allopurinol and Red-Cell-Aplasia--Pure

Topics: Allopurinol; Humans; Kidney Transplantation; Middle Aged; Red-Cell Aplasia, Pure

Allopurinol potentiates azathioprine and 6-mercaptopurine (6-MP) by increasing 6-thioguanine nucleotide (6-TGN) metabolite concentrations. The outcome might also be improved by adding allopurinol in individuals who preferentially produce 6-methylmercaptopurine nucleotides (6-MMPN), rather than 6-TGN. The aim of the present study was to investigate the effect of allopurinol on concentrations of 6-MMPN and 6-TGN in individuals with a high ratio of these metabolites (>20), which is indicative of a poor thiopurine response.. Sixteen individuals were identified who were taking azathioprine or 6-MP, and were commenced on allopurinol to improve a high 6-MMPN:TGN ratio. Metabolite concentrations were compared before and after commencing allopurinol, and markers of disease control were compared.. The addition of 100-300 mg allopurinol daily and thiopurine dose reduction (17-50% of the original dose) resulted in a reduction of the median (and range) 6-MMPN concentration, from 11,643 (3,365-27,832) to 221 (55-844) pmol/8×10(8) red blood cells (RBC; P=0.0005), increased 6-TGN from 162 (125-300) to 332 (135-923) pmol/8×10(8) RBC (P=0.0005), and reduced the 6-MMPN:6-TGN ratio from 63 (12-199) to 1 (0.1-4.5) (P=0.0005). There was a significant reduction in steroid dose requirements at 12 months (P=0.04) and trends for improvement in other markers of disease control. One patient developed red cell aplasia that resolved upon stopping azathioprine and allopurinol.. In those with a high 6-MMPN:6-TGN ratio (>20), response to thiopurine treatment might be improved by the addition of allopurinol, together with a reduced thiopurine dose and close hematological monitoring.

Topics: Adult; Allopurinol; Anti-Inflammatory Agents; Azathioprine; Biotransformation; Drug Therapy, Combination; Enzyme Inhibitors; Erythrocyte Count; Female; Gastrointestinal Agents; Guanine Nucleotides; Humans; Inflammatory Bowel Diseases; Male; Mercaptopurine; Middle Aged; New Zealand; Red-Cell Aplasia, Pure; Retrospective Studies; Steroids; Thionucleotides; Time Factors; Treatment Outcome; Xanthine Oxidase

To report a rare case of combined hypersensitivity syndrome and pure red cell aplasia (PRCA) following allopurinol therapy.. A 43-year-old woman with underlying mesangioproliferative glomerulonephritis developed fever, generalized morbilliform rash, leukocytosis with marked eosinophilia, and hepatic dysfunction 3 weeks after starting allopurinol therapy (300 mg/day for 3 days followed by 200 mg/day) for hyperuricemia and arthritis. The clinical findings were judged to be a probable drug reaction according to the Naranjo probability scale. The drug-induced hypersensitivity syndrome (DHS) resolved after withdrawal of allopurinol and initiation of systemic corticosteroid therapy. However, there was progressive worsening of anemia with reticulocytopenia; PRCA was suspected. PRCA was judged to be a possible drug reaction according to the Naranjo probability scale. The patient refused blood transfusion and bone marrow biopsy. Recombinant human erythropoietin was initiated in addition to prednisolone 15 mg daily. Eleven days later (approximately 7 wk after allopurinol withdrawal), both the hemoglobin level and reticulocyte count began to rise. The patient consented to a bone marrow study at that time, which confirmed the presence of dysplasia involving only the erythroid lineage.. Allopurinol may induce DHS, aplastic anemia, and, in rare instances, PRCA. We report the first case of PRCA concurrent with allopurinol-induced DHS in a patient with chronic kidney disease. Discontinuation of allopurinol is the first step in the treatment of such cases. The slow recovery of PRCA might be partly attributed to her underlying chronic kidney disease.. To minimize serious DHS, proper indications for treatment and dosage adjustment should be closely observed when starting allopurinol therapy in patients with chronic kidney disease.

Topics: Adult; Allopurinol; Antimetabolites, Antineoplastic; Drug Eruptions; Drug Hypersensitivity; Female; Glomerulonephritis, Membranoproliferative; Humans; Hyperuricemia; Kidney Failure, Chronic; Red-Cell Aplasia, Pure

Topics: Aged; Allopurinol; Humans; Male; Red-Cell Aplasia, Pure

Several investigators have reported patients with acute pure red cell aplasia (PRCA) caused by anticonvulsants, antibiotics, or antithyroid agents. Allopurinol is known to be a causative agent of aplastic anemia, but there have been few reports of acute PRCA induced by allopurinol. We describe here a 15-year-old boy who suffered from anemia 6 weeks after initiation of allopurinol therapy; his anemia immediately improved after cessation of the drug. His bone marrow showed severe erythroid hypoplasia with a myeloid/erythroid ratio of 18.6 and low expression of glycophorin A detected on cell-surface antigen analysis. No morphological abnormalities were observed in myeloid series and megakaryocytes. The prolonged plasma iron disappearance rate and the decreased plasma iron turnover rate also indicated erythroid hypoplasia. He had been free from any infections, including parvovirus B19, before manifestation of PRCA. Taken together, these results suggest a diagnosis of acute PRCA. This side effect of allopurinol should be taken into consideration.

Topics: Acidosis; Adolescent; Allopurinol; Antimetabolites; Bone Marrow Cells; Erythrocyte Count; Hematopoietic Stem Cells; Humans; Leukocyte Count; Male; Megakaryocytes; Platelet Count; Red-Cell Aplasia, Pure; Williams Syndrome