DIAGNOSTIC TOOLS IN CANINE DIABETES MELLITUS AND CHRONIC
ENTEROPATHY
Paolo E. Crisi (1), Paraskevi Prasinou (1), Federico Fracassi (2), Fabio Procoli (3), Alessandro Gramenzi (1), Chryssostomos Chatgilialoglu (4), Carla Ferreri (4), Andrea Boari (1)
(1) Università degli Studi di Teramo, Facoltà di Medicina Veterinaria. (2) Università degli Studi di Bologna, Dipartimento di Scienze Mediche Veterinarie. (3) Ospedale Veterinario I Portoni Rossi, Zola Pedrosa,
Bologna. (4) ISOF, Consiglio Nazionale delle Ricerche, Bologna.
Analysis of red blood cells (RBC) membrane lipidome represents a powerful diagnostic tool in humans for assessing the quantity and quality of fatty acids and for the follow-up of the membrane remodeling under physiological and pathological conditions [1], however a systematic study to evaluate membrane homeostasis in dogs has not yet been established. The aim of this study was to compare RBC membrane lipidome profiles of healthy dogs (HD, n=17) with dogs newly diagnosed with diabetes mellitus (DM, n=6) and dogs with chronic signs (i.e. >3 weeks) of enteropathy (CE, n=6). All dogs receiving dietary ω3 supplementation were excluded from the study. The RBC membranes were isolated from EDTA-treated blood and a cluster made of 10 saturated [SFA (palmitic; stearic)], monounsaturated [MUFA (palmitoleic; oleic; vaccenic)] and polyunsaturated [PUFA (linoleic; dihomo-gamma-linolenic; arachidonic; EPA; DHA)] fatty acids was determined by Gas-Chromatography. The HD were 5 males (1 neutered) and 12 females (3 sterilized), with a median age of 38 months (2-98); DM dogs were 2 males and 4 females (2 sterilized), with a median age of 120 months (96-158), and all CE dogs were male (2 neutered) with a median age of 81 months (12-126). In HD SFA, MUFA and ω6 levels were close to each other, while the ω3 values showed a wider variability (mean 1.67%; SD 0.91%). The RBC fatty acid-based membrane lipidome profiles in DM and CE dogs compared to HD showed different trends connected to metabolic transformations along the fatty acid pathways. The CE dogs had decreased levels of palmitic acid (p<0.01) and higher stearic acid (p<0.01) whereas DM did not show significant changes in these values, compared to HD. The MUFA levels were interestingly diverse in the two health conditions: higher in DM (p<0.01) and lower in CE (p<0.05) compared to HD. In particular, CE dogs had lower levels of palmitoleic (p<0.05) and vaccenic acids (p<0.01), while DM dogs showed an increased content of palmitoleic (p<0.01) and oleic acids (p<0.01). As regards of ω6-PUFA, only in DM arachidonic acid levels differed if compared to the HD, in particular lower levels were observed (p<0.01). ω3-PUFA levels were increased only in DM dogs in comparison to HD, both for EPA (p<0.05) and DHA (p<0.05) values. These preliminary data have clear limitations as for the sample size, the lack of data in geriatric healthy dogs and the lack of retrospective diagnosis of disorders associated with the chronic enteropathy. The variability of ω3 values found in erythrocyte membranes of healthy dogs, can be probably due to the individual dietary variations. However, it can be preliminarily observed that the SFA-MUFA pathway shows significant involvement in canine diabetes mellitus, with a higher palmitic-palmitoleic and palmitic- oleic transformations due to an accelerated delta-9 desaturase enzymatic activity. On the other hand, CE dogs showed increased levels of stearic, and decreased palmitoleic and vaccenic acids suggesting an activation of elongation pathway, leading to profound changes of membrane fluidity and permeability properties. In conclusion, erythrocyte membrane lipidome of dogs may be successfully applied in veterinary medicine, providing important information of different profiles under normal and pathological conditions.
[1] Ferreri C. Chatgilialoglu C. Role of fatty acid-based functional lipidomics in the development of molecular diagnostic tools. Expert Rev Mol Diagn, 12(7):767–780, 2012.
SEVERE PARANEOPLASTIC HYPERCALCEMIA SECONDARY TO AN ORAL MELANOMA AND PALLIATIVE TREATMENT WITH ZOLEDRONIC ACID IN A DOG
Paolo E. Crisi (1), Morena Di Tommaso (1), Massimo Vignoli (1), Claudio D'Antonio (2), Salvatore Parrillo (1), Andrea Boari (1)
(1) Università degli Studi di Teramo, Facoltà di Medicina Veterinaria. (2) Ambulatorio Veterinario Associato D'antonio e Di Girolamo, Alba Adriatica, Teramo.
Paraneoplastic syndromes (PNSs) are neoplasm-associated disorders arising from tumor secretion of hormones, peptides, or cytokines or from immune cross-reactivity between malignant and normal tissues. Sometimes, PNSs are the first evidence of a neoplastic disease they cause more significant morbidity than the tumour itself. The most common cause of hypercalcaemia in dogs is an underlying malignancy, and neoplasia is diagnosed in approximatively two-thirds of dogs with hypercalcemia [1]. Melanoma-associated PNSs are anecdotally in dogs and hypercalcemia occurs in 1-2% of humans with malignant melanoma, usually due to osteolysis and resulting release calcium into the bloodstream [2,3]. A 10-year-old male Boxer was referred to the Veterinary Teaching Hospital (VTH) of Teramo after a 3-days history of weakness, anorexia, vomiting, polyuria and polydipsia (PUPD). A non-movable mass on the lingual aspect of the right mandible was biopsied by the referring veterinarian. Histopathology was consistent with malignant melanoma. On physical examination at VTH, a weak femoral pulse, prolonged capillary refill time and abdominal pain with palpation were present. The melanoma on the lingual surface of the right mandible was approximately 3 cm in diameter. Abnormalities detected via CBS, serum biochemistry and urinalysis revealed neutrophilic leucocytosis [13,360/µL; Reference Interval (RI) 3000-12000], hypercalcemia (17.8 mg/dl; RI 8-12), and hysosthenuria (USG 1010). A large area of bone resorption of cranial part of right mandibular body was observed at radiographic examination visible on both laterolateral and dorsoventral projections. Abdominal US and a 3- view radiography of the thorax were within normal limits. Increased ionized calcium (Ca++ 2.45 mmol/L; RI 1.25-1.50), low parathyroid hormone (PTH <3 pg/ml; RI 20-130) and normal vitamin D3 (51.60 μg/L; RI 18-58) and PTH related protein levels (0.0 pmol/l; RI 0.0-1.0) ruled out hyperparathyroidism and humoral malignancy, suggesting hypercalcemia as PNS secondary to bone resorption. The dog received saline solution, gastroprotective and antiemetic drugs (ranitidine 3 mg/kg EV BID, maropitant 1 mg/kg SC SID, metoclopramide 1.1 mg/kg/die CRI) and restart eating during the second day of hospitalization despite high Ca++ levels (2.16 mmol/L; RI 1.25-1.50). One administration of 4 mg of zoledronic acid, diluted in 100 ml of saline solution in a slow intravenous infusion over 30 minutes, was able to normalize Ca++ in three days (1.45 mmol/L; RI 1.25-1.50); the owners refuse further diagnostic and therapeutic procedures and the dogs was discharged after 4 days of hospitalization. After 8 weeks of follow-up the dog remains normocalcemic and it was active, with a good appetite and without PUPD. In conclusion, hypercalcaemia is a rare complication of melanoma and, in both humans and dogs, is essentially due to aggressive bone lysis with an uncoupling in bone turnover. As observed in the present case, bisphosphonates such as zoledronic acid can offer short-term palliation.
[1] Bergman PJ. Paraneoplastic hypercalcemia. Topics in Compan An Med, 27:156-158, 2012. [2] Pressler BM et al. Hypercalcemia and high parathyroid hormone-related protein concentration associated with malignant melanoma in a dog. J Am Vet Med Assoc, 221(2):263-255, 2002. [3] des Grottes JM et al. Hypercalcaemia of melanoma: incidence, pathogenesis and therapy with bisphosphonates. Melanoma Res, 11(5):477-482, 2001.