Clinical evaluation of antiviral combination treatment in cats with feline herpesvirus-1 infection.

Feline herpesvirus-1 (FHV-1) can cause lifelong problems such as rhinotracheitis and ocular disease due to latency and reactivation in affected cats. The particular effects of antiviral drugs have been separately investigated in previous studies for decades and little is known about the combination treatment in active FHV-1 infection. Therefore, we aimed to evaluate the effects of antiviral combination on clinical effectiveness in cats with naturally occurring FHV-1 infection. 28 cats suffering from clinical signs of sneezing, nasal congestion, conjunctivitis, and eye/nose discharge were involved in this study following FHV-1 DNA detection by PCR assay in oculo-oropharyngeal samples. The treatment protocol was as follows: oral famciclovir and L-lysine, ophthalmic acyclovir, and subcutaneous amoxicillin plus clavulanic acid. The symptoms improved each day and total recovery success rate was 80% reduction in clinical scores at the end of the treatment on day 10 (p<0.001). Additionally, PCR was found to be negative for FHV-1 DNA in 82.1% of the samples after the treatment. There were mild decreases in neutrophil and monocyte counts (p>0.05). The arginine to lysine ratio decreased in favour of lysine (p<0.01). As a result, the antiviral combination treatment with famciclovir, L-lysine and ophthalmic acyclovir, and antibacterial drug appears to be clinically effective for the treatment of naturally occurring active FHV-1 infection in cats. In addition, any adverse clinical effect has not been determined associated with the antiviral combination during the study.

Famciclovir leads to failure of hematopoiesis, but may have the benefit of relieving myeloid expansion in MDS-like zebrafish.

Famciclovir (FCV) is an antiviral drug that is often utilized after bone marrow transplantation to prevent viral infection. Yet, its role in hematopoiesis is poorly understood. Here, by utilizing a zebrafish model, we found that FCV exposure led to hematopoietic failure by impairing the proliferation of hematopoietic stem and progenitor cell (HSPC) and inducing HSPC apoptosis. On the other hand, FCV treatment could effectively relieve myeloid malignancies in the c-mybhyper MDS-like fish model, and played a role not only in the embryonic stage but also in adult zebrafish. This study reveals that FCV functions as a double-edged sword, with hematotoxicity at a high level, but that appropriate FCV treatment may be beneficial for the treatment of MDS.