Autoimmune haemolytic anaemia: an unusual presentation of HIV seroconversion disease
A 57-year-old man with a history of ischaemic heart disease presented with fever, macular rash and pharyngitis. He was prescribed oral penicillin and discharged. One week later, he re-presented with haemoglobinuria, jaundice and acute renal failure. He was afebrile and normotensive. Initial investigations showed haemoglobin 142 g/l, white cell count 7.8 × 109/l, platelets 180 × 109/l, alkaline phosphatase 194 U/l (reference range 30–120), alanine transaminase 117 U/l (7–56), gamma-glutamyl transferase 232 U/l (7–64), total bilirubin 150 μmol/l (<20), urea 28 mmol/l (2.5–9.6) and creatinine 283 μmol/l (40–120). Urine microscopy and chest radiograph were normal. Upper abdominal ultrasound showed mild hepatic steatosis and slight hepatosplenomegaly.
Over the next 5 days, the patient developed fatigue and dyspnoea and became severely anaemic (haemoglobin 54 g/l), with a raised lactate dehydrogenase at 5413 U/l (100–200), undetectable haptoglobin and a positive direct antiglobulin test (DAT), which revealed a mixed pattern with anti-C3b and immunoglobulin (Ig) G. Cold agglutinins and Donath-Landsteiner antibody were negative. Blood film showed spherocytosis and reticulocytopenia, and AIHA was suspected. Glucose-6-phosphate dehydrogenase (G6PD) level was 3.0 U/gHb (8.6–15.0).
HIV antibodies were reactive with high titres on multiple enzyme immunoassays. HIV western blot assay was negative initially, evolved to an indeterminate pattern and became positive 8 weeks later, consistent with HIV seroconversion. HIV-1 viral load was more than 3.5 × 106 copies/ml (log10 6.55) and initial CD4 cell count was 94 × 106/l (>400). Other serological testing revealed no evidence of acute infection with cytomegalovirus, Epstein–Barr virus, Chlamydia pneumoniae, Mycoplasma pneumoniae or parvovirus B19. Syphilis serology was consistent with previously treated or inactive infection (treponema pallidum haemagglutination detected, rapid plasma reagin not detected) and was treated with 2 weeks of intravenous benzylpenicillin.
The patient received a transfusion of 4 units red blood cells. The haemolytic anaemia was treated with oral prednisolone (1 mg/kg/day) and two doses of intravenous immunoglobulin (2 g/kg). Haemoglobin stabilized within 2 weeks of treatment and remained in the normal range. Antiretroviral treatment was commenced after stabilization with emtricitabine/tenofovir and nevirapine. Six months later, haemoglobin remained stable, HIV viral load was undetectable (<50 copies/ml) and CD4 cell count had risen to 385 × 106/l.
In this case, AIHA was most likely due to acute HIV seroconversion. The blood film revealed no characteristic changes of haemolysis associated with G6PD deficiency (blister cells). Syphilis was an unlikely cause of the patient's AIHA, as this is usually characterized by the presence of cold agglutinins  and serology was not consistent with active disease.
Positive DATs without significant haemolysis are common in HIV infection, being present in up to 43% of patients with AIDS . Patients with a positive DAT may have lower average haemoglobin levels compared to those who are DAT-negative . However, cases of overt haemolysis are rare. A literature review revealed 22 reported cases of AIHA associated with HIV infection (Table 1) [1,3–12]. Average age was 36.8 years, and 73% of cases were reported in the pre-highly-active antiretroviral therapy era. CD4 cell count was less than 200 cells/μl in seven of eight reported cases.
Available data showed the predominance of a mixed direct antiglobulin pattern in 12 of 16 (75%) patients (IgG and C3b positive), and a DAT IgG only in four of 16 (25%) patients. A mixed pattern is uncommon in non-HIV patients (IgG and C3b 7–8%, IgG only 40%) .