This strange string of events, all happening in that order (HIV+Tapeworm+Cancer=Death?) has led to the death of a 41 year old Colombian man. This medical event has baffled physicians and scientists alike where a link between host and parasite eventually led to cancer. The patient was an HIV positive individual who failed to take the medication required to level out his CD4 count, or white blood cell count. As a result his levels were dangerously low and his body was left unprotected against foreign invaders. This led him to be infected with the most common tapeworm known as Hymenolepis nana. All seems somewhat normal thus far, right?
The patient came in complaining of a cough, weight loss, fatigue, and presented with a high fever. During this visit the patient was given a CT scan which showed that his lungs had tumors throughout ranging from 0.4 to 4.4 centimeters, his liver and adrenal gland also showed nodules. They then took biopsies of the effected organs and analyzed them. This is where the strange occurrence gets good.
Histological analysis showed that the cells were cancerous no doubt, the cells were crowded, in disarray, and all looked the same. However, they were extremely tiny, about ten times smaller than what would be considered human. After much confusion DNA analysis showed that the tumor cells were made of H. nana DNA. Essentially, the tapeworm had given him cancer. Unfortunately these findings came too late, and the man died 72 hours later.
The occurrence has never been shown, of a connection of a malignant invertebrate cell line crossing over with a human cell line. Cancer cells naturally circulate in some animals, however it is not “really” transmissible between humans. Due to the patients weakened immune system the parasitic cells were able to grow uncontrollably which let to the accumulation of the cancer-causing mutations. Due to the abundance of both HIV and the H. nana throughout the world it is likely this has happened before but has been misdiagnosed as strictly human cancer. This host-parasite newly discovered interaction should lead to new avenues exploring the connection between infection and cancer.
Sources:
http://www.iflscience.com/health-and-medicine/parasitic-worms-cancer-cells-caused-tumors-hiv-positive-man
Original Journal Article:
Muehlenbachs, A, et al. (2015). Malignant Transformation of Hymenolepis nana in a Human
Host. The New England Journal of Medicine. Retrieved from
This is very interesting and a little unsettling. I wonder if we will see more cases of this down the line or if this was just some rare instance. I am curious as to whether this situation could occur in a nonimmunocompromised individual or only in someone with HIV. Hopefully more research is done to determine the physiological mechanism of this strange occurrence.
ReplyDeleteThis is very interesting and a little unsettling. I wonder if we will see more cases of this down the line or if this was just some rare instance. I am curious as to whether this situation could occur in a nonimmunocompromised individual or only in someone with HIV. Hopefully more research is done to determine the physiological mechanism of this strange occurrence.
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