presence of viral DNA. The average age of FIV positive cats was 6 and of FeLV 7 years. Infections were more common in outdoor cats (65% FIV, 61.1% FeLV positive) and in male cats (71.4% FIV, 80% FeLV). The results of both tests used in this study have shown high prevalence of both infections among cats in Slovenia. The ELISA method was found useful as a screening test for fast detection of FIV and FeLV infections, but additional testing with PCR was shown to be more effective in the characterization and progression of both infections.

Phylogenetic analysis to define feline immunodeficiency virus subtypes in 31 domestic cats in South Africa

Feline immunodeficiency virus (FIV), a lentivirus, is an important pathogen of domestic cats around the world and has many similarities to human immunodeficiency virus (HIV). A characteristic of these lentiviruses is their extensive genetic diversity, which has been an obstacle in the development of successful vaccines. Of the FIV genes, the envelope gene is the most variable and sequence differences in a portion of this gene have been used to define 5 FIV subtypes (A, B, C, D and E). In this study, the proviral DNA sequence of the V3-V5 region of the envelope gene was determined in blood samples from 31 FIV positive cats from 4 different regions of South Africa. Phylogenetic analysis demonstrated the presence of both subtypes A and C, with subtype A predominating. These findings contribute to the understanding of the genetic diversity of FIV.

Ocorrência de anticorpos antitoxoplasma em gatos infectados naturalmente pelo vírus da imunodeficiência dos felinos

In order to evaluate the occurrence of Toxoplasma gondii infection in cats infected with feline immunodeficiency virus (FIV), 22 serum samples obtained from diseased cats harbouring FIV were submitted to an indirect immunofluorescence antibody test to Toxoplasma. Another 58 ill cats, but that were negative for FIV antibody test and 35 healthy animals, also FIV negative, comprised the second and the third group, respectively. All cats were negative for feline leukemia virus test. The results showed that cats infected with FIV (Grupo I) presented a higher frequency of Toxoplasma antibody titer when compared to groups II and III. Also, a strong correlation was detected between FIV infection and positive serum reaction for Toxoplasma gondii. On the other hand, there was no difference in the magnitude of Toxoplasma antibody titer between positive and negative cats. Although cats that are seropositive to Toxoplasma rarely excrete oocysts in their feces, it is not well known how this immunity can influence oocysts shedding in cats infected with FIV. In consequence of the high frequency of antibody titer to Toxoplasma in FIV positive cats, these animals should always be submitted to antibody test to Toxoplasma.

Estudo clínico da síndrome de imunodeficiência adquirida em gatos domésticos de São Paulo

Com a finalidade de estudar a magnitude da ocorrência do vírus da leucemia felina (VLF) e do vírus da imunodeficiência dos felinos (VIF) entre os felinos domésticos de São Paulo, 401 animais de ambos os sexos, idade e raças variadas, foram submetidos à pesquisa de anticorpos humorais (VIF) e de antígenos virais solúveis (VLF) através do teste imunoenzimático - ELISA (Feline Leukímia Virus Antígen / Feline Immunodeficiency Virus Antibory - CITE® - Agritech Systems Inc.). Desses, 123 eram felinos sadios e os demais 278 animais eram felinos doentes atendidos no Departamento de Clínica Médica/Hospital Veterinário da FMVZ/USP. Foram observados 8 (6,5%) reagentes ao VIF entre os felinos sadios e 39 (14%) entre os gatos doentes. Em relação ao VLF, 2 (1,6%) dos animais sadios e 30 (10,8%) entre os gatos doentes foram reagentes ao teste imunoenzimático e apenas um animal foi reagente a ambos os vírus. A infecção pelo VIF foi mais freqüente entre os machos, quando comparada às fêmeas, na proporção de 4:1, não tendo sido, no entretanto, observada diferença entre machos e fêmeas infectados em relação ao VLF. As infecções oportunistas, como a causada por Haemobartonella felis, foram as doenças associadas mais freqüentemente observadas tanto nos felinos VLF positivos quanto nos VIF positivos. Em relação aos tumores, a forma mediastinal do linfoma foi a mais freqüente entre os felinos VLF positivos. As demais condições mórbidas que se associaram à infecção pelos dois Retrovirus foram de natureza e freqüência variáveis. A idade média dos animais infectados pelo VIF foi de 4,4 + 3,0 anos e dos felinos infectados pelo VLF, de 2,4 + 1,7 anos. Todos os animais reagentes e sintomáticos não sobreviveram mais do que dois anos. Por outro lado, não houve nenhum óbito entre os animais assintomáticos infectados por qualquer um dos Retrovirus durante o mesmo período de observação, demonstrando que operíodo de pré-patência pós-infecção pode ser bastante longo.

ネコ免疫不全ウイルス感染猫に認められた全身性アミロイドーシス

Two feline immunodeficiency virus-positive cats with renal insufficiency showed systemic amyloidosis, and amyloid deposit reacted with anti-amyloid A mouse monoclonal antibody.

Effects of Preactivated MC540 in the Treatment of Lymphocytic Plasmacytic Stomatitis in Feline Leukemia virus and Feline Immunodeficiency virus Positive Cats

Photoactive compounds and drugs are used therapeutically as antibacterial, antiviral and antitumor agents. This report examines the use of a photoactive compound, preactivated merocyanine 540 (pMC540), in the treatment of stomatitis in two cats that are both feline immunodeficiency virus (FIV) positive. One of the cats was also feline leukemia virus (FeLV) positive. Dramatic short term improvement is reported with the dosage regimen and complications.

Immunization-induced decrease of the CD4+:CD8+ ratio in cats experimentally infected with feline immunodeficiency virus

In a previous experiment a group of 15 specified pathogen free (SPF) cats were experimentally infected with a Swiss isolate of feline immunodeficiency virus (FIV). A group of 15 SPF cats served as FIV negative controls. Nine cats of each group were vaccinated with a recombinant feline leukemia virus (FeLV) vaccine, six cats in each group with a placebo vaccine. All vaccinated cats developed high antibody titers to FeLV and were protected against subsequent FeLV challenge infection. In both control groups five of six cats became persistently infected with FeLV. Unexpectedly, the primary immune response to the vaccine antigen was significantly higher in the FIV positive group than in the FIV negative. The secondary response was stronger in the FIV negative cats. The goal of the present investigation was to further study the immune response in these 30 cats. They were immunized twice with the synthetic peptide l-tyrosine- l-glutamic acid-poly( dl-alanine)-poly( l-lysine) (TGAL) 21 days apart. Blood samples were collected on four occasions during the immunization process. They were tested for antibodies to TGAL, complete blood cell counts and CD4+, CD8+ and pan- T-lymphocyte counts. The following observations were made: (1) in contrast to the FeLV vaccine experiment, the primary immune response to TGAL was not significantly stronger in the FIV positive cats when tested by enzyme-linked immunosorbent assay (2). The absolute size of the CD4+ lymphocyte population was distinctly smaller in the FIV positive than in the FIV negative cats. The lowest CD4+ values were found in the dually FIV/FeLV infected cats. (3) A population of CD8+ lymphocytes was identified that was characterized by a distinctly weaker fluorescence. The size of this population increased in FIV positive and decreased in FIV negative cats during the TGAL immunization experiment. (4) The CD4+:CD8+ ratio increased in FIV negative cats during TGAL immunization from 1.9 to 2.3. In contrast, in FIV positive animals the CD4+:CD8+ ratio decreased significantly from 1.9 to 1.3 during the same period. From these and earlier data it was concluded that in short-term FIV infection the immune response to T-cell dependent antigens may be increased over that of the controls. Immune suppression develops gradually with duration of the infection. The significant drop of the CD4+:CD8+ ratio over a 5 week immunization period suggests that antigenic stimulation may accelerate the development of immune suppression in FIV positive cats. If this is a general feature, FIV infection may provide a particularly interesting model for studying the pathogenesis of AIDS.