Table 2.

Diagnostic workup in front of a patient with suspicion of thrombotic microangiopathy (TMA) [3].

(1) To establish the suspicion of TMA

(i) Thrombocytopenia (<150 × 109/l or >25% of decrease)

(ii) Signs of microangiopathic hemolysis

(iii) Anemia (±increase in mean corpuscular volume)

(iv) Reticulocyte count raised

(v) Lactate dehydrogenase (LDH) increased with haptoglobin decreased

(vi) Direct Coomb's test negative

(vii) Blood smear searching schistocytes

(2) To look for organ involvement

(i) Neurological: confusion, headache, seizures, encephalopathy, and focal deficits

(ii) Renal: ARF, arterial hypertension, proteinuria, and hematuria

(iii) Cardiac: cardiac failure, hypotension, and ischemic cardiopathy

(iv) Pulmonary: ARDS and respiratory insufficiency

(v) Gastrointestinal: abdominal pain, intestinal angina, diarrhea, and vomiting

(vi) Hematological (thrombocytopenia): epistaxis, hemoptysis, menorrhagia, retinal hemorrhage, gastrointestinal bleeding, and petechiae

(3) To confirm organ involvement

(i) Blood analysis including renal function, cellular blood count, LDH, liver and pancreatic enzymes, creatin kinase, and troponin I

(ii) Renal biopsy: to confirm glomerular microthrombosis

(iii) CT/MRI brain: to determine neurological involvement

(iv) Electrocardiogram/echocardiogram: to document or monitor cardiac damage

(v) Chest radiograph/CT: to document lung involvement

(vi) Echography/CT: to document hepatic/pancreatic/intestinal involvement

(vii) Fundoscopic examination: to document retinal vessel involvement

(4) To investigate the etiology

(i) ADAMTS 13 activity: <5–10% (TTP)

(ii) If gastroenteritis (bloody diarrhea): Shiga toxin/STEC: positive (HUS)

(iii) If ADAMTS13 > 10%: secondary or associated TMA

(iv) Fundoscopic examination (malignant hypertension)

(v) Immunologic profile: ANA, ANCA, and aPL (autoimmune diseases)

(vi) Pregnancy test (pregnancy-related)

(vii) CT thoracoabdominal or PET: cancer-associated

(viii) Clinical history looking for drugs/heparin and anti-PF4 antibodies (HIT)

(ix) Complement studies: FH, FB, FI, anti-FH antibodies, and genetic study (aHUS)

aHUS: atypical HUS, ANA: anti-nuclear antibodies, ANCA: anti-neutrophil cytoplasmic antibodies, aPL: anti-phospholipid antibodies, CT: computed tomography, HIT: heparin-induced thrombocytopenia; HUS: hemolytic uremic syndrome, PET: positron emission tomography, STEC: Shiga toxin Escherichia coli, TTP: thrombotic thrombocytopenic purpura.