Giant cell arteritis and polymyalgia rheumatica after influenza vaccination: comparing different experiences

We read with interest the letter by Wada et al. titled “Giant cell arteritis with polymyalgia rheumatica associated with influenza vaccination”.1 The authors reported the case of a previously healthy 70-year-old woman vaccinated against influenza virus a day before the onset of severe headache, pain in the bilateral shoulders and upper arms, and jaw claudication. The patient’s symptoms and laboratory results fulfilled both the 1990 American College of Rheumatology (ACR) and Bird’s criteria for giant cell arteritis (GCA) and polymyalgia rheumatica (PMR), respectively. Influenza vaccination is a widely accepted recommendation in high-risk individuals and it can be associated with minor and transient side-effects, whereas systemic complications such as rheumatic disorders or vasculitis are rare.2 Recently, we reported the analysis of our case series of 10 previously healthy subjects who developed GCA and/or PMR following influenza vaccination and for comparison we conducted a systematic published work survey of reports on GCA and PMR occurring after influenza vaccination.3 In our case series two out of 10 patients developed GCA/PMR within 3 months of influenza vaccine, six patients developed isolated GCA and two patients developed isolated PMR. The GCA diagnosis was established according the ACR criteria and PMR according to the Healey criteria. Our published work survey yielded four isolated cases of GCA following influenza vaccination: over the cases already cited by Wada et al., we found that in 2008 Pou et al.4 reported another case of isolated GCA 1 week after influenza vaccination had been administrated to a 74-year-old patient. Regarding the coexistence of GCA and PMR following vaccination, in 2001 Saadoun et al.5 reported the case of a 64-year-old woman with a previous diagnosis of PMR in clinical remission after steroid therapy, who developed headache, joint claudication and cough 3 days after influenza vaccination, in absence of polymyalgic symptoms or visual abnormalities. High-dose steroid therapy was administrated and the symptoms disappeared, achieving disease control even when the steroid was tapered. Also, an interesting point underlined by Wada et al. concerns the previous influenza vaccination the patient had undergone 2 years earlier, without any complications. In our case series, a patient diagnosed with PMR following influenza vaccination, in clinical remission after steroid therapy, experienced a relapse of her disease 2 years later, when she underwent revaccination with the seasonal influenza vaccine. As the viral components of vaccines vary from year to year, while adjuvants have been used for decades in a restricted number, we correlated our observation with the new “ASIA syndrome” (i.e. autoimmune/inflammatory syndrome induced by adjuvants) recently described by Shoenfeld and Agmon-Levin and including post-vaccination phenomena.6 We are typing our cases for human leukocyte antigen to detect the genetic susceptibility and we suggest this test should be performed in all similar cases for a possible multicentric study. Moreover, we recommend a systematic research of previous vaccination within 1–6 months in patients with recent onset of GCA/PMR and a strict follow up of all vaccinated subjects carrying already known autoimmunity markers.