A 49-year-old female presents with confusion. The results of her blood tests are as follows:
|
Parameter |
Patient Value |
Normal Adult Range |
|
Haemoglobin |
86 q/L* |
135 - 180 |
|
White Cell Count |
11.2 x 109/L* |
4.0 - 11.0 |
|
Platelets |
23 x 109/L* |
150 - 400 |
|
Prothrombin time |
14.0 sec |
12.0 - 16.5 |
|
Activated partial thromboplastin time |
35.0 sec |
27.0 - 38.5 |
|
Fibrinogen |
2.1 q/L |
2.0 - 4.0 |
|
Thrombin time |
14.0 sec* |
11.5 - 13.5 |
|
Urea |
12.1 mmol/L* |
3.0 - 8.0 |
|
Creatinine |
356 µmol/L* |
45 - 90 |
|
Lactate dehydrogenase |
2342 U/L* |
140 - 280 |
a) Give the likely diagnosis. (20% marks)
b) Give an additional test to support your diagnosis. (10% marks)
a) Thrombotic thrombocytopaenic purpura
Haemolytic-uraemic syndrome
Systemic lupus erythromatosis
MAHA (1 mark only)
b) ADAMTS13 (TTP)
Positive Shiga toxin / Entero-haemorrhagic E coli test (HUS)
ANA / anti-dsDNA (SLE)
Blood film
Reticulocyte count
Haptoglobins
a)
The diagnosis of TTP/HUS suggests itself, even though the "pentad" of symptoms is incomplete:
The low-ish fibrinogen suggests that a TTP-related excess of vWF has produced a systemic prothrombotic state, with microvascular thrombosis consuming all the fibrinogen.
b)
ADAMTS-13 level is of course the most important supportive test. The relevanc of this protein is discussed in the chapter on TTP/HUS.
George, James N. "Thrombotic thrombocytopenic purpura." New England Journal of Medicine 354.18 (2006): 1927-1935.