Amanda S. had no prior chronic illness. Breast‑implant surgery with
liposculpture a year ago was uneventful. Four months later she developed an upper respiratory
tract infection, and about three weeks after recovering came severe headaches and
hypertensive crises that took her to the emergency department more than once. She was
started on olmesartan, amlodipine and bisoprolol.
At six months post‑surgery, cardiology referred her to nephrology for
persistent hypertension and a rising creatinine. Renal function deteriorated despite blood
pressure control — creatinine 2.21 mg/dL, then end‑stage kidney disease and
dialysis, with severe anaemia at 6.9 g/dL needing erythropoietin‑stimulating agents
a month after starting.
The renal biopsy showed significant endothelins, suggestive of vascular injury.
She reports persistent fatigue and loss of appetite. The cause of the renal deterioration
is unexplained.
Age · sex
34, female
Weight · BMI
75 kg · 23.1
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Case · Workup
The triad is there. The schistocytes are not.
Anaemia, thrombocytopenia, low haptoglobin at 16 mg/dL and LDH at 334 U/L
— microangiopathic haemolysis with kidney injury. But the smear shows no
schistocytes, the direct Coombs is negative, and the hallmark that usually announces
thrombotic microangiopathy is missing.
Serology is unrevealing: HIV, HCV, HBsAg, VDRL, FAN, anti‑dsDNA,
antiphospholipids and anti‑Scl‑70 all negative or non‑reactive; the full
antibody panel likewise. C3 is low and falling — 78 then 52 mg/dL — with C4
normal, the pattern of alternative‑pathway activation.
The biopsy reports capillary loops with double contours, arteriolar walls thickened
with reduced lumen, and moderate fibrous intimal hyperplasia: primary vascular involvement,
thrombotic microangiopathy in an organizing phase.
ADAMTS13 activity
100 %
C3 · C4
52 · 35 mg/dL
Schistocytes
Negative
Genetics
Heterozygous C3 variant
Case · Decision
What is the diagnosis?
Silicone implants, a respiratory infection, a hypertensive emergency and a
complement variant all arrived together. Choose one.
Select a diagnosis to continue
Case · Verdict
ADAMTS13 at 100% settles most of it.
AAtypical haemolytic uremic syndrome (aHUS)CorrectA heterozygous C3 variant indicates primary aHUS from complement dysregulation, and many patients with a complement risk factor need a secondary trigger — an infection or other stressor — for it to manifest (Afshar‑Kharghan, 2016; Laurence J, et al. 2016).
BThrombotic thrombocytopenic purpura (TTP)Not the diagnosisSevere ADAMTS13 deficiency, below 10 IU/dL, is what indicates TTP. Amanda's activity is 100%; above 10% supports aHUS instead (Arnold DM, et al. 2017; Laurence J, et al. 2016).
CAutoimmune/inflammatory syndrome induced by adjuvants (ASIA)Not the diagnosisASIA remains possible given the silicone implants and systemic inflammation, but it is not related to aHUS, and the direct evidence of complement‑mediated microangiopathy makes aHUS the more likely condition (Shoenfeld Y, Agmon‑Levin N. 2010; Afshar‑Kharghan, 2016).
GeneticsHeterozygous variant NM_000064.4 (C3).193A>C;
p.(Lys65Gln) in the C3 gene. Guidelines recommend genetic testing in all suspected
aHUS, but treatment should not be postponed while awaiting it, and testing is not
required to make the diagnosis (Fakhouri F, et al. 2023; Laurence J, et al. 2016).
Case · Treatment
Inhibit complement, and do it early.
The START Consensus recommends complement inhibitors as first‑line therapy
here. Expert guidance advises starting a C5 inhibitor as early as possible, ideally within
24 hours of clinical suspicion, and continuing for at least six months
(Ávila A, et al. 2023).
RavulizumabAppropriateA C5 inhibitor, authorized by the FDA for adults and children one month and older with aHUS, and by the EMA from 10 kg. Extended dosing every 4 or 8 weeks by weight reduces treatment burden (Ultomiris, FDA. 2018; Ultomiris, EMA. 2025).
EculizumabAppropriateA C5 inhibitor approved by the EMA in adults and children for aHUS; maintenance dosing every 2 weeks (Soliris, EMA. 2025).
Plasma therapyNot appropriateConsidered only where C5 inhibitors are not accessible (Ávila A, et al. 2023).
Platelet transfusionNot appropriateGenerally contraindicated here: it can worsen microvascular thrombosis (Arnold DM, et al. 2017).
Beta‑lactamsNot appropriateDirected at bacterial infection, not at complement‑mediated injury (Raina R, et al. 2019).
01Vaccinate first. Complement inhibitors increase the risk of
meningococcal infection; vaccinate at least two weeks before starting, or give prophylactic
antibiotics until two weeks after (Soliris, EMA. 2025; Ultomiris, EMA. 2025).
02Implants stay. Referral for implant removal is only
considered if ASIA is diagnosed on criteria (Shoenfeld Y, Agmon‑Levin N. 2010).