What is HER-2/neu?

The HER-2/neu oncogene (erbB-2) encodes a protein with a molecular weight of 185,000 daltons (p185). This oncogene belongs to a family of cell surface receptors with intracellular tyrosine kinase activity, and is structurally related to the Epidermal Growth Factor Receptor (erbB-1). The HER-2/neu protein is composed of a cytoplasmic domain, a transmembrane domain, and an extracellular domain (ECD). Since the mid-1980s the HER-2/neu oncogene and its protein product have been reported to play a role in the development and metastasis of breast cancer.  The shed ECD has been shown to be a glycoprotein, usually referred to as p105, with a molecular weight ranging from 97 kilodaltons to 115 kilodaltons. Numerous reports have shown that ECD is shed in the blood of normal individuals and is elevated in a subset of women with metastatic breast cancer. In addition, there are reports that HER-2/neu protein is overexpressed in a number of other tumor types of epithelial origin, including lung, hepatocellular, pancreatic, colon, stomach, ovarian, cervical, and bladder cancer.

Intended Use

HER-2/neu values obtained may be used in the follow-up and monitoring of patients with metastatic breast cancer whose initial serum HER-2/neu level is greater than 15 ng/mL.

HER-2/neu values should be used in conjunction with information available from clinical and other diagnostic procedures in the management of breast cancer. The clinical utility of the measurement of HER-2/neu in serum as a prognostic indicator for early recurrence and in the management of patients on immunotherapy has not been fully established. This test should be used by or under the order of a physician. This assay is not intended for use on any other system.

Method

A fully automated, two-site sandwich immunoassay using direct, chemiluminescent technology.

Sensitivity

The ADVIA Centaur HER-2/neu assay measures HER-2/neu concentrations in serum up to 350 ng/mL with a minimum detectable concentration (analytical sensitivity) of 0.5 ng/mL.

Analytical sensitivity is defined as the concentration of HER-2/neu that corresponds to the RLUs that are two standard deviations more than the mean RLUs of 20 replicate determinations of the HER-2/neu zero standard. This response is an estimate of the minimum detectable concentration with 95% confidence.

Specificity

The potential interference of therapeutic agents was tested by adding these substances to two serum pools containing approximately 15 ng/mL and 125 ng/mL of HER-2/neu. The therapeutic agents were spiked into these serum pools to the final concentration indicated in the following table. These spiked pools were assayed for HER-2/neu and the percent recovery to the unspiked pool was calculated.

Substance Amount	Added (ug/mL)	Mean % Recovery
Cis-Platinum	175	99.2
Cyclophosphamide	800	102.2
Diethylstilbesterol	25	99.2
Doxorubicin HCl	50	99.5
Etoposide	10	100.6
5-Fluorouracil	1	102.4
Herceptin	400	100.4
Megestrol acetate	10	99.2
Methotrexate	500	103.5
Mitomycin C	75	102.6
Paclitaxel	50	99.8
Tamoxifen	60	97.1
Vinblastine	1.5	99.7
Vincristine	1.5	99.3

Interference testing was determined according to NCCLS Document EP7-P.29.

Cross reactivity with human Epidermal Growth Factor Receptor (EGFR or HER-1) at levels up to 10,467 ng/mL was negligible at 0.04%

Reference Ranges

<15.2 ng/mL.

Specimen Required

5 mL serum

Please feel free to contact us for more details.

ASACIR^TM  TB

Interferon Gamma Release Assay by Blood Test, a new way for diagnosing TB infection

In the past, direct smear and culture method may be used for TB diagnosis especially for pulmonary infection. The test may be sensitive if the patient is heavily infected with the tuberculi. For ex-pulmonary or Latent TB infection (LTBI), the sensitivity is much lower. The Latent TB was also found to be associated with increased risk in infertility and Diabetes Mellitus. The Tuberculin Skin Test (TST) is also commonly used for mass screening of LTBI or asymptomatic persons. It demonstrates cross-reactivity with BCG vaccination result. It also requires special skill in intradermal injection of test material and reading of the response size in second visit of the patient.

The A.TB offers an alternative method to detect TB infection by measuring the release of interferon-gamma (IFN-g) in heparinized whole blood from target person. Interferon-gamma release assays are valuable over the traditional tuberculin skin test in the screening latent TB infection among close TB contacts, silicosis patients, HIV-infected subjects, and immuno-compromised individuals including those under treatment with anti-TNF agents (such as ankylosing spondylitis, rheumatoid arthritis).  The sensitivity (83%) is improved . Testing time (2 days) is shortened. The interferon gamma test is accepted as complementary tests for Latent TB infection in CDC and NHS guidelines.  It offers a simple blood test by just collecting 3ml of venous blood in heparin bottle.

References:

1. Tuberculosis Manual by HKSAR 2006

<<http://www.info.gov.hk/tb_chest/doc/Tuberculosis_Manual2006.pdf>>

2. Annual report 2009 Tuberculosis & Chest Service of the Department of Health

<<http://www.info.gov.hk/tb_chest/doc/AnnualReport2009.pdf>>

3. Tuberculosis, Clinical diagnosis and management of tuberculosis, and measures for its prevention and control by NHS Mar 2011

<<http://www.nice.org.uk/nicemedia/live/13422/53642/53642.pdf>>

4. Updated Guidelines for Using Interferon Gamma Release Assays to Detect Mycobacterium tuberculosis Infection-United States, 2010

<<http://www.cdc.gov/mmwr/pdf/rr/rr5905.pdf>> 

5. Consensus Statements on the Indications and Monitoring of Anti-tumor Necrosis Factor (TNF) Therapy for Rheumatic Diseases in Hong Kong

<<http://www.rheumatology.org.hk/database/publication/2005vol5no1jul05p1925.pdf>>

Ordering information: Test Code ATB

In response to the increasing demand of measurement HBV-DNA in serum to identify individuals with high viral replication, to monitor patients on therapy, and to monitoring the efficiency antiviral therapy, PHC is now offering a better service at a better discount rate to benefit your valued patients.

The quantitative real time PCR assay for the detection of HBV-DNA is a highly sensitive method. The dynamic ranges of real time PCR assays usually range from 10² - 10⁸ genome equivalents per litre (geq/l) of HBV-DNA in serum with a good linearity. Our real time PCR detection limit is from 2 x 10² IU/mL to 5.88 x 10⁷ IU/mL

The presence of Hepatitis B surface antigen (HBsAg) in serum indicates HBV infection, but does not provide information on the replicative state of the virus. Naturally occurring escape mutants of HBV with various mutations in the S gene could have no detectable HBsAg in serum [1]. Further, DNA-positive HBsAg seronegative individuals are not uncommon. Hepatitis B e antigen (HBeAg) has been considered a viral replicative marker, but the precore point mutant HBVs cause a HBeAg negative phenotype irrespective of their status of replication [2]. The level of HBV-DNA in serum or plasma has been shown to correlate with biochemical and histological measures of disease, and probably reflects more accurately the replicative activity of HBV. The HBeAg status does not necessarily reflect the HBV-DNA level in the serum, which is in agreement with previous study [3]

Reference:

1. Yamamoto K, Horikita M, Tsuda F, et al. Naturally occurring escape mutants of hepatits B virus with various mutations in the S gene in H B seropositive for antibody to hepatitis B surface antigen. 1994. J Virol 68:2671-6.

2. Gitlin N. Hepatiits B:Diagnosis prevention and treatment. ClinChem 1997;43:1500-6.

3. Zaaijer HL, ter Borg F, Cuypsers HT, Hermos MG, Lelie PN. Comparison of methods for detection of hepatitis B virus DNA.J Clin Microbiol 1994;32:2088-91.

Systematic autoimmune disease is characterized by the presence of circulating autoantibodies directed to a wide variety of cellular antigens. Systemic lupus erythematosis (SLE), commonly referred to as Lupus, is the best known of these diseases. Other possible connective tissue diseases include mixed connective tissue disease (MCTD), Sjogren syndrome, sclerodema, and polymyositis/dermatomyositis. The majority can be diagnosed by clinical presentation and their antibody profiles to the various antigens involved, which include dsDNA, Sm, RNP, SS-A(Ro), SS-B(La), Scl-70, Jo-1, and Histones. The current method for testing of Anti-ENA offer the screening for antibodies to a mixture of Sm, RNP, Ro, La, Scl-70 and Jo-1.

Anti-Ro (SS-A) and AntiLa (SS-B) were first described in the 1960s and have been found in a variety of systemic rheumatic diseases, particularly SLE and Sjogren syndrome.

One important clinical correlation with anti-Ro (SS-A) is neonatal lupus. Women with SLE considering pregnancy may be screened for anti-Ro (SS-A) so that pregnancies can be closely monitored.

The presence of anti-Ro (SS-A) and anti-La (SS-B) antibodies can be used to support the diagnosis of Sjogren syndrome. Evidence also showed that 60% of Sjogren syndrome are associated with anti-Ro or anti-La.

Scl-70 antibodies are usually present in the diffuse subtype of scleroderma while antibodies to centromere proteins are dominant in the limited subtype of scleroderma or CREST syndrome.

Approximately 30% of patients with polymyositis (PM) and 10% of patients with dermatomyositis (DM) have antibodies to Jo-1.

What is Vitamin D?

Vitamin D is a commonly used collective term for a family of closely related seco-steroids. Upon exposure to sunlight. 7-dehydro-cholesterol, located deep in the actively growing layers of the epidermis, undergoes photolytic cleavage of the B-ring to yield pre-vitamin D₃ which is isomerised to vitamin D₃ (cholecalciferol). Vitamin D₃ and vitamin D₂ (ergocalcifierol) may also be obtained by dietary supplementation or from a limited number of foods. Vitamin D₂ is metabolized in a similar way to vitamin D₃.

Intended Use

Serum concentration of 25-OH D is considered to be the most reliable measure of overall vitamin D status and thus can be used to determine whether a patient is vitamin D sufficient. Assessment of vitamin D status may be required to determine the cause of abnormal serum calcium concentrations in patients. A new study suggests many Americans are not getting anywhere nearly enough of the vitamin, and it may be affecting their heart health.

Method

An antibody competitive immunoassay

Sensitivity

The Vitamin D Total Assay had an LoB of 1.60 ng/mL (4.0 nmol/L), an LoD of 3.20 ng/mL (8.0 nmol/L), and an LoQ of 3.52 ng/mL (8.8 nmol/L). The LoD is defined as the lowest concentration of 25(OH) vitamin D that can be detected with 95% probability.

Specificity

The ADVIA Centaur VitD Total assay shows high specificity for 25(OH) vitamin D2 and 25(OH) vitamin D3. The following compounds were tested with total 25(OH) vitamin D concentrations of 20 and 50 ng/mL. Percent change is calculated as:

Percent cross-reactivity = (corrected assay value / amount of compound spiked) x 100

The following results were obtained:

Compound	Concentration (ng/mL)	Cross-Reactivity (%)
1, 25 (OH)2 Vitamin D2	100	3.5
1, 25 (OH)2 Vitamin D3	100	1.2
25 OH Vitamin D2	30	106.2
25 OH Vitamin D3	30	97.4
Paricalcitol	24	0.1
3-epi-25-OH Vitamin D3	100	1.0
Vitamin D2	100	0.5
Vitamin D3	100	0.3

Reference Ranges

	Range
Level	nmol/L	ng/mL
Deficient	<25	<10
Insufficient	25-74	10-29
Sufficient	75-250	30-100
Potential Intoxication	>250	>100

Specimen Required

5 mL serum

Please feel free to contact us for more details.

What is allergy?

An allergy is a hypersensitivity to foreign substances which can produce a violent reaction in the allergy sufferer.  It is a group of disorders distinguished by the way the body's immune system responds to specific allergen proteins.  The reaction is caused by an allergic antibody called IgE (Immunoglobulin E), which is found in people with allergies.

Types of allergy

l    Atopy - Including asthma, rhinitis, and dermatitis.  More than 15% of the populatino in industrial countries suffer from these immediate-type allergic symptoms

l    Food Allergy - Reaction which leads to symptoms within hours of having ingested the food.  Main food allergens include peanuts, milk, egg, bird's nest, etc.

l    Inhalation Allergy - Usually caused by seasonal allergens (such as grass or weeds) or perennial allergens (dust mites, dander of household pets, etc.)

How to prevent allergy?

There is only one way to prevent allergy!  It is to find out the allergens, and to avoid making direct, and possibly, indirect contact with what you are allergic to.

Sometimes allergy can lead to fatal death.  Therefore, 4 Comprehensive Allergy Profiles have been introduced to protect you, by letting you know what you should keep away from.

Should you have any enquiries, please contact related salesperson or e-mail us at: info@phclab.com.hk

What is Ketamine?

Ketamine is a dissociative anesthetic developed in 1963 to replace PCP (Phencyclidine). While Ketamine is still used in human anesthesia and veterinary medicine, it is becoming increasingly abused as a street drug.

The effects of Ketamine generally last 4-6 hours following use. Ketamine is excreted in the urine as unchanged drug (2.3%) and metabolites (96.8%).

Intended Use

Detection of Ketamine in human urine at a cut-off concentration of 1,000ng/mL.

Method

An immunoassay based on the principle of competitive binding.

Sensitivity

>99% accuracy at 50% above and 50% below the cut-off concentration of 100ng/mL.

Specificity

The test will detect other related compounds of certain concentrations. The test provides only a qualitative, preliminary analytical result. A more specific alternate chemical method must be used in order to obtain a confirmed analytical result. Gas chromatography/mass spectrometry (GC/MS) is the preferred confimatory method. Clinical consideration and professional judgement should be applied to any drug of abuse test result, particularly when preliminary positive results are used.

Reference Ranges

Negative

Speimen Required

10mL random urine

Please feel free to contact us for more details.