The Food and Drug Administration (FDA) has permitted marketing of CD Diagnostics’ Synovasure Lateral Flow test kit for the detection of joint replacement infection, making this the first FDA-authorized diagnostic that helps determine whether the inflammation around a prosthetic joint is due to an infection or another cause. Specifically, the test is designed to help healthcare providers evaluate patients for revision surgery, a procedure to replace or compensate for a failed joint implant. Physicians typically evaluate for potential infections using X-ray images or laboratory analysis of joint fluid, the latter of which can take days to produce results. The Synovasure Lateral Flow test kit, in contrast, provides results in approximately 10 minutes by detecting proteins in patients’ synovial fluid called human alpha defensins. These antimicrobial proteins are released by activated neutrophils in response to infection. The test is not intended, however, to identify a specific type of infection.
FDA reviewed the Synovasure Lateral Flow test kit through the de novo premarket review pathway. For this review, the agency looked at data from a clinical study that analyzed 305 prospective synovial fluid samples collected from individuals who had total knee or hip joint replacements and who were being evaluated for revision surgery. The study showed that, among subjects with an infection diagnosis based on standard of care criteria, the Synovasure Lateral Flow test kit identified 89.5% as positive for alpha defensins.
FDA Authorizes First Blood Test for Zika Virus Antibodies
InBios International has received de novo Food and Drug Administration (FDA) authorization for the ZIKV Detect 2.0 IgM Capture enzyme-linked immunosorbent assay (ELISA), making this the first blood test for Zika virus immunoglobulin M (IgM) antibodies that FDA has allowed to be marketed in the U.S. Tests for IgM antibodies are able to detect Zika infection early because the body produces these antibodies during its initial immune response to the virus. Prior to this decision, however, FDA had only granted emergency use authorization to InBios’s test and the four other existing tests for Zika virus IgM antibodies. To evaluate the ZIKV Detect 2.0 IgM Capture ELISA, FDA reviewed data from a clinical study of 807 test samples and a variety of analytical studies. The agency does caution, though, that the test might give false-negative results for specimens collected before day four after the onset of Zika symptoms or after the window of detectable IgM closes.
Beckman Coulter Sends Out Second Recall Notice for Hematology Analyzers
The Food and Drug Administration (FDA) is alerting hospitals, laboratories, and other healthcare providers of a Class I recall of Beckman Coulter’s DxH 800, DxH 600, and DxH 900 hematology analyzers. Beckman Coulter first initiated this recall in August 2018 after the company received complaints that these analyzers gave erroneously elevated platelet results without an accompanying error message. Not all labs responded to Beckman Coulter’s initial recall notification, however. FDA therefore recently asked the company to send a second urgent medical device correction letter to customers, which went out on May 20. Beckman Coulter also continues to investigate the unflagged elevated platelets issue and assess potential causes. The company has indicated to customers that a software update to these analyzers may help reduce the risk of inaccurate results. FDA has not yet evaluated this software, though, and is working with the company to determine whether the software update alone will solve this problem.
WHO Approves Abbott’s Point-of-Care HIV Viral Load Test
Abbott has received World Health Organization (WHO) prequalification approval for the m-PIMA HIV-1/2 VL, a point-of-care test for HIV viral load. WHO recommends that all HIV patients receiving antiretroviral therapy (ART) undergo a viral load test—the gold standard for monitoring ART treatment failure—at 6 months and 12 months, and then annually thereafter if the individual is stable on ART. However, in certain resource-limited countries in sub-Saharan Africa, Asia, and Latin America, very few people have access to viral load testing. Abbott’s m-PIMA HIV-1/2 VL is designed to increase the availability
of this testing in these areas. As a quantitative nucleic acid amplification test, it measures viral load for HIV type 1 groups M/N and O, and HIV type 2 in plasma samples. It is also designed to deliver results in under 70 minutes while the patient is still present. This quick turnaround time should be particularly valuable for monitoring the viral load of HIV-positive pregnant women, according to Abbott.
FDA Gives OK to Hologic, Cepheid for Extragenital Chlamydia, Gonorrhea Tests
The Food and Drug Administration has granted 510(k) clearance to Hologic for the Aptima Combo 2 assay and to Cepheid for the Xpert CT/NG, making these the first tests to receive FDA clearance for detecting Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) in extragenital specimens from the throat and rectum. The Aptima Combo 2 is a nucleic acid amplification test that detects the ribosomal RNA of CT and NG, while the Xpert CT/NG uses qualitative real-time polymerase chain reaction to detect a unique CT target and two independent NG targets. These tests were previously cleared for testing urine, vaginal, and endocervical samples. To evaluate the devices for this new indication, FDA reviewed clinical data collected through a multisite, cross-sectional study that evaluated the diagnostic accuracy of multiple commercially available nucleic acid amplification tests for CT and NG when using throat and rectal specimens.
FDA Clearance, CE Mark Granted to DiaSorin Tests for VZV, HSV
DiaSorin Molecular has received Food and Drug Administration clearance for its Simplexa VZV Direct assay and has received CE marking for its Simplexa HSV 1/2 & VZV Universal Direct assay. Both of these tests are designed to run on DiaSorin’s Molecular Liaison MDx instrument. The Simplexa VZV Direct detects the polymerase gene of the varicella-zoster virus (VZV) and aids in the diagnosis of both meningitis and encephalitis caused by VZV. The test uses 50 μL of cerebrospinal fluid (CSF) and has a greater than 98% agreement with polymerase chain reaction/bidirectional sequencing for VZV in CSF samples. Meanwhile, the Simplexa HSV 1/2 & VZV Universal Direct assay detects and differentiates between herpes simplex virus (HSV)-1, HSV-2, and VZV DNA from cutaneous and mucocutaneous swab specimens. This test also demonstrated a greater than 98% agreement with another CE-marked nucleic acid amplification test.