Increased translocation frequency of chromosomes 7, 11 and 14 in lymphocytes from patients with neurocysticercosis

Neurocysticercosis (NCC) has been associated with a high frequency of DNA d amage in human circulating lymphocytes and more recently with the developme nt of hematological malignancies. Chronic inflammation, a common feature of helminthic infections, has been proposed to play a key role in carcinogene sis induced by parasites. However, this mechanism is more likely to occur d uring local tumorigenesis rather than in systemic neoplasia such as that re ported for patients with NCC. As an alternative, constant antigen stimulati on, which is a feature of chronic NCC, may increase the frequency of aberra tions in chromosomes that harbor regions constantly rearranged during T and B lymphocyte maturation, e.g. chromosomes 7 and 14. Therefore, in this stu dy we determined the frequencies of aberrations in chromosomes 7, 11 and 14 in lymphocytes from 10 NCC patients and 10 controls and compared them with the frequency observed in chromosomes 1, 2 and 4 in the same cell samples. Chromosome aberrations were analyzed using a chromosome painting technique . Although the genome painted by probes for chromosomes 1, 2 and 4 was almo st twice as large as that painted by probes for chromosome 7, 11 and 14, tr anslocations involving the later (median 7.6 per 1000 metaphases) were more frequent than those occurring in chromosomes 1, 2 and 4 (median 2.5 per 10 00 metaphases, P = 0.002). These results suggest that persistent antigen st imulation can cause chromosome instability in lymphocytes from patients wit h NCC and should be considered as an additional mechanism whereby parasites may induce cancer.