Roche DNA Test

Recently the Federal health, Food and Drug Administration regulators in the US cleared the Roche HPV test to detect the Human Papillomavirus in women aged 25 and above. Roche's is primarily a genetic test that could be done as a first-choice screening option for cervical cancer. This is an advance on the decades-old Pap smear.

Roche diagnostics conducted a study that provided the FDA with reasonable assurance of the safety and effectiveness. Roche's trial included 47,000 women who underwent cervical screening using either Pap or HPV screening. The results were checked for accuracy against final biopsy results that confirmed whether they actually had cancer.

As such doctors use DNA-based tools as a follow-up to confirm Pap smear results. Now, Roche DNA test can be used as a first-choice option for cervical cancer screening, ahead of the Pap test.

The FDA approval comes despite warning from health advocates that approving the DNA test as an alternative to Pap could lead to confusion, higher costs and over treatment of younger women who carry the virus that have little risk of developing actual cancer.

While Roche supported its study results suggesting that genetic testing is more accurate and objective at identifying cancerous growth than the Pap smear, there are no major medical guidelines that recommend HPV testing alone for cervical cancer screening. Some physicians and gynecologists advice holding off using the test until medical societies can provide guidance to some key questions which include how frequently it should be used.

Pap test was the only available screening option for cervical cancer for decades. Due to increased Pap screening, in the US, the number of reported cases of cervical cancer has decreased more than 50 percent in the past 30 years. Yet, an estimated 12,000 cases of cervical cancer are expected to be diagnosed this year. Hence Roche and other test markers developed HPV tests – although the cost of Roche's HPA is twice and even more as that of the Pap which is $ 40.

The American Cancer Society has tried to evolve latest guidelines incorporating both techniques. A Pap test is recommended every three years for those aged between 21 and 29 years of age and older women should have both a Pap test and an HPV test every five years, or only a Pap every three years. Also, according to FDA, women who test positive for HPV 16 or 18 should proceed directly to colposcopy, which is an invasive procedure in which the cervix is viewed with a magnifying device and often tissue sample is collected for testing. A positive test for one or more of the other 12 high-risk HPV strains should be followed by a Pap test to determine the need for colposcopy.

As women in their 20s could be exposed to the danger of more invasive testing that could leave the cervix less able to handle pregnancy later in their life if they undergo a HPV screening, they are advised not to do so.

Roche DNA test claims to have the superior ability to detect HPV DNA and individual types. It is also capable of detecting HPV genotypes present in multiple infections. This can occur in up to 35% patient samples. It uses standardized and quality controlled reagents to do the test. Due to co amplification primer concentrations are used. This minimizes competition.

It helps identify women at risk and optimizes treatment strategies. It helps further stratify women with normal cytology who are HPV positive into different categories. The test also provides physicians with actionable information to treat the highest risk patients immediately.

PCR - Polymerase Chain Reaction

Polymerase Chain Reaction is a technique to amplify small segments of DNA for molecular and genetic analysis. These amplified DNA can be used by laboratory procedures. The entire cycling process of PCR is automated and can be completed in just a few hours - guided by a temperature altering system known as thermocycler.

The polymerase chain reaction (PCR) test can measure the presence of viral nucleic acids in the patient’s blood even when there is no detectable antibody. Numerous copies of a gene are made by separating the 2 strands of DNA containing the gene segment, marking its location, using DNA polymerase to make multiple copies. PCR test is used to evaluate false negative results to the ELISA and Western blot tests.The PCR test can detect the presence or absence of antigens by determining whether cells have the genes for the antigens.

PCR test is becoming first choice of techniques for the detection of many bacteria/virus - from Anthrax to SARS-CoV-2. PCR technique is a major tool in the ongoing fight against the Covid-19 pandemic. It helped to positively match the specific coronavirus present in the lung tissue, blood and feces of infected animals to the exposure virus.
Even most mapping techniques in the Human Genome Project (HGP) relied on PCR.

Reverse Transcription Polymerase Chain Reaction (RT-PCR): Reverse Transcription Polymerase Chain Reaction is a method of polymerase chain reaction amplification of nucleic acid sequences that uses RNA as the template for transcribing the corresponding DNA using reverse transcriptase. It (RTPCR) relies on chemical analysis of the substance in the body that transmits genetic information (RNA) to:

• Evaluate the effectiveness of cancer therapies
  
• Identify mutations consistent with the presence of Ewing’s sarcoma
  
• Reveal cancer that recurs after treatment has been completed
  

Paternity test

To determine the genetic relationship between any two or more individuals, their blood samples are taken and analyzed in a lab to compare their DNA profiles. This paternity testing can be done even before the birth of a child or after it is born or even when there is a need to determine the parentage of a child. The DNA paternity testing will detect the true biological father or mother when there is any dispute about it. Amniocentesis and Chorionic Villus Sampling are conducted for DNA paternity test.

Another paternity test involves a small amount of maternal blood sample to detect the paternity. Blood samples are collected from members who are going to be tested, including the mother in the laboratory. Primordial fetal cells are separated from the maternal blood sample using an extraction procedure. These primordial fetal cells can be extracted after 12 weeks of fetal gestation. It is found that this procedure is safer and less expensive than the other two tests. Since women who had delivered babies earlier will have fetal cells of their earlier pregnancies for about 20 years, this non-invasive test is often resorted to.

Paternity test using umbilical cord blood is done at the time of delivery to find out the paternity of a child. There is no risk involved in this test for the infant. Paternity testers will get you a kit to collect the umbilical cord blood and this can be forwarded to the physician before the delivery. Results of this test will be available in 3 to 5 days. There are home kits available to do paternity testing and they are not legally binding.