The effect of ammonia on canine polymorphonuclear cells

The Value of Ammonia as a Biomarker in Patients with Cirrhosis

Ammonia is a product of amino acid metabolism that accumulates in the blood of patients with cirrhosis and plays a pivotal role in the pathogenesis of hepatic encephalopathy (HE). Despite being one of the main drivers of brain dysfunction, for many years international societies stated that increased blood ammonia does not add any diagnostic, staging, or prognostic value for HE in patients with cirrhosis. Nonetheless, in the last decades, evidence is emerging that supports the utility of ammonia for risk stratification, but its role in guiding HE diagnosis, staging, and treatment is unclear and there is equipoise in its use in clinical practice. This review provides the latest evidence on the value of ammonia as a biomarker in patients with cirrhosis. Although correct measurement of ammonia requires disciplined sample collection, it provides extremely useful clinical guidance for the diagnosis of HE, offers prognostic information, and it defines a therapeutic target.

The Ongoing Debate of Serum Ammonia Levels in Cirrhosis: the Good, the Bad, and the Ugly

Serum ammonia testing in hepatic encephalopathy (HE) has been long debated in the field of hepatology. Although central to the pathophysiology of HE, serum ammonia testing is fraught with complexities that can lead to challenges in laboratory collection and interpretation. Although there is some disagreement across guideline organizations regarding routine testing of ammonia in HE, all acknowledge that normal values, although possible in HE, may warrant reconsideration of the diagnosis. In this study, we propose a nuanced approach to ammonia testing in HE. Serum ammonia testing provides little additional benefit in clinical scenarios with a high or low pretest probability for HE. However, if the pretest probability for HE is uncertain, a low ammonia level may reduce the posttest probability of HE. In this scenario, other etiologies of altered mental status should be explored. Future research should focus on developing a standardized approach to serum ammonia collection, processing, and interpretation.

Neutrophilia is associated with a poorer clinical outcome in dogs with chronic hepatitis

BACKGROUND

Liver disease is a common cause of morbidity and mortality in dogs. Currently, it is challenging to prognosticate in these cases. The aim of this study was to evaluate the utility of the haematological variables in dogs with chronic hepatitis.

METHODS

Dogs with chronic hepatitis confirmed on histopathology had presenting haematological values retrospectively obtained and evaluated against survival time. Eighty-two dogs met the inclusion criteria and their data analysed.

RESULTS

Neutrophilic patients, with a count greater than 12×10⁹/l, controlled for sex and age, had a shorter survival time (P≤0.01). In dogs, neutrophilia at presentation predicted a poor outcome, whereas the other haematological parameters were not prognostically informative. When the dogs were split into even quarters on the basis of their neutrophil count, those within the higher quartiles had poorer survival times. Neutrophilia was associated with a poorer survival time in comparison to those patients with a lower count.

CONCLUSION

The relationship between neutrophils, inflammation and clinical outcome is deserving of future study in dogs with chronic hepatitis.