Click on a hyperlink.
Clinical vignette 1
A 52 year-old male presents with a chief complaint of fatigue, and you notice marked pallor of the conjunctival membranes on physical examination. You order a complete blood count (CBC).
Laboratory findings - CBC
| Component | Value | Normal Range | Differential | Value | Normal Range | |
| WBC | 8.2 | 4-10 thousand/ul | NEUT | 65 | 41-77% | |
| RBC | 3.7 | 4.5-5.9 million/ul | BAND | 3 | 0-2% | |
| HGB | 6.9 | 14-17.5 g/dl | LYMPH | 25 | 24-44% | |
| HCT | 23.3 | 42-50% | MONO | 7 | 4-12% | |
| MCH | 18.6 | 27.5-33.2 pg/RBC | ||||
| MCHC | 29.7 | 33.4-35.5 gm/dl | ||||
| MCV | 62 | 80-96 fl/RBC | ||||
| RDW | 20.6 | 11.5-14.5 | ||||
| Platelets | 518 | 150-400/ul |
Physical examination showed marked swelling and erythema of the left knee, and range of motion was markedly decreased. Small resolving ecchymoses were noted on the arms and legs. Aspiration of the knee joint showed bloody fluid.
Laboratory Findings: hemoglobin 140 g/L (reference range 140-180 g/L), white cells 8 x 109/L (normal 4 .5-11 x 109/L), platelets 250 x 109/L (normal 150-450 x 109/L), prothrombin time 12 sec. (normal 10-13 sec), activated partial thromboplastin time 65 sec. (normal 25 - 35 sec), bleeding time 6 minutes (normal 2-8 minutes), fibrin degradation products <10 mg/L (normal <10 mg/L), Factor VIII 5% (normal 50-150%), Factor IX 88% (normal 50-150%), von Willebrand factor 100 U/L (normal 50-150 U/L).
Lab studies: hemoglobin 80 g/L (normal 120-160 g/L), white cells 10 x 109/L (normal 4.5-11 x 109/L), platelets 15 x 109/uL (normal 150-450 x 109/L), prothrombin time 13 seconds (normal 10-13 sec.), activated partial thromboplastin time 32 seconds (normal 25-35 sec.), fibrin degradation products <10 mg/L (normal <10 mg/L), bleeding time 15 minutes (normal 2-8 min.), lactate dehydrogenase 264 U/L (normal 38-62 U/L), aerobic and anaerobic blood cultures were negative. Blood smear showed numerous red cell fragments (schistocytes).
The patient was admitted to the hospital and daily plasmapheresis was performed with fresh frozen plasma as the replacement fluid. Over a period of 10 days the patients symptoms completely resolved, and the platelet count increased to 150 x 109/L and the lactate dehydrogenase levels normalized. Plasmapheresis was discontinued after the tenth procedure.
Lab studies: hemoglobin 82 g/L (normal 140-180 g/L), white cells 12 x 109/L (normal 4.5-11 x 109/L), platelets 10 x 109/L (normal 150-450 x 109/L), prothrombin time 20 seconds (normal 10-13 sec.), activated partial thromboplastin time 55 seconds (normal 25-35 sec.), fibrin degradation products >80 mg/L (normal <10 mg/L), bleeding time 20 minutes (normal 2-8 minutes), fibrinogen 0.6 g/L (normal 2.0-4.0 g/L), blood smear showed numerous atypical promyelocytes with folded nuclei and abundant cytoplasm containing numerous large purple granules and Auer rods.