Anemia – What do you mean it’s not IMHA??? Jason M. Eberhardt DVM, MS, DACVIM S Overview S One of the most common CBC abnormalities S 10-30% of patients S Why is it still so confusing? S Back to basics S Systematic approach to anemia S Avoiding common pitfalls Some thoughts… S “You need to have the correct diagnosis before you can recommend the correct treatment.” S “If you always have the correct diagnosis then you’re not a really veterinarian…you’re probably a breeder.” S “You need to run a minimum of 5 diagnostic tests prior to starting steroids…” Definitions S Mean Corpuscular Volume (MCV) – Avg. RBC size S Macrocytosis S Microcytosis S Normocytic S Mean corpuscular Hgb concentration (MCHC) – [ ] of Hgb vol. RBC S Hypochromic S Normochromic S Macrochromic S Reticulocytes – Immature RBCs released from B.M. early S Normoblasts/metarubricytes – nucleated erythrocytes Definitions continued… S Poikilocytosis – Variation of RBC shape S Rouleaux – Stacks of coins S Small amount is normal S Increased fibrinogen or acute phase proteins S Typically seen in inflammatory conditions S Autoagglutination – Aggregate in grapelike clusters S Must be differentiated from rouleaux S Rouleaux disperses when blood is mixed with saline Rouleaux or Autoagglutination Rouleaux Autoagglutination Before I go any further… S Where do I start……. S Back to basics!!! The first step… S Remember the Total Protein!!! S It’s the other half of “blood” S It’s cheap! S It’s fast S DO NOT OVERLOOK! S Are just the RBCs being affected or the plasma as well? The next steps… S Morphologic classification S RBC indices S Bone marrow response S Regenerative vs. Non-regenerative S Description of poikilocytosis? S Macrocytic, hypochromic, regenerative anemia with marked spherocytosis Morphological classification S Usage of RBC indices (MCV/MCHC) to “describe” the RBCs. S Remember MCV/MCHC are MEAN calculations S Large # of RBCs affected prior to increases/decreases S Allows characterization of anemia into a category S Helps with ranking differential diagnoses S Are found on nearly all in-house CBC units Normocytic normochromic S Most common S “Normal” RBCs S Most commonly denotes a non-regenerative anemia S Usually lacks RBC morphology changes S “Pre-regenerative” S First 1-3 days of acute loss/lysis Macrocytic hypochromic S Usually indicates a regenerative anemia S Reticulocytes are relatively larger then mature RBCs S Hypochromic because Hgb synthesis is not complete S Only 8% of 6752 patients with reg. anemia had both increased MCV & decreased MCHC DiNicola et al. Macrocytic normochromic S Usually misclassification due to insensitivity of MCV/MCHC S Autoagglutination? S Feline Leukemia S Poodles – Congenital dyserythropoiesis S Not anemic S Large problem in humans S B12 &/or folate deficiency S Role in veterinary medicine is questionable Microcytic hypochromic S Consistent with an iron deficiency anemia S Inadequate amount of Hgb is produced S Typically seen in chronic conditions S GI blood loss S Severe parasitism S PSS & Hepatic atrophy S Myelodysplastic syndromes S Congenital: Akitas, Shiba Inu, Chow breeds S Not typically hypochromic Bone marrow response S Is there a regenerative response? S Evaluation of reticulocytosis S No reticulocytosis/polychromasia expected during first 1-3 days (maybe not at all if anemia stays mild) S Response peaks 4-5 days (with normal B.M.) S Erythrocyte indices start to change 7-14 days What is consider regenerative??? S Normal patient should have <45,000-60,000 absolute retic count S Absolute counts S 60,000-150,000 Early/mild response S 150,000-250,000 Mild-moderate S >250,000-500,000 Moderate-Marked S Relative % S 1-4 % - Mild S 5-20 % - Moderate S > 20 % - Marked Regenerative anemia S Loss vs. Lysis S LOOK AT TOTAL PROTEIN!!!! S External blood loss S Low to low-normal T.P. S Hemolytic disease S High to high-normal T.P. Acute external blood loss S PCV does not fully reflect severity first 1-3 days S Reticulocytosis should start by day 3 S Peak reticulocytes day 4-7 S PCV increases to low normal w/in 2 wks S May take up to 4-5 weeks to return to normal S Mild anemia does not stimulate strong erythropoietin release Chronic blood loss S Iron deficiency and negative protein balance develops after “several” weeks in adults S Occurs more rapidly in young animals (low iron stores) S Initially non/”pre” regenerative S Period of regenerative anemia depending on severity S Eventually returns to being poorly/non-regenerative S Often have thrombocytosis S Remember RBC indices do not change for 7-14 days S Getting blood transfusions??? Hemolytic anemia S Hemolysis is a mechanism NOT a “disease” S Lots of “non” immune mediated causes S Low serum phosphorus S Normal to increased T.P. S Spherocytosis and/or autoagglutination S Over interpretation is common S Can be seen in diseases that are not “primary” S Positive Coomb’s Test? Direct Coomb’s Test S Identifies presence antibodies/compliment on RBCs S They may/may not actually be directed towards RBCs S This may/may not actually cause damage to RBCs S Neither highly specific or sensitive for IMHA S Positive in 60-70% of cases S Positive results – should have other evidence of IMHA S Effect of steroids? S **NOTE** – What is the end point of the test????? Breaking it down… S Try to subclassify into intravascular vs. extravascular S Alters differential diagnosis S Intravascular – Rapid breakdown in vascular system S S S Pink urine, pink serum Hemoglobinuria best indicator Hyperbilirubinemia typically more profound then in extravascular S Extravascular – removal of RBCs by spleen, liver, B.M. S S More common Often has icterus, splenomegaly, hepatomegaly Immune mediated S “Immune-mediated” is a mechanism NOT a disease. S Can be 2nd to a number of possible causes S Infectious – Babesiosis, Ehrlichiosis, Leishmaniasis, Rickettsioses, Mycoplasma haemofelis, FeLV S Neoplasia S Drugs S Can be initially non-regenerative (esp. in cats) “Penny” 6 year FS Cocker S Presented for severe lethargy, “yellow skin” and “peeing blood” S Severe, macrocytic, normochromic strongly regenerative anemia with mild-moderate spherocytosis S Slide agglutination negative S High total protein S Abdominal ultrasound WNL S Infectious disease titers all negative The “Penny” dilemma S Needed multiple transfusion in a 5-6 day period S Continued to have hemolysis despite aggressive immunosuppressive therapy S Where do we go from here??? S “Peeing” blood – hemoglobinuria S Intravascular hemolysis Intravascular hemolysis S Immune mediated S Phosphofructokinase deficiency S Eng. Springers, Amer. Cockers S Babesia infection S Snake envenomation S Heavy metal to toxicity S Zinc S Copper “Penny” 6 yr FS Cocker Spaniel S Presented for severe lethargy, yellow skin and “peeing blood” S Severe, macrocytic, normochromic strongly regenerative anemia with mild-moderate spherocytes S Abdominal ultrasound WNL S Infectious disease titers all negative “Sheldon” 9 yr MC Jack Russell S Presented with clinical evidence of anemia S Severe leukocytosis (54,000), severe anemia (9%), high normal platelets, mild-moderate reticulocytosis S Total Protein – 4.9 g/dL S VF, Ehr. Neg. IHMA??? S Started on prednisone, cyclosporine, doxycycline S Needed 2nd transfusion 1 week later S Added azathioprine S PCV still low 2 weeks later S Chest rads and abd. u/s WNL S Increased prednisone, continued on cyclosporine and azathioprine S 3rd transfusion in 4 weeks S Added leflunomide S Repeat abdominal ultrasound WNL More anemia!!! S Initial PCV/TP at EAC S 12%/4.8 S Reference lab work S Hypoalbuminemia (2.6 g/dL), globulin WNL (1.7 g/dL), BUN increased (mild), Total bilirubin (mild) S Inflammatory leukogram S Severe reticulocytosis What’s going on??? S Horrible IMHA??? S Another type of hemolytic anemia? S GI bleeding (from prednisone?, GI mass?) S Diagnostic plan??????????? S Explain the decreased total protein Non-regenerative anemia S Very common!!! S Usually normocytic normochromic S Microcytic, hypochromic anemias S Usually no poikilocytosis S Huge majority are mild-moderate in severity S 2nd to systemic disease Before going any further… S Is neutropenia and/or thrombocytopenia also present? S What is the duration of clinical signs? S How severe are the clinical signs? I need more RBCs… S Mild-moderate NR anemia S Search for an underlying disease first S Anemia of chronic/inflammatory disease S Neoplasia, renal disease, hepatic disease, infectious, inflammatory, endocrine S Drugs Severe non-regenerative anemia S Toxicity S Estrogen? S Drugs S Renal disease S More than just decreased erythropoietin S Chronic dz, decr. RBC lifespan, ineffective production, blood loss Why can’t it be easy??? S Bone marrow exam S Took a long time to develop S Can take even longer to resolve S Can still be very confusing and frustrating Bone Marrow disease S Immune mediated S Maturation arrest vs. Pure Red Cell Aplasia S Myelophthisic syndromes - multiple cell lines often affected S Aplastic anemia – B.M. replaced by fat S Can be 2nd to chronic ehrlichiosis S Myelofibrosis – B.M. replaced by fibrous S Myelonecrosis – Drugs, toxins, viral S Neoplasia “Howard” 9 yr MN DSH S Progressive lethargy, wt. loss for several weeks S Marked (12%), macrocytic, normochromic anemia S Total protein 6.2 g/dL S Absolute reticulocyte count 40,000 S S Retic. total 2% Corrected 0.65% S FelV/FIV negative S Chest radiographs, abdominal ultrasound WNL Why cats are not small dogs… S 50% of cats with immune mediated disease initially had a non-regenerative response Kohn et al. 2006 S 2/3 were <3 years (range was 1-9 yr) S Bone marrow disease – 53% S Infectious – 22% S Hemolysis – 11% S Immune Mediated – 6% S Severity of anemia associated with B.M. disease Korman et al. 2013 Bone marrow or bust S Owner noticed gradual decline S More consistent with non-regenerative disease S Transfusion S Recheck 2-3 days later vs. bone marrow now S Marked erythroid hypoplasia/aplasia S Immune mediated vs. FelV S Bone marrow IFA positive for FelV Stutzer et al. 2010 RBC shape descriptions S Many have little/no clinical significance S Anisocytosis, elliptocytes, codocytes, leptocytes, *echinocytes* S Spherocytes – Evidence of hemolysis S Acanthocytes - Hemangiosarcoma, hepatic dz S Schistocytes - DIC, Fe def, CHF, myelofibrosis, hemangiosarcoma, other neoplasia Summary S Anemia is a common abnormality S Cause can often be elusive S Vital to approach systematically S RBC indices, bone marrow response, poikilocytosis S DON’T FORGET THE TOTAL PROTEIN!!! QUESTIONS???