Nguyen Ngoc Gia Linh

Case Study – ‘the Wasp Sting’

Wasps are the order Hymenoptera family which contain venom and poisonous substance can have transmitted to human through a sting (Carl and Max 2016). A 10- year- old girl in the case was stung by a wasp while playing at school. For approximately 20 hours, she had an asymptomatic that includes sharp pain, burning in the initial sensation, redness, swelling and itching. Because the wasp’s venom contains phospholipase A, phospholipase B and mastoparan peptide which effect directly to mast cell degranulation and also release of histamine. In addition, ischemia increases the inflammatory response with subsequent vasodilation and increases capillary permeability with redness at the site of the sting to the patient (Carl and Max 2016). Unfortunately, the patient passed away on day 5 due to systemic inflammatory response syndrome and hypersensitivity. This report will focus on explanation of the innate immune reaction which can disrupt the normal function of each the several stated physiological systems during the development of systemic inflammatory response syndrome (SIRS).

An innate immune system is the adaptive immune responses which can be maintained activation of a pathogen and made of defences against infection (KhanAcademy 2014). There are many types of cell in the innate immune system in order to work together for defendant and protection human body. However, the progression requires in both elements of cellular immunity and humoral immunity. The cellular components consist of lymphocytes with both T cells (CD4⁺ and CD8⁺) and B cells; macrophages; and mast cells. On the other hand, the humoral factors include immunoglobulin E (IgE) and cytokines (Carl and Max 2016). Moreover, the group of blood protein act as disruption of the membrane’s microorganism to produce an inflammatory response and to arrange the forces of the adaptive immune system (Alberts et al. 2002). In this situation, the most influence is mast cells which are found in mucous membranes, connect tissues to heal wound and defence the pathogens via the inflammatory response. Basically, when mast cells are activated, the particle cytokines are released during this process which contains chemical molecules such as histamine, phospholipases, and neurotoxins to produce an inflammatory cascade and act as messenger service or warning for circulating threats (Zhang and An 2009). Some of the venoms of hymenopterous insects include bees, wasps which contain some of the enzymes such as small proteins and peptides; phospholipases and histamine (Voronov et al. 1999). Histamine is going to play a pathophysiological regulatory role in cellular for binding four subtypes of G-protein-coupled receptors (GPCR). Furthermore, histamine produces many of the effects of inflammatory and hypersensitivity that affect increased vascular permeability and smooth muscle contraction. Some above classic symptoms lead to the signs of allergic reaction which cause inducing increased blood flow from capillaries into the tissues and vasodilatation (Benly 2015). In addition, smooth muscles are around the trachea that is contracted by histamine to make difficulty breathe or suffocation (Lauren 2012). However, the dangerous circumstance with the patient makes lots of IgE antibodies in response to wasp toxins that can cause triggers degranulation of mast cells. In such a case, the release blood fluid into the tissues reduces the blood volume that the heart induces inefficiently pump and create a heart attack.

The innate immune response such as systemic inflammatory response syndrome-SIRS disrupts the homeostatic function of following three main systems that include respiratory system, cardiovascular system and renal system. Firstly, a girl patient was diagnosed with SIRS that include reference to acute respiratory distress syndrome (ARDS) or acute lung injury (ALI). ALI and ARDS occur on hypoxia, hypercapnia, acidosis and pulmonary hypertension. These were defined a pulmonary endothelial dysfunction that caused alveolar oedema because of high protein secretion and phagocytic immune cells (Janet et al. 2014). The activity of neutrophils are increased the high concentrations of pro- inflammatory cytokines to migrate damaged endothelium that influence alveolar denudation damage the basal membrane (Janet et al. 2014). Neutrophils are in the lungs which effect of IL-8 and the concentration of cytokine in patients with ARDS is correlated with mortality. Blood carries oxygen and other essential substances to your organs and tissues. However, when the gas exchange functions are failed in oxygenation and carbon dioxide elimination, these are classified hypoxia and hypercapnia. Hypoxia is characterised by an arterial oxygen tension (PaO2) which is lower than 60 mm Hg. Hypercapnia respiratory failure is characterized by a PaCO2 that is higher than 50 mm Hg (David 2000). On the other hand, the decreased blood supply to various cells and tissues due to tissues hypoxia that leads increase in respiratory rate to take in more oxygen. Consequently, the patient was increased respiratory rate of 59 breaths per minute (normally breath rate is 15- 30 breaths per minute with 6- 10 years old) (Edward 2015). Normally, the blood oxygen saturation is 95%- 100%, but the patient got below 90% oxygen. There must not be able to take up the oxygen for inhaling and carbon dioxide for exhaling. In addition, the lungs in ARDS also affect to brain functions that the patient becomes confused and disoriented. In this conditions, concentrating ability are impaired and it also lost awareness of time and place because blood flow significantly reduce and the ability of oxygen absorption is also limited. In this case, the girl administrated of chlorpheniramine maleate which had some of the side effects such as drowsiness, dizziness, or headache. Moreover, certain human disorders are attributed to the activity of the immune system that is commonly known as hypersensitivities.

Both the heart and blood vessels are sensitive to cause vasodilatation in SIRS that act on histamine H1-receptors of dilation in blood vessels. In hypovolemia, tachycardia is initiated as a response in acting on H2- receptors where the blood volume decreases (Benly 2015).When the patient suffers around 124 beats per minute in heart rate and the vasoconstriction decrease which is moderate tachycardia or known as stage 3 of hypovolemic shock. As a result, the patients exhibited a weak peripheral pulse and an unrecordable blood pressure because the ventricles do not have enough time to fill with blood before heart contracts.

In systemic inflammatory response syndrome (SIRS), organ dysfunction and high- risk factors for multiple organ failures influent renal failure. The circulatory dysfunction of acute renal failure is involved both vascular and tubular factor that reduce in renal blood flow with falling oxygen and substrate delivery to the tubule cells (Robert et al. 2004). On the other hand, the creatinine will be released by the muscle cells and transported to the kidneys to be excreted from the body in urine. The kidney failure causes high urinary creatinine level and obstructions within the urinary tract.

Base on all the symptoms, the girl is immediate hypersensitivities, which is severe response to an antigen. Sensitization to an allergen during the initial exposure leads to the production of large immunoglobulin E (IgE) which is mediated release of histamine and other mediators from mast cells and basophils (Frederic et al. 2015). Moreover, the patient used two kinds of drugs: chlorpheniramine maleate and dexamethasone, which did not work with patient’s symptoms. Chlorpheniramine maleate is the most widely used of the classical antihistamine that used in allergic reactions. And, dexamethasone is investigated that the effect of glucocorticoids and blocked a natural chemical during an allergic rejection. However, hypersensitivity is a contraindication in both dexamethasone and chlorpheniramine maleate, so the patient should not take these when she has serious symptoms (TabletWise).

Basically, there is no cure for hypersensitivity disease but the treatment strategy is controlling the symptom. Although type I hypersensitivity reactions can cause significantly inconvenience in terms of their signs and symptoms. However, the most important medication has been shown to use along with emergency medical treatment of hypersensitivity that is epinephrine (Becky 2015). Epinephrine is in a class of medications called α- and β-adrenergic agonists which it works by relaxing the muscles in the airways and tightening the blood vessels. Normally, it is injected at the first sign of a serious reaction subcutaneously (under the skin) or intramuscularly (into the muscle). It should inject when patient is suspected about some serious signs of allergic reaction include itching, swelling, skin redness, fast heart beat, weak pulse, confusion, and losing control of urine (Epinephrine Injection).

References:

Alberts, B., Johnson, A., Lewis, J., et al. (2002) ‘Innate Immunity’. in Molecular Biology of the Cell. 4th edition. [online] available from < https://www.ncbi.nlm.nih.gov/books/NBK26846/ > [22 March 2016]

Benly, P. (2015) ‘Role of Histamine in Acute Inflammation’ Journal of Pharmaceutical Sciences and Research [online] avalible from <http://www.jpsr.pharmainfo.in/Documents/Volumes/vol7Issue06/jpsr07061526.pdf > [22 March 2016]

Becky, B. (2015) ‘Immediate Hypersensitivity Reactions Treatment & Management’. Medscape [online] available from <http://emedicine.medscape.com/article/136217-treatment > [22 March 2016]

Carl, A., and Max, V. (2016) ‘Wasp Stings: Background, Pathophysiology, Epidemiology’. Medscape.com. [online] available from < http://emedicine.medscape.com/article/169324-overview#a6 > [22 March 2016]

Edward, C. (2015) ‘Normal Vital Signs’ Medscape [online] available from < http://emedicine.medscape.com/article/2172054-overview > [22 March 2016]

Innate immunity (2014) KhanAcademy [online] available from < https://www.khanacademy.org/test-prep/mcat/organ-systems/the-immune-system/a/innate-immunity > [22 March 2016]

Janet, M., Mark, J., Yen, C., Antonio, B., Karim, B., Elizabeth, J., Leo, K., Paul, K., Richard, J. (2014) ‘The systemic immune response to trauma: an overview of pathophysiology and treatment’. The Lancet [online] available from < http://thelancet.com/journals/lancet/article/PIIS0140-6736(14)60687-5/fulltext > [22 March 2016]

Zhang, J and An, J. (2009) ‘Cytokines, Inflammation and Pain’. HHS Public Access [online] available from < https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2785020/ > [22 March 2016]