We read with great interest the article by Feletar et al.¹ We were surprised by their findings of only a modest response to infliximab treatment in patients with treatment refractory psoriatic arthritis (PsA), as this seems to be in contrast with our observations.

Since 2001 nine patients with refractory PsA according to American College of Rheumatology criteria have been treated with infliximab at our division. All patients had active joint disease with a tender joint count (TJC) and a swollen joint count (SJC) of at least 6, with the exception of one patient (patient 3), whose cervical spine was affected. Quantitative assessment of skin involvement was not available. Table 1 shows further demographic data.

Seven patients received infliximab for more than 52 weeks, and five of those for more than 78 weeks. Clinical assessment, including TJC and SJC, performed by experienced rheumatologists, and laboratory tests (haematology, biochemistry, antinuclear antibodies (ANA), including subsets) was made routinely at each visit (fig 1). During the treatment period toxicity occurred on three occasions, including one labial herpes infection (patient 4), one leucopenia of 2.6×10⁹/l (patient 3), which led to the discontinuation of methotrexate, …