FIELD OF THE INVENTIONThe present invention relates generally to the field of screening and health control. More specifically the invention relates to a novel sampling system and associated methods suitable, for example, in testing to detect virus-associated cervical cancer, microbial infections and pathological changes.
BACKGROUND OF THE INVENTIONCervical cancer is the second most common form of cancer in women world-wide. Invasive cervical carcinoma develops by progression of less severe epithelial changes, known as dysplacia and cervical intraepithelial neoplacia (CIN I-II-III), into cervical carcinomas in situ (CIS).
Using vaginal aspirates (Pap smears), the epithelial changes can be detected and classified by common cytological methods. It is particularly important to notice that invasive cervical carcinoma is preceded by its dysplastic precursor lesions, which can be present for months or years before cervical carcinoma develops. Furthermore, progression to carcinoma can effectively be stopped by a simple operation (conization) if the precursor lesions are detected.
Many developed countries have experienced up to a 50% reduction in the incidence of and mortality from invasive cervical carcinoma after the introduction of organized screening programs. Despite this fact, about 500,000 women in the world are struck by cervical cancer each year. In the U.S., close to 5,000 women die each year from this disease. This number would drop further if more women were tested on a regular basis.
Of those who die of cervical cancer, 50% have not had a Pap test done in 5 or more years. Indeed, those women who do not participate in the gynecological health control and those who show false negative cytology are the highest risk groups for cervical cancer. The efficacy and reliability of the sampling method and the sample's analysis are therefore primary issues. This involves, in the first place, reaching those women who do not now participate in the gynecological screening by providing a simple and reliable device for sampling, and secondly, to increase the discriminating efficacy of the analytical methods to diagnose infections, precancerous lesions or cancerous lesions.
Association between papillomavirus (HPV) infection and cervical carcinoma was postulated in the 1970's. The International Biological Study on Cervical Cancer reported a world-wide prevalence of infection with HPV of 93% in women with invasive cervical cancer. In addition, thesubtypes HPV16 and HPV18 are the most significant risk factors in its aetiology. HPV infection is also an important risk factor for progression of CIN.
Recent studies with improved methods of polymerase chain reaction (PCR) imply an overall HPV prevalence of almost 100% and that the PCR results correlate with the histological findings. These results reinforce the rational for HPV testing in combination with, or even instead of, cytology in population-based screening programs.
Determination of squamous intraepithelial lesions, or cervical dysplacia, is commonly used as an indication of progression to cervical cancer. Alternatively, the presence of HPV nucleic acid in a patient sample, following amplification by PCR, is taken as a risk factor for progression to cervical cancer. From the above, it is obvious that cytology and PCR analysis of HPV infection provide very efficient means to detect individuals at risk to develop cervical cancer.
Recently published evidence-based consensus guidelines for the management of women with cervical cytological abnormalities and cervical cancer precursors state that women with atypical squamous cells of undetermined significance (ASCUS) should be managed using a program of 2 repeat cytology tests, immediate colposcopy, or DNA testing for high-risk types of HPV. Testing for HPV DNA is the preferred approach when liquid-based cytology is used for screening.
The limiting factor in order to further decrease the incidence of and mortality from cervical cancer appears therefore to be related to reaching the non attending women and providing a simple sampling device giving relevant samples for HPV analysis and/or cytology.
Traditionally, sampling of vaginal smear requires scraping of a woman's cervix with a sampling device, such as a spatula or a brush. This sampling is generally performed by medical professionals like gynecologists, midwifes or nurses in a clinical environment. Many women, who now refrain from such gynecological testing, would participate if the sampling could be carried out at home and/or by the women themselves. Self and home sampling would therefore increase the participation in the gynecological screening, and by that means, decrease the incidence of cervical cancer.
In addition to the above, sampling systems are also in demand for DNA analysis. Law enforcement officials, paternity agents, etc. are constantly taking DNA samples to help solve crimes, determine paternity, etc. As the results of the tests done on these samples dramatically affect people's lives and may be desired as evidence in legal proceedings, the sampling must be done in a manner in which the sample contamination is reduced or avoided. As such, there is a need for an improved sampling system.
SUMMARY OF THE INVENTIONIn view of the need for an improved sampling device and a system easily adaptable to present health screening procedures, the present invention therefore provides improvement over the currently available devices and systems.
In one embodiment, the present invention comprises a sampling system comprising: a) a mailing package; b) a cell sampling device comprising: i) a flexible shaft having a handle at one end, wherein the shaft is configured to allow an individual to self collect a cell sample from mucous tissue, and ii) a sample collecting element removably connectable with the other end of the shaft and operable to collect a cell sample from mucous tissue of an individual; and c) a sealable unit, wherein the unit is configured to store the sample collecting element having a cell sample thereon and to be received within the mailing package in its sealed form. The sampling system may optionally further include a transport package configured to receive components a)-c) for delivery to a user.
In another embodiment, the present invention comprises a sampling system comprising: a) a mailing package; b) an instruction sheet; c) a flexible shaft; d) a sample collecting element connected with an end of the shaft and having a plurality of raised portions and grooves; e) a bar coded unit including an air tight cover and configured to receive the sample collecting element therein and to be received in the mailing package; and f) a bar-coded transport package configured to receive components a)-e) for delivery to a user.
The sampling systems of the invention may be used by medical personnel for patient sampling and/or may be used by individuals for self-sampling. The sampling systems are particularly advantageous for use by an individual in conduct self-sampling in testing to detect, for example, virus-associated cervical cancer, microbial infections and pathological changes. These and additional embodiments and advantages may be more fully apparent in view of the detailed description.
BRIEF DESCRIPTION OF THE DRAWINGSThe present invention will be more fully understood from the detailed description, given herein below and the accompanying drawings which are given for illustration, and thus not limiting the scope of the invention, and wherein
FIGS. 1A and 1B are, respectively, a front view of mailing package and a rear view of a bar-coded transport package included in one embodiment of the sampling system according to the invention;
FIG. 2 is a top view of a sampling device and a sealable unit held in a protective plastic tray, in accordance with one embodiment of the sampling system of the invention;
FIGS. 3A-3J show schematic plan and cross-sectional views of a sampling device included in one embodiment of a sampling system according to the invention; and
FIG. 4 is an illustration of an instruction sheet suitable for use in accordance with one embodiment of the sampling system of the invention.
The embodiments set forth in the drawings are illustrative in nature and are not intended to be limiting of the invention defined by the claims. Moreover, individual features of the drawings and the invention will be more fully apparent and understood in view of the following detailed description.
DETAILED DESCRIPTIONThe present invention provides a sampling system that overcomes disadvantages of prior art devices, instruments and procedures for obtaining cell samples from mucous tissue such as, but not limited to, the gynecological tract and the mouth.
In a first aspect, the present invention provides a sampling system which may be employed by an individual to easily and reliably, at home or at a visit to a medical location, under hygienic conditions, take cell smears and samples, for example, gynecological samples, from mucous tissues. The samples can be transported without risk of contamination or transmission of infective agents, and thereafter be analyzed by chemical methods, such as PCR, or by other microbiological methods.
With reference toFIGS. 1-4, the sampling system according to one embodiment of the present invention includes acell sampling device2 for taking cell samples, a mailing package14 for returning a sample to, for example, a laboratory for testing, and asealable unit7. Optionally, the sampling system may include atransport package3 for delivery of the sampling system components to a user. One embodiment of thetransport package3 is shown inFIG. 1B, and includes a bar code, for use as described in further detail below. One embodiment of the mailing package14, including a printed address for mailing a sample to the appropriate medical professional, on the front side thereof is shown inFIG. 1A. It will be appreciated that thetransport package3 and the mailing package14 may be provided with this exemplary information, or other information as desired, in any suitable arrangement. The mailing package14 allows return of thesealable unit7 and contents thereof to the appropriate facility, for example, by mail, courier or the like, without compromising the sealable unit or its contents.
In one embodiment, thecell sampling device2 comprises ashaft4 having ahandle5 at one end. The handle may include alower lip5aas shown to facilitate the ease of use of the device. Theshaft4 is configured to allow an individual to self collect a cell sample from mucous tissue. In a specific embodiment, theshaft4 is configured to allow an individual to self collect a sample from a cervix location. In an additional embodiment, at least a portion of the shaft is flexible, and in a further embodiment, a portion of theshaft4 is rigid. Alternatively, the shaft may be entirely flexible. Reference to a flexible shaft is intended to mean at least a portion of the shaft is flexible. In another embodiment, theshaft4 is formed of a polymer, including, for example, polypropylene, polyethylene, or a mixture thereof.
Thecell sampling device2 further comprises asample collecting element6 removably connectable with the other end of theshaft4 opposite the handle. Theelement6 is operable to collect a cell sample from mucous tissue of an individual.FIGS. 3A and 3B show thesample collecting element6 removable connected with theshaft4, whileFIGS. 3C and3E show theshaft4 without thesample collecting element6 thereon andFIGS. 3H and 3I show thesample collecting element6 apart from theshaft4.FIG. 3D shows a cross-sectional view taken along line D-D inFIG. 3C;FIGS. 3F and 3G show cross-sectional views taken along lines F-F and G-G inFIG. 3E, respectively, andFIG. 3J shows a cross-sectional view taking along line J-J inFIG. 3I.
Thesealable unit7 is configured to store thesample collection element6 having a cell sample thereon, preferably in a manner which prevents contamination of theelement6, i.e., in an air tight manner, and to be received within the mailing package14 in its sealed form. In one specific embodiment, theunit7 is a sealable tube.
In an additional embodiment, thetransport package3 and theunit7 each have anidentification element8, for example correlating to the individual from which a sample is made. In a further embodiment, theidentification element8 consists of a bar code.
Theshaft4, the adsorbingsample collecting element6, thesealable unit7, and theunit cover12 can be manufactured of any suitable materials as desired. For example, these components may be formed of the same or different plastic materials. In a further embodiment, a plastic material of thecell sampling device2, preferentially polypropylene, is selected with a flexural modulus giving theshaft4 flexibility to follow the anatomy of the vagina to reach portio vaginalis and at the same time rigid enough to get a close contact between thesample collecting element6 and the mucous tissue ectocervix.
In a specific embodiment as shown inFIGS. 3A,3B and3H-3J, thesample collecting element6 is generally cylindrical. Theelement6 may be configured and sized as desired for a particular sample collection. In one embodiment, theelement6 is generally cylindrical as shown and has a diameter from about 2 to about 20 mm. In one embodiment as shown inFIGS. 3A,3B,3H and3I, the front part of thesample collecting element6 is rounded and may be made very smooth, so as to render it more tissue friendly and easier for introduction into the sensitive tissue of the vagina.
In a further embodiment, thesample collecting element6 comprises at least one raised portion9. In another embodiment, the raised portions of thesample collecting element6 form a plurality of cell andmucous adsorbing segments10. Thesegments10 are separated by at least onegroove11 or a plurality ofgrooves11. In a specific embodiment, thegrooves11 are from about 0.01 to 2 mm in width and in another embodiment, the raised portions9 include an edge at thegroove11 capable of scraping tissue to collect a sample. In an additional embodiment, the raised portions9 forming thesegments10 and thegrooves11 are configured to collect a cell sample and hold the sample within thegrooves11 even during withdrawal of thedevice2 from a body orifice. In a specific embodiment, thesegments10 of thesample collecting element6 have an unpolished surface and, in a specific embodiment, comprise an abrasive surface, for example having a surface roughness of about 1 to 100 μm, to facilitate release of cell-containing mucous, for example, from ectocervix tissue.
In one embodiment, the raised portions9form segments10 which are essentially rectangular in shape by providing thegrooves11 in the longitudinal and transversal directions on thesample collecting element6. However, it is of course possible to providegrooves11 in other geometries, e.g. in spiral or zigzag patterns. In one embodiment, thegrooves11 are substantially narrower than the width of the raised portions9. In one embodiment the width of thegrooves11 does not exceed about 2 mm, and in another embodiment, the width is from about 0.5 to about 0.1 mm. Importantly, thegrooves11 should be able to absorb mucous liquid and cells therein, and maintain these materials in place during retraction of the device from the body orifice.
Thesample collecting element6 is removably connected with one end of theshaft4. Thus, thesample collecting element6 may be connected with the shaft to facilitate obtaining a mucous sample, for example from ectocervix tissue, and may then be removed from theshaft4 for insertion in thesealable unit7. One of ordinary skill in the art will appreciate that various connection configurations may be employed to facilitate the removable connection of thesample collecting element6 with the end of theshaft4. In the specific embodiments shown inFIG. 3A-3J, an end of thesample collecting element6 is provided with anextension13 havingprotrusions15. The end of theshaft4 is correspondingly provided withextensions16 having grooves adapted to receiveprotrusions15 therein in a snap-fit manner. Thus, theextension13 is inserted between theextensions16 in a male-female type manner in which theprotrusions15 are snap fit within grooves contained in theextension16 at the end of theshaft4. The protrusions are released from the grooves contained inextension16 by rotation of thesample collecting element6 as shown inFIG. 3B. As a result, thesample collecting element6 may be removed from theshaft4 to theunit7 and preferably sealed therein, for example with aunit cover12 as shown inFIG. 2. Advantageously, to prevent contamination of thesample collecting element6 once a mucous sample is adhered thereto, the sample collecting element may be at least partially inserted within theunit7, prior to removal of thesample collecting element6 from theshaft4. Theunit7 may then be moved to rotate the sample collecting element as shown inFIG. 3B and release the sample collecting element fromextension16 of theshaft4. After release of the sample collecting element from its connection with theshaft4, the remainder of the sample collecting element is then inserted into theunit7, for example by gravity by holding the sample collection unit an upright vertical position, or by pushing the sample collected element further into the unit with the end of theshaft4. The unit is then sealed with the appropriate cover, preferably to form an airtight seal.
The sealedunit7, having thesample collecting element6 therein, may then be placed in the mailing package14 which is designed to protect the sealed unit during return transport of the sealed unit to a medical facility, for example a doctor's office, hospital or laboratory, for appropriate testing of the collected sample therein.
In one embodiment, the sample collecting system further comprises an instruction sheet20, particularly useful when the sampling system is adapted for self sampling by an individual.
In one embodiment, the sampling system of the invention is configured to allow an individual to self-collect a sample. In an additional embodiment, the self-sampling device is configured to allow an individual to collect a sample from mucous tissue. In another embodiment, the mucous tissue resides in the gynecological tract and in another embodiment the mucous tissue resides in the mouth, (e.g. cheek). The sampling system may be used by distribution to a patient, who conducts sampling and returns the sample for final laboratory analysis according to the present invention.
EXAMPLEThis example examines if the same result will be obtained when gynecological smears are taken by hospital staff using previous standard procedures or using the sampling system according to the present invention, as well as if patients themselves use the sampling system.
Thirty six women are requested to come to the hospital for regular gynecological control and participate in the study. The hospital staff secure gynecological smears from the portio area with the use of a cytobrush. One sample is used for conventional cytological screening and the other for HPV analysis. The women take one sample themselves with the present invention following the written information as shown inFIG. 4. This sample is used for HPV analysis.
All samples are sent to the Department of Pathology, University of Uppsala. The smears collected with cytobrush by the gynecological staff and the smears collected by the women themselves with the device are analyzed for presence of HPV with the Hybrid Capture II method (Digene Diagnostics Inc., Silver Spring, Md., USA). The cytological smears are, after screening, examined for HPV using a PCR based technique.
All samples taken with previous standard procedures are scraped into test tubes and PCR buffer and proteinase K is added. When samples are taken with the device according to the present invention, the PCR buffer and proteinase K are simply added into the sealable unit, either by the user, or prior to delivery of the sampling system to a user, or upon return of the unit to, for example, a testing facility. The cells are digested at 60° C. and the DNA fraction recovered with standard methods.
The PCR amplification is performed in 100 μl volume containing standard amplification reagents. Type-specific PCR amplification is performed under conditions described by Brule et al. using GP5+/GP6+ general primers. Samples with HPV DNA amplicones are sequenced with an ABI PRISM310 Genetic Analyzer (Applied Biosystems, Foster City, Calif.) after which the HPV type can be determined.
The results from these studies demonstrate that the women themselves can readily secure gynecological samples with the device according to the present invention. Furthermore, both cytological and PCR analysis of the samples give essentially the same result as when medical staff take the samples either using the present device or other previously well established sampling methods. It is demonstrated that the analysis can be carried out with satisfactory results three days after sampling with the device.
Thus, the sampling system is particularly advantageous for self-sampling for gynecological samples, and particularly HPV analysis. After self sampling at home, the device may be rapidly returned by mail to a hospital laboratory for HPV analysis. The sampling system according to the present invention is surprisingly well accepted, and is particularly useful for self sampling at home.
The sampling system will increase participation in the gynecological screening programs evaluating the risk of developing cervical cancer in situ. Self and home sampling will be positive from a health-economic point of view, but more importantly, increased participation will decrease the incidence of cervical cancer and also decrease the number of women who die of this disease.
The specific illustrations and embodiments described herein are exemplary only in nature and are not intended to be limiting of the invention defined by the claims. Further embodiments and examples will be apparent to one of ordinary skill in the art in view of this specification and are within the scope of the claimed invention.