Two cases of differentiation syndrome with ocular manifestations in patients with acute promyelocytic leukaemia treated with all-trans retinoic acid and arsenic trioxide

Purpose

To describe two cases of differentiation syndrome presenting with ocular manifestations including bilateral chorioretinopathy in patients with acute promyelocytic leukaemia treated with all-trans retinoic acid and arsenic trioxide differentiation therapy.

Observations

This observational case series identifies two patients at a single tertiary institution diagnosed with differentiation syndrome with associated ophthalmic involvement. Both patients reported bilateral reduction in visual acuity at days fourteen and ten respectively following initiation of differentiation therapy in addition to developing other systemic manifestations of differentiation syndrome. Both patients received the same chemotherapeutic regimen including both all-trans retinoic acid and arsenic trioxide as well as ten days of routine differentiation syndrome prophylaxis with oral prednisolone. Case 1 presented with bilateral pale yellow sub-retinal lesions concentrated at the posterior poles with ocular coherence tomography (OCT) evidence of bilateral multifocal areas of focal RPE elevation and adhesion to the thickened outer retina with interspersed sub-retinal fluid. Fluorescein angiography revealed areas of early hyperflouresence corresponding to the yellow chorioretinal lesions with late diffuse leakage of fluid into the subretinal space. Case 2 presented with a similar characteristic retinal findings on fundoscopy and optical coherence tomography. Both patients experienced rapid improvement in the visual symptoms and marked resolution of the sub-retinal fluid within seven to fourteen days of onset with excellent long-term visual outcome. Both patients achieved molecular remission after induction and received standard consolidation and maintenance therapy without visual disturbance.

Conclusion and importance

Ocular manifestations of differentiation syndrome have been only recently recognised. We present a case series of two patients with differentiation syndrome with ocular involvement. Common to both presentations was the presence of bilateral reduction in visual acuity with multifocal serous retinal detachment secondary to chorioretinopathy. The visual outcome from both presentations was excellent with rapid normalisation of visual acuity and resolution of the sub-retinal fluid with only the first case having their differentiation therapy temporarily withheld during the acute phase of illness.

Glycoprotein IIb/IIIa receptor therapy in percutaneous coronary intervention and non-ST-segment elevation acute coronary syndromes. Estimating the economic implications

In addition to efficacy and safety, cost is an important determinant of the use of glycoprotein IIb/IIIa (GPIIb/IIIa) therapy in patients with acute coronary syndromes (ACS) or undergoing percutaneous coronary intervention (PCI). In PCI, the average procurement cost of GPIIb/IIIa therapy ranges from $US400 to $US1500 (1999 values) per patient treated, depending on agent, dose and duration of infusion. Prospective economic substudies with abciximab and tirofiban have demonstrated subsequent cost savings that partially offset the procurement costs of the agents. The drug procurement costs per death or myocardial infarction (MI) prevented in PCI appear to vary from $US10,500 to $US37,000, depending on the agent. Abciximab has been proven to provide a survival benefit in the setting of PCI, including coronary stenting. Analyses of abciximab use yield cost-effectiveness ratios of $US2875 to $US14,765 per life-year or quality-adjusted life-year saved, which compares favourably with most widely accepted therapies. In non-ST-segment elevation ACS, drug procurement costs range from $US700 to $US1700 per patient treated, also depending on agent, dose and duration of infusion. Evidence of cost offsets from changes in subsequent resource utilisation are limited and seem contingent upon a conservative risk-stratification approach. Drug procurement costs have been calculated as $US32,000 to $US82,000 per death or MI prevented in the ACS trials. Cost-effectiveness ratios of $US16,000 per life-year saved for the US and Western European cohorts in the Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy (PURSUIT) trial are favourable. If these analyses prove correct, the cost effectiveness of GPIIb/IIIa receptor therapy for patients with non-ST-segment elevation ACS will also compare favourably with other widely accepted therapies in industrialised countries. More clinical and economic data are necessary to allow better selection of specific patients who will receive the most benefit from GPIIb/IIIa therapy in healthcare systems with limited resources.

Economic issues in glycoprotein IIb/IIIa receptor therapy

Efficacy, safety, and cost will determine the use of glycoprotein IIb/IIIa therapy in patients with acute coronary syndromes or those patients undergoing percutaneous coronary intervention (PCI). Prospective randomized studies with abciximab, eptifibatide, and tirofiban have demonstrated the superior efficacy and relative safety of IIb/IIIa therapy in these 2 broad patient groups. In medical practice, we by necessity make decisions to administer or withhold therapies based on implicit concepts of cost-effectiveness and efficacy and safety. We herein review available economic data on IIb/IIIa therapy to assist in this decision-making process. The procurement costs of the IIb/IIIa receptor antagonists vary considerably for both acute coronary syndrome and patients undergoing PCI. In PCI, these procurement costs range from $436 to $1407 per patient treated with commonly used regimens. Economic substudies of PCI trials with abciximab and tirofiban demonstrate medical cost savings that partially offset drug procurement costs. The number of dollars spent on IIb/IIIa agents per death or myocardial infarction prevented in patients undergoing PCI ranges from $13,000 to $37,000. Abciximab has cost-effectiveness ratios of $4000 to $7000 per life-year saved in patients undergoing PCI. The incremental cost-effectiveness of IIb/IIIa blockade in the setting of planned stenting is unknown. In patients with acute coronary syndrome, procurement costs range from $1050 to $1548 per patient treated. Expenditures per death or myocardial infarction prevented in patients with acute coronary syndrome range from $32,000 to $82, 000. Inadequate direct cost data exist to calculate cost effectiveness ratios for this group, but only high-risk patients will likely have cost-effectiveness ratios that most Western health-care systems can afford.

Synthesis of 5-amino-1-(5-deoxy-beta-D-ribofuranosyl)imidazole-4-carboxamide and related 5'-deoxyimidazole ribonucleosides

5-Amino-1-(beta-D-ribofuranosyl)imidazole-4-carboxamide (1, AICA ribonucleoside) was converted in two steps to 5-amino-1-(5-deoxy-5-iodo-2,3-O-isopropylidene-beta-D-ribofuranosyl)imidazole-4-carboxamide (3) which was hydrogenated in the presence of Pd/C to yield 5-amino-1-(5-deoxy-2,3-O-isopropylidene-beta-D-ribofuranosyl)imidazole-4-carboxamide (4). The dehydration of 4 yielded 5-amino-1-(5-deoxy-2,3-O-isopropylidene-beta-D-ribofuranosyl)imidazole-4-carbonitrile (7). The compounds 3, 4, and 7 were deblocked with formic acid to furnish 5-amino-1-(5-deoxy-5-iodo-beta-D-ribofuranosyl)imidazole-4-carboxamide (6). 5-amino-1-(5-deoxy-beta-D-ribofuranosyl)imidazole-4-carboxamide (5), and 5-amino-1-(5-deoxy-beta-D-ribofuranosyl)imidazole-4-carbonitrile (8), respectively. Compound 8 was acetylated and then deaminated to give 1-(2,3-di-O-acetyl-5-deoxy-beta-D-ribofuranosyl)imidazole-4-carbonitrile (11). The compounds 8 and 11 were converted into 5-amino-1-(5-deoxy-beta-D-ribofuranosyl)imidazole-4-thiocarboxamide (9) and 1-(5-deoxy-beta-D-ribofuranosyl)imidazole-4-thiocarboxamide (12), respectively. The synthesis of 1-(5-deoxy-beta-D-ribofuranosyl)imidazole-4-carboxamide (13) was achieved for the first time by the treatment of 11 with hydrogen peroxide in the presence of ammonium hydroxide. The compounds were tested for antibacterial, antifungal, and antiviral activity, with 5 and 6 significantly inhibitory to Staphylococcus aureus.