AZA-1

Azaspiracid-59 (AZA-59) was detected in plankton in coastal waters of the Pacific Northwest USA. Given that bivalves metabolize and transform accumulated phycotoxins, a strain of Azadinium poporum isolated from the coast of Washington State that is a known producer of AZA-59 was used in a controlled feeding experiment with mussels (Mytilus edulis) to assess AZA-59 accumulation rates and transformation into shellfish metabolites. Mussels started feeding immediately after the addition of A. poporum. Mussels were generally healthy during the entire experimental exposure of 18 days with prevailingly high rates of clearance (ca 100 mL per mussel and hour) and ingestion. Mussel were extracted after different exposure times and were analyzed by liquid chromatography coupled with low- and high-resolution mass spectrometry. In the course of the experiment a number of putative AZA-59 metabolites were detected including hydroxyl and carboxy analogs that corresponded with previously reported mussel metabolites of AZA-1. A significant formation of 3-OH fatty acid acyl esters relative to free AZAs was observed through the time course of the study, with numerous fatty acid ester variants of AZA-59 confirmed. These results illustrate the potential for metabolism of AZA59 in shellfish and provide important information for local AZA monitoring and toxicity testing along the Northern Pacific US coast.

To analyse the effectiveness, safety and steroid-sparing effect of AZA and MTX as induction of remission and maintenance treatment in eosinophilic granulomatosis with polyangiitis.

We retrospectively collected data from 57 patients divided into four groups according to treatment: MTX/AZA as first-line agents (MTX1/AZA1) in non-severe disease or as second-line maintenance therapy (MTX2/AZA2) in severe disease previously treated with CYC/rituximab. During the first 5 years of treatment with AZA/MTX we compared the groups according to: remission rate [defined as R1: BVAS = 0; R2: BVAS = 0 with prednisone ≤5 mg/day; R3 (MIRRA definition): BVAS = 0 with prednisone ≤3.75 mg/day], persistence on therapy, cumulative glucocorticoid (GC) dose, relapse and adverse events (AEs).

There were no significant differences in remission rates (R1) in each group (63% in MTX1 vs 75% in AZA1, P = 0.53; 91% in MTX2 vs 71% in AZA2, P = 0.23). MTX1 allowed R2 more frequently in the first 6 months compared with AZA1 (54% vs 12%, P = 0.04); no patients receiving AZA1 achieved R3 up to the first 18 months (vs 35% in MTX1, P = 0.07). The cumulative GC dose was lower for MTX2 vs AZA2 (6 g vs 10.7 g at 5 years, P = 0.03). MTX caused more AEs compared with AZA (66% vs 30%, P = 0.004), without affecting the suspension rate. No differences emerged in time-to-first relapse, although fewer patients treated with AZA2 had asthma/ENT relapses (23% vs 64%, P = 0.04).

A significant proportion of patients achieved remission with both MTX and AZA. MTX1 had an earlier remission on a lower GC dose but MTX2 had a better steroid-sparing effect.