Relation of presenting features and clinical outcomes of 142 patients with clinically diagnosed TTP-HUS to categories of ADAMTS13 activity
. | ADAMTS13 activity . | . | . | . | |||
|---|---|---|---|---|---|---|---|
. | Less than 5% (n = 18) . | 5%-9% (n = 7) . | 10%-25% (n = 23) . | More than 25% (n = 94) . | |||
| Demographic features | |||||||
| Median age, y (minimum, maximum) | 36 (19, 71) | 52 (40, 68) | 50 (9, 85) | 51 (14, 86) | |||
| Sex, % female | 78 | 57 | 65 | 69 | |||
| Race, % African American | 50 | 29 | 13 | 14 | |||
| Obesity, % BMI ≥ 30 kg/m2 | 50 | 43 | 39 | 24 | |||
| Presenting clinical and laboratory features* | |||||||
| Severe neurologic abnormalities, % | 44 | 43 | 74 | 47 | |||
| Acute renal failure, % | 6 | 14 | 30 | 55 | |||
| Median platelet count, × 109/L (minimum, maximum) | 11 (4, 27) | 7 (2, 21) | 12 (2, 93) | 23 (1, 129) | |||
| Median hematocrit, % (minimum, maximum) | 21 (15, 30) | 24 (16, 26) | 22 (14, 29) | 22 (12, 40) | |||
| Median LDH, U/L (minimum, maximum)† | 1640 (436, 3909) | 1148 (256, 1848) | 894 (309, 9000) | 1399 (138, 12 587) | |||
| Clinical outcomes | |||||||
| Response, % (proportion) | 89 (16/18) | 71 (5/7) | 39 (9/23) | 60 (56/94) | |||
| Exacerbation, % (proportion)‡ | 56 (9/16) | 80 (4/5) | 33 (3/9) | 11 (6/56) | |||
| Median no. of plasma exchange (minimum, maximum)§ | 21 (5, 74) | 45 (2, 68) | 18 (8, 59) | 10 (0, 37) | |||
| TTP-HUS-associated death, % (proportion) | 17 (3/18) | 14 (1/7) | 61 (14/23) | 35 (33/94) | |||
| All death, % (proportion) | 17 (3/18) | 29 (2/7) | 70 (16/23) | 53 (50/94) | |||
| Relapse, % (proportion)∥ | 44 (7/16) | 17 (1/6) | 11 (1/9) | 3 (2/61) | |||
. | ADAMTS13 activity . | . | . | . | |||
|---|---|---|---|---|---|---|---|
. | Less than 5% (n = 18) . | 5%-9% (n = 7) . | 10%-25% (n = 23) . | More than 25% (n = 94) . | |||
| Demographic features | |||||||
| Median age, y (minimum, maximum) | 36 (19, 71) | 52 (40, 68) | 50 (9, 85) | 51 (14, 86) | |||
| Sex, % female | 78 | 57 | 65 | 69 | |||
| Race, % African American | 50 | 29 | 13 | 14 | |||
| Obesity, % BMI ≥ 30 kg/m2 | 50 | 43 | 39 | 24 | |||
| Presenting clinical and laboratory features* | |||||||
| Severe neurologic abnormalities, % | 44 | 43 | 74 | 47 | |||
| Acute renal failure, % | 6 | 14 | 30 | 55 | |||
| Median platelet count, × 109/L (minimum, maximum) | 11 (4, 27) | 7 (2, 21) | 12 (2, 93) | 23 (1, 129) | |||
| Median hematocrit, % (minimum, maximum) | 21 (15, 30) | 24 (16, 26) | 22 (14, 29) | 22 (12, 40) | |||
| Median LDH, U/L (minimum, maximum)† | 1640 (436, 3909) | 1148 (256, 1848) | 894 (309, 9000) | 1399 (138, 12 587) | |||
| Clinical outcomes | |||||||
| Response, % (proportion) | 89 (16/18) | 71 (5/7) | 39 (9/23) | 60 (56/94) | |||
| Exacerbation, % (proportion)‡ | 56 (9/16) | 80 (4/5) | 33 (3/9) | 11 (6/56) | |||
| Median no. of plasma exchange (minimum, maximum)§ | 21 (5, 74) | 45 (2, 68) | 18 (8, 59) | 10 (0, 37) | |||
| TTP-HUS-associated death, % (proportion) | 17 (3/18) | 14 (1/7) | 61 (14/23) | 35 (33/94) | |||
| All death, % (proportion) | 17 (3/18) | 29 (2/7) | 70 (16/23) | 53 (50/94) | |||
| Relapse, % (proportion)∥ | 44 (7/16) | 17 (1/6) | 11 (1/9) | 3 (2/61) | |||
Presenting features and clinical outcomes are defined in “Patients and methods.” All demographic and presenting feature variables were tested to determine if there was a significant difference across different ADAMTS13 categories; a significant difference was present for age, percentage of African-American race, relative frequency of acute renal failure, and platelet counts (P < .05). All demographic and presenting feature variables were also tested to determine if there was a significant linear trend across different ADAMTS13 categories; a significant linear trend was present for percentage of African-American race, percentage of obese patients, relative frequency of acute renal failure, and platelet counts (P < .05). All clinical outcome variables were tested to determine if there was a significant difference across different ADAMTS13 categories; a significant difference was present for each variable (P < .02). All clinical outcome variables were also tested to determine if there was a significant linear trend across different ADAMTS13 categories; except for death (P = .20), a significant linear trend was present for all outcome variables (P ≤ .05).
Laboratory data are the most abnormal values on the day of diagnosis ± 7 days.
Adjusted to an upper limit of normal value of 200 U/L.
The denominator is the number of patients who achieved a response.
The number of plasma exchange treatments is given for all patients who achieved a remission. One patient had no plasma exchange treatments; he had ticlopidine-associated TTP-HUS and began to improve before plasma exchange was begun; therefore, treatment was withheld.
The denominator is the number of patients who achieved a remission.