Pegylated-l-asparaginase therapy for feline large cell lymphoma: 82 cases (2017-2020)

OBJECTIVES: The present study aimed to investigate pegylated-l-asparaginase monotherapy for feline large cell lymphoma as a potential alternative to palliative corticosteroids treatment in animals whose owners declined cytotoxic chemotherapy. METHODS: A retrospective, descriptive case series of cats treated initially with pegylated-l-asparaginase as a sole therapy for feline large cell lymphoma is reported. The treatment protocol consisted of 12 intramuscular injections of pegylated-l-asparaginase with increasing intervals. If cats were unresponsive to pegylated-l-asparaginase monotherapy, a second-line treatment was initiated. Signalment, origin of lymphoma, staging, treatment, possible adverse events and follow-up data were extracted from the medical records. Responses and survival data were analysed. RESULTS: Eighty-two cats with lymphoma of five different anatomic types were included: alimentary, abdominal extra-alimentary, peripheral nodal, nasal/nasopharyngeal and other (mediastinal, renal [solitary] and miscellaneous combined in one group for analytical purposes). The response rate was 74.1% (95% confidence interval = 63.4-83.5) with 38.3% (95% confidence interval = 27.8-48.8) in complete remission. The median disease-free period and calculated overall survival time were 70 days (12-1702+) and 79 days (1-1715+), respectively. The response rate was significantly correlated with the origin of the lymphoma and the combined group had a significantly lower response rate ( P  = 0.035). Twenty-four cats were also treated with corticosteroids. There was no significant difference in outcomes between the group treated with or without corticosteroids. Adverse events were present in a small number of cats (14/82). The majority of these adverse events were mild to moderate in 5/14 cats; however, the adverse events were severe enough to cause discontinuation of therapy. CONCLUSIONS AND RELEVANCE: Based on the response rate and median disease-free period, treatment with pegylated-l-asparaginase is inferior when compared with historical chemotherapy protocols. However, some cats demonstrated an exceptional long disease-free period. Therefore, pegylated-l-asparaginase could be offered as an alternative to corticosteroid therapy alone. Further studies are needed to evaluate the additional benefit over palliative corticosteroid monotherapy

Studying Cat (Felis catus) Diabetes: Beware of the Acromegalic Imposter

Naturally occurring diabetes mellitus (DM) is common in domestic cats (Felis catus). It has been proposed as a model for human Type 2 DM given many shared features. Small case studies demonstrate feline DM also occurs as a result of insulin resistance due to a somatotrophinoma. The current study estimates the prevalence of hypersomatotropism or acromegaly in the largest cohort of diabetic cats to date, evaluates clinical presentation and ease of recognition. Diabetic cats were screened for hypersomatotropism using serum total insulin-like growth factor-1 (IGF-1; radioimmunoassay), followed by further evaluation of a subset of cases with suggestive IGF-1 (>1000 ng/ml) through pituitary imaging and/ or histopathology. Clinicians indicated pre-test suspicion for hypersomatotropism. In total 1221 diabetic cats were screened; 319 (26.1%) demonstrated a serum IGF-1>1000 ng/ml (95% confidence interval: 23.6-28.6%). Of these cats a subset of 63 (20%) underwent pituitary imaging and 56/63 (89%) had a pituitary tumour on computed tomography; an additional three on magnetic resonance imaging and one on necropsy. These data suggest a positive predictive value of serum IGF-1 for hypersomatotropism of 95% (95% confidence interval: 90-100%), thus suggesting the overall hypersomatotropism prevalence among UK diabetic cats to be 24.8% (95% confidence interval: 21.2-28.6%). Only 24% of clinicians indicated a strong pre-test suspicion; most hypersomatotropism cats did not display typical phenotypical acromegaly signs. The current data suggest hypersomatotropism screening should be considered when studying diabetic cats and opportunities exist for comparative acromegaly research, especially in light of the many detected communalities with the human disease

Agreeing Language in Veterinary Endocrinology (ALIVE): Diabetes mellitus - a modified Delphi-method-based system to create consensus disease definitions

[No abstract

Agreeing language in veterinary endocrinology (ALIVE): diabetes mellitus - a modified Delphi-method-based system to create consensus disease definitions

[No abstract

Overview of the screening results.

<p>In total 1221 cats with diabetes mellitus were screened for HS; the results are summarised in this figure. IGF-1: insulin-like growth factor-1; CT: computed tomography; MRI: magnetic resonance imaging; HS: hypersomatotropism; n: number of animals; PME: post-mortem evaluation.</p

Example of prognathia inferior.

<p>This figure shows a cat with confirmed acromegaly demonstrating prognathia inferior (a), including a sagittal CT view of the cat’s head illustrating this conformational change further (b).</p

Paws of an overtly acromegalic cat.

<p>This figure shows a cat with confirmed acromegaly demonstrating so-called clubbed paws; enlargement of the paws due to acromegaly.</p

Microscopic image of the anterior pituitary of a diabetic cat with confirmed HS.

<p>A clear predominance of acidophils is apparent in the sections of the pars distalis of the anterior pituitary (H&E staining; main image: objective 100x; inset: objective: 400x)</p

Table comparing basic characteristics of diabetic cats with excessively high (>1000ng/ml) and low (<1000 ng/ml) serum total insulin-like growth factor-1 (IGF-1) concentration.

<p>^aDomestic Short Hair Cat</p><p>^bDomestic Long Hair Cat</p><p>^cBritish Short Hair Cat</p><p>^dmale neutered</p><p>^emale entire</p><p>^ffemale neutered</p><p>^gfemale entire.</p><p>Table comparing basic characteristics of diabetic cats with excessively high (>1000ng/ml) and low (<1000 ng/ml) serum total insulin-like growth factor-1 (IGF-1) concentration.</p