Isoniazid-induced Pure Red Cell Aplasia in a Patient with Sarcoidosis: A Patient Summary and Review of the Literature

Adult pure red cell aplasia at Universitas Academic Hospital, Bloemfontein, South Africa: A 9-year review

Background. Pure red cell aplasia (PRCA) is characterised by severe normochromic, normocytic anaemia and partial or complete absence of reticulocytes from the peripheral blood. With bone marrow of normal cellularity, an almost complete absence of erythroblasts but preservation of other cell lines is observed. It may be congenital or acquired, with the latter presenting as a primary haematological disorder or secondary to various contributing factors. Management focuses on treatment of the underlying cause and supportive transfusions. Occasionally, immunosuppression or intravenous immunoglobulin (IVIG) is required.Objectives. To describe the clinical characteristics, treatment and outcomes of adult patients diagnosed with PRCA at Universitas Academic Hospital (UAH) in Bloemfontein, South Africa, from 2010 to 2018.Methods. A retrospective descriptive file review was performed. All adult patients diagnosed with PRCA and treated in the Division of Clinical Haematology at UAH during the study period were included. Variables recorded included demographic information, clinical details of the PRCA diagnosis, classification of the PRCA, HIV and parvovirus B19 test results, results of special investigations, medical and drug history, treatment and response to treatment.Results. Twenty-seven patients’ files were included, with a female predominance (n=22; 81.5%). The median age at diagnosis was 35 years (range 20 - 62). The median number of days from onset of symptoms to date of diagnosis was 61 days (range 27 - 114). Approximately half (n=13; 48.2%) of the patients presented with a haemoglobin concentration of 1 - 3 g/dL. Most patients (n=26; 96.3%) were infected with HIV, with 76.9% (n=20) having a suppressed viral load. Parvovirus B19 infection accounted for 44.4% of cases (n=12), and all these patients were HIV positive. Lamivudine was a probable cause of PRCA in 18.5% of cases, although the true causal relationship was uncertain. Corticosteroids and IVIG were first-line therapy in 44.4% (n=12) and 37.0% (n=10) of cases, respectively. Thirteen patients (48.2%) achieved a complete response and 7 (25.9%) a partial response, while 2 (7.4%) showed no response, with continued transfusion dependence.Conclusion. In this population, women were disproportionately affected by PRCA. HIV was the single most important cause of acquired PRCA, which was independent of virological control. Parvovirus B19 and drugs were also important causes of acquired PRCA and played a critical part in the evaluation and work-up of PRCA. Nearly half of the patients achieved a complete response to therapy, which was sustained over 24 months.

Isoniazid-induced pure red cell aplasia

The pure red cell aplasia (PRCA) is an uncommon side effect of isoniazid. We describe a 28-year-old man who developed a severe anaemia caused by PRCA. The patient received antituberculous therapy including isoniazid for his pulmonary tuberculosis. On discontinuation of isoniazid, the anaemia recovered promptly. PRCA should be considered in case of unexplained anaemia during isoniazid treatment.