Investigations in patients presenting with AIHA
| Diagnostic tests . | Indication for tests . |
|---|---|
| Primary evaluation | |
| Hemolytic screen | |
| FBC, blood smear, LDH, haptoglobin, bilirubin, DAT, reticulocyte count with or without urine for hemosiderin or urine dipstick for microscopy | |
| Detection of underlying disorders (investigation of AIHA) | |
| Serum Igs and electrophoresis with immunofixation* | |
| HIV, HBV, HCV | |
| Anti-dsDNA, ANA | |
| CT chest, abdomen, and pelvis | |
| Additional investigation in selected patients with AIHA | |
| Bone marrow examination | CAD, age ≥ 60 years, features in history, examination, FBC or smear suggesting possible marrow infiltration |
| U&E, LFT, clotting, BP, urine dipstick | If pregnant or thrombocytopenic, to exclude DIC or pregnancy-associated TMA |
| Infection screening | Dependent on symptoms, travel history, and age |
| Peripheral T-cell subsets, creatinine, LFT, clotting | All children and if suspected Evans syndrome |
| Parvovirus, hematinics | If reticulocytopenia |
| Additional serological investigation in selected patients with AIHA | |
| DAggT | If DAT positive for C3d ± IgG |
| Cold antibody titer | If DAggT positive |
| Monospecific DAT for IgM, G, A, C3d | If DAT-negative AIHA suspected |
| Red cell eluate | If (monospecific) DAT-negative AIHA suspected |
| Donath Landsteiner | If DAT is positive for C3d ± IgG and |
| i) DAggT-negative or insignificant CAs and | |
| ii) Age < 18 y or hemoglobinuria or cold-associated symptoms or atypical serology | |
| Thermal range of cold antibody | If clinical significance of cold autoagglutinin unclear |
| Diagnostic tests . | Indication for tests . |
|---|---|
| Primary evaluation | |
| Hemolytic screen | |
| FBC, blood smear, LDH, haptoglobin, bilirubin, DAT, reticulocyte count with or without urine for hemosiderin or urine dipstick for microscopy | |
| Detection of underlying disorders (investigation of AIHA) | |
| Serum Igs and electrophoresis with immunofixation* | |
| HIV, HBV, HCV | |
| Anti-dsDNA, ANA | |
| CT chest, abdomen, and pelvis | |
| Additional investigation in selected patients with AIHA | |
| Bone marrow examination | CAD, age ≥ 60 years, features in history, examination, FBC or smear suggesting possible marrow infiltration |
| U&E, LFT, clotting, BP, urine dipstick | If pregnant or thrombocytopenic, to exclude DIC or pregnancy-associated TMA |
| Infection screening | Dependent on symptoms, travel history, and age |
| Peripheral T-cell subsets, creatinine, LFT, clotting | All children and if suspected Evans syndrome |
| Parvovirus, hematinics | If reticulocytopenia |
| Additional serological investigation in selected patients with AIHA | |
| DAggT | If DAT positive for C3d ± IgG |
| Cold antibody titer | If DAggT positive |
| Monospecific DAT for IgM, G, A, C3d | If DAT-negative AIHA suspected |
| Red cell eluate | If (monospecific) DAT-negative AIHA suspected |
| Donath Landsteiner | If DAT is positive for C3d ± IgG and |
| i) DAggT-negative or insignificant CAs and | |
| ii) Age < 18 y or hemoglobinuria or cold-associated symptoms or atypical serology | |
| Thermal range of cold antibody | If clinical significance of cold autoagglutinin unclear |
ANA, antinuclear antibody; BP, blood pressure; CAD, cold agglutinin disease; CAs, cold agglutinins; CT, computerized tomography; DAggT, direct agglutination test; DIC, disseminated intravascular coagulation; dsDNA, double-stranded DNA; FBC, full blood count; HBV, hepatitis B virus; HCV, hepatitis C virus; LFT, liver function tests; TMA, thrombotic microangiopathy; U&E, urea and electrolytes.
If a cold autoantibody suspected, keep sample at 37°C until serum has been separated.
Modified from Hill et al, with permission.12