Study of possible association of chronic typhoid infection in patients with chronic leukemia

Abstract

Objective: The study of the possible association of chronic typhoid infection in patients with chronic leukemia. Materials and Methods: A total of twenty patients with chronic myeloid leukemia (CML) either newly diagnosed or follow-up patients with or without chemotherapy in the chronic phase of the disease and ten patients with chronic lymphocytic leukemia had comprised of the study. Bone marrow (BM) samples of 20 controls had been taken from the Orthopedic department during surgery. BM was aspirated from iliac crest under aseptic precautions and BM biopsy was done, samples were stored at 4°C. BM samples were subjected for polymerase chain reaction (PCR) analysis for Salmonella typhi. Blood and stool sample from the patients were also collected for Salmonella culture, serological assays. BM samples from control had been taken during orthopedic surgery. Results: S. typhi infection, the comparison between CML patients and healthy controls had been made based on the PCR results. The result is significant with 40% positivity for S. typhi PCR in CML patients when compared to 20% positivity in healthy controls with P = 0.028 which is statistically significant. In patients with chronic lymphocytic leukemia, 10% of BM samples showed positivity for S. typhi by PCR targeting flagellin gene-specific nucleotide sequences and 10% of controls showed positivity for S. typhi and was statistically insignificant (P = 1.00). Conclusion: The early incidence of the disease in tropical country like India favors the hypothesis of chronic inflammation in the early process of leukemogenesis. The result of the study also questions whether attenuated bacteria can be used safely for vaccination and delivering therapeutic agents. Moreover, in a tropical country like India where S. typhi infection is endemic, the infection with the same can be taken as a marker of chronic inflammation and its role in the etiopathogenesis of CML remains to be understood.