Therapeutic plasma exchange in patients with thrombotic thrombocytopenic purpura–hemolytic uremic syndrome: the 10‐year experience of a single center

Figures & data

Table 1. Baseline characteristics

Characteristics		Value
Age (years)	Median (range)	47 (17–81)
Gender, n (%)	Male	20 (38·5)
	Female	32 (61·5)
Hemoglobin (g/dl)	Median (range)	7·6 (4·4–11·0)
Platelet count (×10^9/l)	Median (range)	30 (4–126)
Creatinine (mg/dl)	Median (range)	2·5 (0·6–10·6)
Fever (>38°C), n (%)	Present (%)	23 (44·2)
	Absent (%)	29 (55·8)
Neurological abnormalities, n (%)	Present	32 (61·6)
	Major*	23 (44·2)
	Minor^†	9 (17·3)
	Absent	20 (38·4)
LDH (IU/l)	Median (range)	788 (271–5176)
Etiology, n (%)	Idiopathic	14 (26·9)
	Hematopoietic stem cell transplantation	10 (19·2)
	Pregnancy	3 (5·8)
	Drugs	13 (25·0)
	Mitomycin C	8 (15·4)
	Cyclosporin A	1 (1·9)
	Tacrolimus	2 (3·8)
	Clopidogrel	1 (1·9)
	Gemcitabine	1 (1·9)
	Bloody diarrhea	2 (3·8)
	Presence of an additional disorder	10 (19·2)
	Malignancy	6 (11·5)
	Autoimmune disease	3 (5·8)
	After surgery	1 (1·9)

Note: LDH denotes lactate dehydrogenase.

*Major neurological abnormalities were defined as severe abnormalities such as stroke, coma, seizure, or fluctuating focal signs.

^†Minor neurological abnormalities were defined as less severe abnormalities such as headache, dizziness, or mental status changes with transient confusion.

Table 2. Analysis of factors associated with remission after therapeutic plasma exchange

Characteristics		RR (%)	P
Age (year)	<60	52·5	0·743
	⩾60	41·7
Gender	Male	25·0	0·009
	Female	65·6
Hemoglobin (g/dl)	<9·0	46·2	0·523
	⩾9·0	61·5
Baseline platelet (×10^9/l)	<20	47·1	1·000
	⩾20	51·4
Creatinine (mg/dl)	<1·5	28·6	0·116
	⩾1·5	57·9
Fever (>38°C)	Absent	62·1	0·093
	Present	34·8
Neurological symptoms	Absent	55·0	0·776
	Present	46·9
Etiology	Idiopathic	71·4	0·003
	HSCT	0
	Pregnancy	100
	Drugs	53·8
	Bloody diarrhea	100
	Presence of an additional disorder	40·0

Note: RR: remission rate; CI: confidence interval; HSCT: hematopoietic stem cell transplantation.

Figure 1. Overall survival varied by etiology. Patients with hematopoietic stem cell transplantation‐related TTP–HUS had significantly shorter overall survival than those with the other etiologies (P = 0·001).

Table 3. Analysis of risk factors associated with the overall survival

Characteristics		OS (95% CI)	HR (95% CI)	P	Adjusted HR (95% CI)	P
Age (year)	<60	18·2	1		…	…
	⩾60	4·3 (0·0–9·6)	1·23 (0·54–2·79)	0·619
Sex	Male	1·6 (0·2–3·0)	1		…	…
	Female	23·3	0·60 (0·29–1·25)	0·169
Hemoglobin (g/dl)	<9·0	4·9 (0·0–24·4)	1		…	…
	⩾9·0	23·3	0·82 (0·35–1·92)	0·650
Baseline platelet (×10^9/l)	<20	5·2 (0·0–25·1)	1		…	…
	⩾20	5·5 (0·0–34·2)	1·00 (0·46–2·14)	0·996
Creatinine (mg/dl)	<1·5	1·6 (0·0–3·4)	1		…	…
	⩾1·5	23·3	0·59 (0·28–1·26)	0·185
Fever (>38°C)	Absent	Not reached	1		1
	Present	0·8 (0·0–2·3)	2·24 (1·22–4·95)	0·024	1·96 (0·92–4·17)	0·081
Neurological symptoms	Absent	Not reached	1		…	…
	Present	1·7 (0·0–6·2)	2·35 (0·98–5·01)	0·057
Etiology	Idiopathic	Not reached	1		1
	HSCT	0·6 (0·0–1·4)	7·29 (2·34–22·69)	0·001	6·50 (2·08–20·32)	0·001
	Pregnancy	Not reached	0·69 (0·08–5·90)	0·732	0·67 (0·08–5·72)	0·710
	Drugs	Not reached	1·04 (0·30–3·59)	0·952	1·07 (0·31–3·70)	0·917
	Bloody diarrhea	5·2	1·52 (0·18–13·14)	0·705	1·41 (0·16–12·23)	0·757
	Presence of an additional disorder	0·6 (0·0–2·8)	2·72 (0·86–8·60)	0·088	2·57 (0·81–8·13)	0·108

Note: OS: overall survival in months; CI: confidence interval; HR: hazard ratio; HSCT: hematopoietic stem cell transplantation.

Table 4. Adverse events associated with therapeutic plasma exchange

Adverse events	No. of patients (%)	No. of events (%)	Events requiring treatment (%)	Events requiring ICU care (%)
Allergic reactions
Urticaria	12 (23·1%)	22 (6·2%)	16 (4·5%)	0 (0%)
Itching without urticaria	6 (11·5%)	14 (4·0%)	8 (2·3%)	0 (0%)
Edema	2 (3·8%)	2 (0·6%)	1 (0·3%)	0 (0%)
Fever	1 (1·9%)	1 (0·3%)	0 (0%)	0 (0%)
Shivering	1 (1·9%)	1 (0·3%)	1 (0·3%)	0 (0%)
Chest discomfort*	4 (7·7%)	5 (1·4%)	0 (0%)	0 (0%)
Abdominal discomfort^†	4 (7·7%)	6 (1·7%)	0 (0%)	0 (0%)
Dyspnea	3 (5·8%)	3 (0·8%)	2 (0·6%)	2 (0·6%)
Paresthesia	3 (5·8%)	9 (2·5%)	6 (1·7%)	0 (0%)
Headache	3 (5·8%)	3 (0·8%)	3 (0·8%)	0 (0%)
Arm pain	1 (1·9%)	1 (0·3%)	0 (0%)	0 (0%)

Note: ICU: intensive care unit.

*Chest discomfort includes palpitation, arrhythmia, and the other vague symptoms.

^†Abdominal discomfort includes nausea, vomiting, and the other vague symptoms.