Background Severe anaemia is a major cause of morbidity and mortality in HIV-infected adults living in resource-limited countries. Comprehensive data on the aetiology are lacking but are needed to improve outcomes. Methods HIV-infected adults with severe (haemoglobin �70g/l) or very severe anaemia (haemoglobin � 50 g/l) were recruited at Queen Elizabeth Central Hospital, Blantyre, Malawi. Fifteen potential causes and associations with anaemia severity and mortality were explored. Results 199 patients were enrolled: 42.2% had very severe anaemia and 45.7% were on ART. More than two potential causes for anaemia were present in 94% of the patients including iron deficiency (55.3%), underweight (BMI<20: 49.7%), TB infection (41.2%) and unsuppressed HIV infection (viral load >1000 copies/ml) (73.9%). EBV/CMV co-infection (16.5%) was associated with very severe anaemia (OR 2.8 95% CI 1.1-6.9). Overall mortality was high (53%; 100/199) with a median time to death of 17.5 days (IQR 6-55) days. Death was associated with folate deficiency (HR 2.2; 95% CI 1.2-3.8) and end stage renal disease (HR 3.2; 95% CI 1.6-6.2).

Background: Severe anaemia is a major cause of morbidity and mortality in HIV-infected adults living in resource-limited countries. Comprehensive data on the aetiology is lacking and needed to improve outcomes. Methods:HIV-infected adults with severe (haemoglobin ≤70g/l) or very severe anaemia (haemoglobin ≤50 g/l) were recruited at Queen Elizabeth Central Hospital, Blantyre, Malawi. Fifteen potential causes of severe anaemia of anaemia and associations with anaemia severity and mortality were explored.Results: 199 patients were enrolled: 42.2% had very severe anaemia and 45.7% were on ART. Over two potential causes for anaemia were present in 94% of the patients;including iron deficiency (55.3%), underweight (BMI<20: 49.7%), TB-infection (41.2%) andunsuppressed HIV-infection (viral load >1000 copies/ml) (73.9%). EBV/CMV co-infection (16.5%) was associated with very severe anaemia (OR 2.8 95% CI 1.1-6.9). Overall mortality was high (53%; 100/199) with a median time to death of 16 days. Death was associated with folate deficiency (HR 2.2; 95% CI 1.2-3.8) and end stage renal disease (HR 3.2; 95% CI 1.6-6.2). Conclusion: Mortality among severely anaemic HIV-infected adults is strikingly high.Clinicians must be aware of the urgent need for a multifactorial approach, including starting or optimising HIV treatment; considering TB treatment, nutritional support and attention to potential renal impairment. 109HIV-infected patients with anaemia, especially in resource limiting settings, are scarce. 110Only three of our study patients had confirmed bone marrow malignancies. In contrast 111 MDS was common occurring in 27% of our patients (27, 51). 112Renal impairment was a frequent finding among our study patients and has been 113 linked to HIV disease progression, anaemia and poor outcomes in both wealthy and 114 resource limited settings (52-55). Evaluation of renal function is an important component 115 of severe anaemia treatment protocols (30, 53) since it may affect the choice of ART (52,