Immunology

Alzheimer's disease: CSF and plasma biomarkers

Alzheimer's disease is a progressive neurodegenerative disorder that is the most common cause of dementia worldwide.

Biomarkers in CSF and plasma allow for diagnosis in preclinical and mild clinical stages of the disease, and in the future will be essential for monitoring neurological changes in response to drugs that prevent disease progression.

Use of preoteinogram: Keys for demand optimization

The proteinogram is the main method for detecting and monitoring monoclonal components (MC) in patients with suspected or affected monoclonal gammopathy (MG). Average age MG diagnosis is 65 years, with an overall incidence of 65 cases/100,000 inhabitants/year in those over 60 years of age, and 5 cases/100,000 inhabitants/year in those under 60 years of age. Due to the marked difference in incidence based on age, Clinical Laboratory Societies indicate that it is not necessary to request this test in patients <50 years of age if there is no clinical suspicion of GM, nor to perform GM screening in the general population, given the lack of data supporting an improvement in patient prognosis. However, in daily clinical practice, we encounter many requests for proteinograms in contexts other than GM screening.

Antiphospholipid antibodies: detection and clinical relevance

In the laboratory, what classically defines Antiphospholipid Syndrome (APS) is the persistent presence of so-called antiphospholipid antibodies. These constitute a heterogeneous family of autoantibodies that are directed against proteins that intervene in the coagulation cascade and that have an affinity for phospholipids on cell surfaces. Antibodies with the greatest clinical relevance are those included in the laboratory requirements of the APS classification criteria. These antibodies, called classical antiphospholipid antibodies, are anti-cardiolipin and anti-β2-glycoprotein I of isotype IgG and IgM and lupus anticoagulant. In addition to these antibodies included in the classification criteria, antibodies against other phospholipids and cofactors, against specific domains of the cofactors or IgA isotype have also been described. These new antibodies, or non-classical antiphospholipid antibodies, have clinical significance yet to be established and their possible etiopathogenic role is much less known. Below we will review detection and relevance of these antibodies.

Methodology to avoid Daratumumab interference on Proteinogram interpretation.

Multiple Myeloma (MM) is the second most common blood malignancy and accounts for 1% of all types of cancer. Among the new drugs used in the treatment of this pathology are monoclonal antibodies. Since the appearance of therapies with these biological drugs, such as Daratumumab as the first line of action. It has been found interference caused by the use of these monoclonal antibodies making laboratory tests a bit more challenging.

Below we explain how we solve this interference in Catlab to achieve a correct interpretation and evaluation of the results.

Detection of Gluten immunogenic peptides

Strict gluten-free diet is the only way to control coeliac disease, since classical serological markers show little effectiveness to specific changes in the diet and do not always correlate with the state of the intestinal villi. Evaluating the excretion of gluten immunogenic peptides (GIP) constitutes specific evidence of gluten consumption, allowing both the control and diagnosis of complex cases.

At Catlab GIP detection is carried out by immunochromatographic method in stool sample. This test shows a detection limit of 0.15 μg GIP / g of sample and has the ability to specifically detect the toxic fraction of prolamins with a specificity close to 100%.

INMUNOLOGÍA -

Immune response and COVID-19

The clinical presentations of COVID-19 range from asymptomatic forms to a syndrome with cytokine release, respiratory failure, and death. People over 60 years old and those with comorbidities, are more susceptible to developing a deficient immune response, unable to eliminate the virus, and responsible for cytokine release syndrome.

However, other host factors, some still unknown, and some likely genetic in nature, appear to confer susceptibility to complications.

IMMUNOLOGY - Diagnostic utility of the Kappa Index in Multiple Sclerosis

Today there are still no optimal biomarkers to identify all those affected by Multiple Sclerosis (MS). Numerous studies show that the quantitative analysis of kappa free chains can be of great help in predicting Isolated Neurological Syndrome, which is usually the first clinical outbreak that leads to the diagnosis of MS. In our laboratory, in addition to the kappa light chains in CSF and serum, we also have the determination of the Kappa Index.

IMMUNOLOGY - Microarray-specific IgE Detection.

Since July, we have in Catlab a Microarray to detect specific IgE. It is a miniaturized solid phase immunoassay based on modern biochip technology, where the allergic components are immobilized in a microarray. This modern technology allows the simultaneous measurement of IgE antibodies against a fixed panel of 112 components of more than 50 allergic sources (food, pollen, latex, epithelia ...), using only 30 μl of serum or plasma.

IMMUNOLOGY - Review of Prenatal Screening in Catlab

Since September 2015, the first-trimester prenatal screening for Down syndrome and Edwards syndrome, is done with a new method and a new calculation program. A comparative between the previous program Lifecycle Perkin Elmer and the new Ssdwlab6 Roche was made satisfactorily. And minimum requirements for imprecision and inaccuracy for biochemical markers were established with the new method of electrochemiluminescence with optimum results.

IMMUNOLOGY - Fecal calprotectin as a marker of inflammatory bowel disease

The clinical suspicion of organic bowel disease motivates a diagnostic colonoscopy that generates a high rate of false positives, because the markers are not very specific. Next january, in Catlab, we will do Fecal Calprotectin (FCP), a protein found in the cytoplasm of neutrophils and in the membrane of activated monocytes and macrophages. The FCP is reliable in discriminating patients likely to suffer inflammatory bowel disease, and to detect endoscopic inflammatory activity. It is also useful to monitor response to treatment and predict the risk of recurrence.