A 1.6-year-old male domestic short hair cat was brought to the Veterinary Medical Teaching Hospital, Kasetsart University, with signs of severe anemia, depression, and general lymph node enlargement. Complete blood count revealed leukocytosis and massive undifferentiated blasts. Testing for antibodies specific to feline leukemia virus (FeLV) was positive, and FeLV nucleic acid was confirmed by nested polymerase chain reaction. Base on cytochemistry and ultrastructure, the cat was diagnosed with acute monoblastic leukemia.
Animals ; Cat Diseases/*diagnosis/*virology ; Cats ; Leukemia Virus, Feline/*isolation & purification ; Leukemia, Monocytic, Acute/diagnosis/*veterinary/virology ; Male ; Osteoblasts/ultrastructure

Feline leukemia virus (FeLV) causes a range of neoplastic and degenerative diseases in cats. To obtain a more sensitive and convenient diagnosis of the disease, we prepared monoclonal antibodies specific for the FeLV p27 to develop a rapid diagnostic test with enhanced sensitivity and specificity. Among these antibodies, we identified two clones (hybridomas 8F8B5 and 8G7D1) that specifically bound to FeLV and were very suitable for a diagnostic kit. The affinity constants for 8F8B5 and 8G7D1 were 0.35 x 10(9) and 0.86 x 10(9), respectively. To investigate the diagnostic abilities of the rapid kit using these antibodies, we performed several clinical studies. Assessment of analytical sensitivity revealed that the detection threshold of the rapid diagnostic test was 2 ng/mL for recombinant p27 and 12.5 x 10(4) IU/mL for FeLV. When evaluating 252 cat sera samples, the kit was found to have a kappa value of 0.88 compared to polymerase chain reaction (PCR), indicating a significant correlation between data from the rapid diagnostic test and PCR. Sensitivity and specificity of the kit were 95.2% (20/21) and 98.5% (257/261), respectively. Our results demonstrated that the rapid diagnostic test would be a suitable diagnostic tool for the rapid detection of FeLV infection in cats.
Animals ; Antibodies, Monoclonal/blood ; Cats ; Diagnostic Tests, Routine/*veterinary ; Female ; Gene Products, gag/*blood ; Leukemia Virus, Feline/immunology/*isolation & purification ; Leukemia, Feline/*diagnosis ; Mice, Inbred BALB C ; Sensitivity and Specificity