Systematic Review of Prognostic Factors for Mortality in Dogs with Immune‐mediated Hemolytic Anemia

Abstract

BackgroundTreatment of dogs with primary immune‐mediated hemolytic anemia (IMHA) is difficult and frequently unrewarding. Prognostic factors have been evaluated in a number of previous studies, and identification of such factors would be beneficial to enable selection of appropriate therapeutic regimens and supportive care.ObjectivesThe aim of the current study was to undertake a critical appraisal of the risk of bias in evidence relating to prognostic indicators for mortality in dogs with IMHA.AnimalsThree hundred and eighty client‐owned dogs with spontaneous primary idiopathic IMHA reported in 6 previous studies.MethodsA systematic review was conducted to evaluate evidence relating to prognostic factors for mortality in dogs with primary IMHA. Search tools were employed to identify articles and a validated appraisal tool was used to assess the quality of individual studies by considering inclusion and exclusion criteria, measurement of prognostic, outcome and confounding variables, and statistical methods.ResultsFew studies evaluated prognostic indicators for IMHA in dogs, and all of these suffered from methodologic flaws in at least 1 major area. Fifteen different variables were identified as prognostic indicators, with 2 variables identified by >1 study.Conclusions and Clinical ImportanceThere are few pieces of high‐quality evidence available to enable estimation of prognosis for dogs presenting with primary IMHA.

ACVIM consensus statement on the treatment of immune‐mediated hemolytic anemia in dogs

“…Numerous studies have evaluated possible prognostic factors for dogs with IMHA, either by exploring associations between survival and a single candidate variable, or by constructing a multivariable model to account for possible confounding factors. Among the latter models, increased serum bilirubin concentration (or clinical icterus) and increased serum urea or BUN concentration were identified as independent predictors of mortality in 2 studies of different patient populations . Both prognostic factors subsequently were identified by a further study of dogs with IMHA in the United Kingdom .…”

“…RCT, randomized controlled trial as independent predictors of mortality in 2 studies of different patient populations. 51 Both prognostic factors subsequently were identified by a further study of dogs with IMHA in the United Kingdom. 52 We suggest therefore that evaluation of serum bilirubin and urea concentrations may be of greatest utility in predicting outcome for dogs with IMHA (published values shown in Table 2), although several other factors have been identified as single predictors.…”

Demographic Characteristics, Survival and Prognostic Factors for Mortality in Cats with Primary Immune‐Mediated Hemolytic Anemia

“…Age of the patient often is considered to have an impact on survival, but this variable was retained when the majority of cases were diagnosed in cats <9 years of age. Serum bilirubin concentration and clinically detectable icterus have been identified as negative prognostic factors for mortality in several studies of IMHA in dogs, 9,[30][31][32] and this result probably is related to the severity of hemolysis. Increased serum bilirubin concentration also could be associated with hepatic dysfunction caused by hypoxia and to formation of hepatic or portal thomboemboli, although the latter complication was only detected in 1 cat in this study by ultrasonography.…”

Immunsuppressive Therapie bei Hunden und Katzen. Eigenschaften von Wirkstoffen und ihre Anwendung bei verschiedenen immunvermittelten Erkrankungen

“…Der Einsatz zusätzlicher Immunsuppressiva ist bei Patienten indiziert, die diese für eine vollständige Immunsuppression benötigen, und bei Patienten, bei denen aufgrund der steroidinduzierten Nebenwirkungen eine zeitnahe Dosisreduktion der Glukokortikoide erfolgen muss (52). Eine Bilirubinämie wurde beim Hund (83,100,102) und bei der Katze (103) als negatives prognostisches Kriterium beschrieben. Weitere negative prognostische Kriterien sind ein erhöhter Blutharnstoff-Gehalt (wahrscheinlich teilweise als Ausdruck gastrointestinaler Blutungen), eine Thrombozytopenie und eine relative Hypokoagulabilität (gemessen im Thromboelastogramm) (40,41,83).…”