[Use of PCR for diagnosing cat-scratch disease].

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

Material and methods: 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.

Results: 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.

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