We are sincerely grateful for the interest shown by Dr. Suárez-Díaz and Dr. Caminal-Montero in the SER recommendations for the prevention of infection in patients with systemic autoimmune rheumatic diseases, as well the interesting questions they raise in their letter about the same.

Respecting the first question, about the dose of trimethoprim–sulfamethoxazole (TMP/SMX) for prophylaxis of Pneumocystis jirovecii, drawing up the final recommendation involved a long discussion within the multidisciplinary panel. This was because the most widely used dose in rheumatology is the high dose (160mg TMP and 800mg SMX), administered 3 days a week. Nevertheless, as we argue in the document, and given that the recommendations are based on the available evidence, the lower dose (i.e., 400mg sulfamethoxazole and 80mg trimethoprim) administered daily is considered to be better supported in the scientific literature, and it may also give rise to a higher probability of adherence, as the doses are not intermittent. Another factor that was taken into consideration for the final decision on the dose was precisely the availability in Spain of the 400mg/80mg, format, while no 200mg/40mg, format was available here when the recommendations were prepared.1 We do not believe that our recommendation may lead to confusion, as the authors of the letter suggest, as the discussion of the same clearly indicates that the high dose (160mg TMP and 800mg SMX), should always be administered 3 times a week. In any case, the systematic review on which the recommendation was based recognised alternative dosage regimes which are effective and safe.2 As there are several options, it is of course necessary to be especially careful when prescribing and offering information to the patient. Another aspect which should be clarified solely affects the wording of the recommendation, and it consists of the order in which doses are mentioned when given in combination. Although it is true that trimethoprim is mentioned prior to sulfamethoxazole in the recommendation, the dose mentions 400mg/80mg. It may have been desirable to mention the doses in reverse order, as 80mg/400mg. In any case, it is also true that several generic formulations available in our country show sulfamethoxazole first.

With respect to the second, very relevant question asked by the authors of the letter, the fact that no recommendations for tuberculosis are included is due to a question of economy of resources. According to the normalized procedures of the Spanish Society of Rheumatology, the documents of recommendations it produces are limited in scope. This is because they only aim to cover specific areas of patient management, and therefore only answer a restricted number of research questions. Infection by tuberculosis is excluded because the panel of experts who prepared the document understood that it would be of less interest to include recommendations for the treatment of latent tuberculosis. This is because no specific peculiarities for specific autoimmune rheumatic systemic diseases could be foreseen here that would have justified the effort and replaced another research question. As occurs in the prevention of other infections, the panel decided to mention the need for this, referring to generic high-quality documents which are already available and have recently been updated.3