When we result a Pap test as unsatisfactory due to lubricant contamination, it is easy to assume the provider contaminated the sample with speculum gel. However, sometimes it's not the provider's use of lubricant, but the patient's use of certain products that causes the unsatisfactory result. In a recent study, I assessed the potential of Replens, KY Warming Liquid and Monistat 7 to interfere with ThinPrep Pap tests.¹

The results showed that Replens had a drastic effect on cellularity at even 20 uL. Just to put that into perspective, one drop of water is typically considered to be around 50 uL. In other words, less than a drop of Replens placed into a ThinPrep vial rendered the specimen unsatisfactory for evaluation.

Replens advertises that it lasts up to 3 days. It uses bioadhesive molecules such as carbomers or carbopol polymers to achieve this. My hypothesis is that these molecules stick to the semipermeable membrane of the ThinPrep filter during processing.

This quickly clogs the device so that not enough cells are collected and transferred to the slide. In fact, a good clue that lubricant is the cause of an unsatisfactory Pap test is that the vial is still full of liquid. If the unsatisfactory result was caused by low cellularity, the vial would be almost completely empty due to the processor sucking out all the fluid in an attempt to collect enough cells. In addition, when looking at the fluid in a vial that is contaminated with lubricant containing bioadhesive molecules, you will typically notice flecks of precipitate due to the cells sticking together.

Monostat 7 is a common yeast medication. It also interfered with ThinPrep Pap tests, but the effect was not as drastic as Replens. It reduced the cellularity incrementally as the volume of contamination increased (20 uL = 69 percent reduction, 100 uL = 83 percent reduction, 500 uL = unsatisfactory for evaluation). Other types of Monostat exist that advertise the need for fewer applications (e.g., Monostat 3 and Monostat 1). Monostat 1 contains bioadhesive molecules, which allow it to last up to 7 days. Therefore, I would suspect it of producing the same effect as Replens.

KY warming liquid had no effect on the cellularity of the ThinPrep Pap test at any volume of contamination in this in-vitro study. Warming and/or tingling liquids and gels often create sensations by irritating the epithelium and increasing mucus production.² Excessive mucus may cause sub-optimal or unsatisfactory Pap test. An in-vivo study would need to be conducted to test this possibility however.

This study showed that the potential exists for some over-the-counter products to interfere with ThinPrep Pap tests and cause unsatisfactory results. As they can be retained on the epithelium for several days, there is a high probability for their transference to the ThinPrep vial during sampling. Therefore, when educating providers about unsatisfactory Pap tests, it may be prudent to have them ask their patients to avoid use of personal lubricants and vaginal medications for at least a week before their scheduled exam.

Tim D. Feit is assistant operations manager, chief compliance officer and IS coordinator, Dane County Cytology Center, Inc., Madison, WI.

References

1. Feit TD, Mowry D. Interference potential of personal lubricants and vaginal medications on ThinPrep Pap tests. J Am Board Fam Med 2011;24:181-186.
2. Adriaens E, Remon JP. Mucosal irritation potential of personal lubricants relates to product osmolality as detected by the slug mucosal irritation assay. Sex Transm Dis 2008;35:512-16.