Segarra S. et al. 2017
First-line treatment for canine leishmaniosis (CanL) is N-methylglucamine antimoniate (MGA) combined with allopurinol. However, in some dogs allopurinol may induce hyperxanthinuria leading to urolithiasis. Moreover, allopurinol resistance has recently been described in Leishmania infantum isolates from treated dogs with a relapse of the disease. Alternative treatments are thus needed.
Some authors have argued that the future of CanL management may be a combination of parasiticidal and parasitostatic treatments to eliminate the parasite and immuno-modulators so as to elicit an appropriate and more efficient immune response against the parasite. In effect, a recent study has shown that an immune system-modulating diet can improve the immune response in dogs with leishmaniosis under standard pharmacological treatment
Since the type of host immune response strongly influences CanL progression and prognosis, dogs could benefit from treatments targeted at modulating such response, such as nucleotides and active hexose correlated compound (AHCC) [a fungal extract of the Basidiomycetes family, composed of 74% of oligosaccharide chains E.N]. The aim of this study was to evaluate the effects of an oral combination of nucleotides and AHCC in dogs with clinical leishmaniosis.
This randomized, multicenter, open-label, positively-controlled clinical trial has been implemented on 69 dogs with clinical leishmaniasis divided into two groups: ALLOPURINOL GROUP (38 dogs) to received 10mg / kg of allopurinol PO, BID for 6 months and SUPPLEMENT GROUP (31 dogs) to which a diet was administered 17mg/kg AHCC PLUS 32mg / kg nucleotide supplement PO, SID for 180 days. All dogs were also given MGA (50mg / kg SC BID) during the first 28 days.
Clinical follow-up evaluations were conducted by each corresponding veterinarian on days 0 (day of enrollment), 30, and 180 of treatment. Each follow-up session consisted of a general physical exam and scoring for clinical signs associated with CanL using a scoring system adapted from Miró et al. Several analytes were measured from blood, urine, and bone marrow samples.
After 180 days of treatment were revealed a significant improvement in both groups in clinical scores and antibody titers after treatment. Parasite loads (RT-PCR) were reduced in groups, but there were no significant differences over time or between groups. During the study, 12 dogs in the allopurinol group developed xanthinuria compared to no dogs in the supplement group.
In conclusion, 6-month oral treatment with nucleotides and AHCC in addition to MGA showed similar efficacy to the current first-line treatment for CanL, without producing xanthinuria
This study provides a novel therapeutic alternative for the management of clinically healthy dogs with leishmaniosis based on immunomodulation of the disease through nutrition. As reported herein, suggesting the use of this supplement for preventive purposes.
Nevertheless, the present study has some limitations. First, it was an open-label study and, although the clinical changes were evaluated using a comprehensive scoring system, some of the parameters could not be assessed in a completely objective manner. Although all dogs received a regular diet, different trademarks and formulations were used among dogs from the study. Therefore, whether the diet affected the immune system of these dogs cannot be ruled out.
This results, together with the above-mentioned limitations, open the door for further investigations. Additional clinical trials with a larger sample sizes, a proper clinical staging of patients [1], longer follow-up, and also combining the supplement with other leishmanicidal drugs would be desirable in order to further confirm our observations.
Based on findings from this study and also on prior observations in sick CanL patients a combination of nucleotides and AHCC might become a useful tool either as sole therapy in clinically healthy infected dogs or as an adjunctive treatment to already existing therapies in sick dogs in order to obtain better clinical efficacy and perhaps be able to reduce dosages of anti-Leishmania drugs and thereby lower the risk of developing resistances and side effects.