Phenotype (clinical medicine)

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In a nosological sense, the term phenotype can be used in clinical medicine for speaking about the presentation of a disease. [1] The complementary concept in this regard is endotype, which refers to the pathogenesis of the disease ignoring its presentation. [2]

Contents

In this context, a phenotype would be any observable characteristic or trait of a disease, such as morphology, development, biochemical or physiological properties, or behavior, without any implication of a mechanism. A clinical phenotype would be the presentation of a disease in a given individual.[ citation needed ]

Some organizations have their own specialised meaning. For example, the term 'phenotype' in the field of chronic obstructive pulmonary disease (COPD) means "a single or combination of disease attributes that describe differences between individuals with COPD as they relate to clinically meaningful outcomes", [3] but nearly all specialities use this meaning in some way, like in asthma research. [4]

Etymology

The word phenotype comes from Greek phainein 'to show',and typos 'type'. Normally it refers to the presentation of a trait in an individual, but in this case it means the presentation of a disease entity.

See also

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Cough Sudden expulsion of air from the lungs as a reflex to clear irritants

A cough is a sudden expulsion of air through the large breathing passages that can help clear them of fluids, irritants, foreign particles and microbes. As a protective reflex, coughing can be repetitive with the cough reflex following three phases: an inhalation, a forced exhalation against a closed glottis, and a violent release of air from the lungs following opening of the glottis, usually accompanied by a distinctive sound.

Alpha-1 antitrypsin deficiency Medical condition

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Rhinitis Irritation and inflammation of the mucous membrane inside the nose

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Non-invasive ventilation

Non-invasive ventilation (NIV) is the use of breathing support administered through a face mask, nasal mask, or a helmet. Air, usually with added oxygen, is given through the mask under positive pressure; generally the amount of pressure is alternated depending on whether someone is breathing in or out. It is termed "non-invasive" because it is delivered with a mask that is tightly fitted to the face or around the head, but without a need for tracheal intubation. While there are similarities with regard to the interface, NIV is not the same as continuous positive airway pressure (CPAP), which applies a single level of positive airway pressure throughout the whole respiratory cycle; CPAP does not deliver ventilation but is occasionally used in conditions also treated with NIV.

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Bronchoconstriction is the constriction of the airways in the lungs due to the tightening of surrounding smooth muscle, with consequent coughing, wheezing, and shortness of breath.

Respiratory disease Disease of the respiratory system

Respiratory diseases, or lung diseases, are pathological conditions affecting the organs and tissues that make gas exchange difficult in air-breathing animals. They include conditions of the respiratory tract including the trachea, bronchi, bronchioles, alveoli, pleurae, pleural cavity, the nerves and muscles of respiration. Respiratory diseases range from mild and self-limiting, such as the common cold, influenza, and pharyngitis to life-threatening diseases such as bacterial pneumonia, pulmonary embolism, tuberculosis, acute asthma, lung cancer, and severe acute respiratory syndromes, such as COVID-19. Respiratory diseases can be classified in many different ways, including by the organ or tissue involved, by the type and pattern of associated signs and symptoms, or by the cause of the disease.

Bronchitis Inflammation of the large airways in the lungs

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An endotype is a subtype of a health condition, which is defined by a distinct functional or pathobiological mechanism. This is distinct from a phenotype, which is any observable characteristic or trait of a disease, such as development, biochemical or physiological properties without any implication of a mechanism. It is envisaged that patients with a specific endotype present themselves within phenotypic clusters of diseases.

Chronic obstructive pulmonary disease Lung disease involving long-term poor airflow

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The Dutch hypothesis provides one of several biologically plausible explanations for the pathogenesis of chronic obstructive pulmonary disease (COPD), a progressive disease known to be aetiologically linked to environmental insults such as tobacco smoke.

Ravi Kalhan is the director of the Asthma and COPD Program at Northwestern University Feinberg School of Medicine and Northwestern Memorial Hospital.

Emphysema Medical condition

Emphysema, or pulmonary emphysema, is a lower respiratory tract disease, characterised by air-filled spaces (pneumatoses) in the lungs, that can vary in size and may be very large. The spaces are caused by the breakdown of the walls of the alveoli and they replace the spongy lung parenchyma. This reduces the total alveolar surface available for gas exchange leading to a reduction in oxygen supply for the blood. Emphysema usually affects the middle aged or older population because it takes time to develop with the effects of tobacco smoking, and other risk factors. Alpha-1 antitrypsin deficiency is a genetic risk factor that may lead to the condition presenting earlier.

MFAP4 is an extracellular matrix protein encoded by the MFAP4 gene. It is part of the MFAP family of proteoglycans, which are involved in cell adhesion, intercellular interactions and the assembly and/or maintenance of elastic fibres.

Stephanie J. London American physician

Stephanie J. London is an American epidemiologist and physician-scientist specializing in environmental health, respiratory diseases, and genetic susceptibility. She is the deputy chief of the epidemiology branch at the National Institute of Environmental Health Sciences.

Smokers macrophages

Smoker’s macrophages are alveolar macrophages whose characteristics, including appearance, cellularity, phenotypes, immune response, and other functions, have been affected upon the exposure to cigarettes. These altered immune cells are derived from several signaling pathways and are able to induce numerous respiratory diseases. They are involved in asthma, chronic obstructive pulmonary diseases (COPD), pulmonary fibrosis, and lung cancer. Smoker’s macrophages are observed in both firsthand and secondhand smokers, so anyone exposed to cigarette contents, or cigarette smoke extract (CSE), would be susceptible to these macrophages, thus in turns leading to future complications.

Pulmonary drug delivery

Pulmonary drug delivery is a route of administration in which patients use an inhaler to inhale their medications and drugs are absorbed into the bloodstream via the lung mucous membrane. This technique is most commonly used in the treatment of lung diseases, for example, asthma and chronic obstructive pulmonary disease (COPD). Different types of inhalers include metered-dose inhalers (MDI), dry powder inhalers (DPI), soft mist inhalers (SMI) and nebulizers. The rate and efficacy of pulmonary drug delivery are affected by drug particle properties, breathing patterns and respiratory tract geometry.

References

  1. Scheuermann, Richard H.; Ceusters, Werner; Smith, Barry (2009-03-01). "Toward an Ontological Treatment of Disease and Diagnosis". Summit on Translational Bioinformatics. 2009: 116–120. PMC   3041577 . PMID   21347182.
  2. Russell, CD; Baillie, JK (April 2017). "Treatable traits and therapeutic targets: Goals for systems biology in infectious disease". Current Opinion in Systems Biology. 2: 140–146. doi:10.1016/j.coisb.2017.04.003. ISSN   2452-3100. PMC   7185428 . PMID   32363252.
  3. Miravitlles, Marc; Calle, Myriam; Soler-Cataluña, Juan José (2012-03-01). "Clinical Phenotypes of COPD: Identification, Definition and Implications for Guidelines". Archivos de Bronconeumología (English ed.). 48 (3): 86–98. doi:10.1016/j.arbr.2012.01.003. PMID   22196477.
  4. Bel, Elisabeth H. (January 2004). "Clinical phenotypes of asthma". Current Opinion in Pulmonary Medicine. 10 (1): 44–50. doi:10.1097/00063198-200401000-00008. PMID   14749605.