Treatment with Class A CpG Oligodeoxynucleotides in Cats with Naturally Occurring Feline Parvovirus Infection: A Prospective Study.

Filippo Ferri,Carolina Callegari,Federico Porporato,Regina Hofmann-Lehmann,Chiara Crinò,Barbara Contiero,Luigi M Coppola,Neda Ranjbar Kohan,Eric Zini,Gabriele Gerardi,Daniela Enache,Hans Lutz,Marina L Meli,Francesco Rossi

doi:10.3390/v12060640

Abstract

Feline parvovirus (FPV) causes severe gastroenteritis and leukopenia in cats; the outcome is poor. Information regarding specific treatments is lacking. Class A CpG oligodeoxynucleotides (CpG-A) are short single-stranded DNAs, stimulating type I interferon production. In cats, CpG-A induced an antiviral response in vivo and inhibited FPV replication in vitro. The aim was to prospectively investigate the effects of CpG-A on survival, clinical score, hematological findings, antiviral response (cytokines), viremia, and fecal shedding (real-time qPCR) in cats naturally infected with FPV. Forty-two FPV-infected cats were randomized to receive 100 µg/kg of CpG-A (n = 22) or placebo (n = 20) subcutaneously, on admission and after 48 h. Blood and fecal samples were collected on admission, after 1, 3, and 7 days. All 22 cats showed short duration pain during CpG-A injections. The survival rate, clinical score, leukocyte and erythrocyte counts, viremia, and fecal shedding at any time-point did not differ between cats treated with CpG-A (50%) and placebo (40%). Antiviral myxovirus resistance (Mx) gene transcription increased in both groups from day 1 to 3 (p = 0.005). Antibodies against FPV on admission were associated with survival in cats (p = 0.002). In conclusion, CpG-A treatment did not improve the outcome in cats with FPV infection. FPV infection produced an antiviral response.

Highlights

Feline parvovirus (FPV) is a small, non-enveloped, serologically homogeneous parvovirus with a single-stranded DNA genome
The aim of this study was to investigate the effects of CpG ODN 2216 administration on survival, clinical signs, laboratory findings, antiviral response, viremia, and viral shedding in cats naturally infected with FPV
Assuming similar outcome rates (i.e., 50% and 40%), in order to achieve a significant difference between CpG ODN 2216 and placebo groups with a power of 0.80, approximately 400 cats would have been needed in each group

Summary

Introduction

Feline parvovirus (FPV) is a small, non-enveloped, serologically homogeneous parvovirus with a single-stranded DNA genome. Cats affected by feline panleukopenia present severe hemorrhagic. The infection is highly contagious and associated with high morbidity and mortality rates, with the latter ranging from 25 to 90% and up to 100% in cats with acute and hyper-acute infections, respectively. The severity of clinical signs, thrombocytopenia, hypoalbuminemia, hypokalemia, glucose administration, total T4 have been identified as negative prognostic factors in cats infected by FPV, whereas leukopenia has been inconstantly recognized as a negative outcome predictor [3,4,5]. No specific antiviral therapy against FPV infection has been tested in cats, and its management relies upon supportive treatment. Plasma or whole blood transfusion may be required in case of severe hypoproteinemia or anemia, respectively [3,4,5,6]. Feline interferon regulatory factor-1 has been found to reduce the replication of FPV on Crandell-Rees feline kidney cells [7], but no information is yet available in vivo

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