[Use of PCR for diagnosing cat-scratch disease]

The diagnosis of Bartonella henselae by polymerase chain reaction (PCR) in lymph nodes removed in 10 patients with serologically confirmed evidence cat-scratch disease.

The 2015-2018 group consisted of 10 patients with serologically confirmed cat-scratch disease, all of them having positive IgG antibodies and 6 patients also positive IgM antibodies against B. henselae. The group included 4 men and 6 women, 7 children and 3 adults, aged 5-52 years. Eleven lymph nodes obtained from the 10 patients were formalin-fixed paraffin-embedded. Variants of granulomatous inflammation were found in 9 patients; a 13-year-old boy had Hodgkin's lymphoma. DNA isolation was performed with cobas® DNA Sample Preparation Kit (Roche). DNA of Bartonella spp. was detected by real-time PCR with BactoReal® Kit Bartonella spp. (Ingenetix) detecting the gltA gene specific for the genus Bartonella.

Four of the 10 patients tested positive or borderline positive for Bartonella when their histological material was analyzed by PCR. One patient with 2 lymph nodes examined showed a positive result for only 1 lymph node. One adult male had a positive result; three children showed borderline positive results. Of those, two patients had suppurative granulomatous and the other 2 patients had necrotizing suppurative granulomatous inflammation as histological findings. All 4 patients had positive IgM antibodies against B. henselae. The boy with lymphoma had a negative PCR result.

Serological tests combined with histological examination of lymph nodes and PCR may improve the diagnosis of cat- scratch disease.