1
The prevalence of HLA-B*5701 and of suspected reactions prior to screening were in accordance to the described for the European population Most suspected ABC-HS reactions were either rash or fever and none required hospitalization We were able to exclude an association between abacavir/HLA-B*5701 and the presented reaction in 2 patients The relevance of patch tests in these patients could not be fully evaluated due to missing data No ABC-HS occurred since January 2008, when HLA-B*5701 screening was implemented Natacha Santos 1 , Carmela Pinheiro 2 , Fabrícia Carolino 1 , Ana Sofia Faustino 2 , Pedro Soares 3 , António Sarmento 2 , Josefina Rodrigues Cernadas 1 1 Immunoallergology Department, Centro Hospitalar Sao Joao, E.P.E., Porto, Portugal. 2 Infecciology Department, Centro Hospitalar Sao Joao, E.P.E., Porto, Portugal. 3 Pharmacy Department , Centro Hospitalar Sao Joao, E.P.E., Porto, Portugal Abacavir is an antiretroviral drug used as first line treatment for HIV infection. Of treated patients, 5-8% develop an abacavir-associated hypersensitivity syndrome (ABC-HS) in the first 6 weeks, which can be life-threatening. ABC-HS has been strongly associated with the presence of the HLA- B*5701 allele. Screening for this allele is recommended for all patients prior to beginning therapy with abacavir since it virtually eliminates all immunologically confirmed ABC-HS. Aims: • To determine the prevalence of HLA-B*5701 in the adult HIV population followed in our hospital • To characterize and confirm suspected ABC-HS Clinical data on patients under abacavir treatment since January 2006 was analyzed to search for symptoms of ABC-HS. HLA-B*5701 screening was performed by real time PCR in all patients since January 2008 and those with positive HLA-B*5701 began HIV treatment with an alternative drug. Reactions of suspected ABC-HS were characterized. HLA-B*5701 and patch tests (1% and 10% abacavir in petrolatum) with readings at 48 hours, were performed in patients with suspected ABC-HS without previous testing. In relation to this presentation, I declare that there are no conflicts of interest January 2008 to December 2012 573 patients screened 35 (6.1%) HLA-B*5701 positive No suspected ABC-HS January 2006 to December 2007 186 patients began abacavir 7 (4.3%) with suspected ABC-HS Gender Age at reaction (years) Median=45 Time of onset (days) Median=7 Clinical manifestations HLA-B*5701 Patch tests male 35 3 Liver enzymes elevation Negative Negative female 36 7 Non pruritic rash and myalgia Positive n.p.§ male 63 1 Sensation of dyspnea and throat swelling n.p.¤ n.p.¤ male 45 13 Fever, pruritus, malaise and liver enzymes elevation Positive Positive male 59 4 Fever, rash, myalgia and liver enzymes elevation n.p.¥ Positive female 51 10 Fever and malaise Negative Negative male 27 12 Pruritic rash in the trunk Positive Negative Figures 1 and 2. Abacavir 1% and 10% patch tests positive for the 10% concentration n.p. not performed. § unable to commute to hospital to perform patch tests. ¤ unreachable. ¥ HLA-B*5701 testing ongoing Data unavailable in 23 patients Two patients were treated with oral corticosteroids. None required hospitalization.
