Description

Microbiology is the study of microscopic single and multi-celled organisms. A wide range of microorganisms are capable of bringing about infectious diseases. Immunology is the study of the immune system in a variety of organisms. Microbiology and immunology go hand in hand because disease causing microbes elicit an immune response and influence the immune system during infection. Dengue fever, intestinal sickness, leishmaniasis, and tuberculosis are only a couple of the illnesses that scientists concentrate on utilizing bacterial, eukaryotic, and viral microorganisms and infections. They are also interested in learning how the host immune system reacts to infection. The molecular characterization of significant key functions and pathways in T-cell biology has been made possible by the investigation of human T-cell PIDs with Mendelian inheritance. T-cell PIDs typically manifest as deficiencies of both T and B cells. In the first year of life, Severe Combined Immunodeficiencies (SCID) are characterized by a complete lack of T-cell development and, in some instances, a developmental block in other lymphoid lineages. Hypomorphic mutations in typical SCID-associated genes or partial defects in T-cell development cause Combined Immunodeficiency (CID) syndromes, which manifest later in childhood as an increased susceptibility to infection frequently accompanied by disturbances in immune homeostasis, such as autoimmunity and an increased incidence of lymphoproliferation. The disclosure of transformations and portrayal of the cell changes that underlie lymphocyte deformities and safe dysregulation have prompted novel, explicit, fruitful treatments for serious infections which are frequently lethal whenever left untreated. Understanding the disease mechanisms of T-cell immunodeficiencies and improving the long-term outcomes of potentially curative treatments, such as gene therapy, have made impressive progress in recent years.

Therapy of Immunodeficiency

The patient's medical records were used to gather clinical and radiological data. The immunological characteristics were characterized using flow cytometry, with a particular focus on regulatory T cells. An inflammatory complication radiologically, clinically, and histologically compatible with GLILD developed during follow-up in a 16-year-old girl with Kabuki syndrome and a 12-year-old boy on immunoglobulin replacement therapy for a CVID-like humoral immunodeficiency. They needed treatment, so sirolimus was given to them. It worked well and didn't have any serious side effects. These two cases shed light on the underlying immune anomalies at the local and systemic levels that lead to the development of GLILD, including the possibility of T-cell involvement. When steroids don't work, combined chemotherapy is usually used to treat GLILD, but some people have had success with monotherapy. These are the only two GLILD patients who have been successfully treated with sirolimus to our knowledge. If impairment is demonstrated, further research into mTOR inhibitors as a more targeted treatment for GLILD may be necessary.

T-cells are one of the two primary types of lymphocytes (the other being B-cells), and their normal function is to assist with the human body's immunity. T-cell deficiency is a deficiency of T-cells that is caused by decreased function of individual T-cells. T-cell insufficiency typically presents as unusually severe common viral infections (such as respiratory syncytial virus and rotavirus), diarrhea, and eczematous rashes. Later symptoms of a T-cell deficiency include cachexia and failure to thrive. Immunodeficiency, also known as immunocompromisation, is a condition in which the body's immune system is unable to fight cancer and infectious diseases. Extrinsic factors that affect the patient's immune system are the primary cause of the majority of acquired (secondary) cases. Instances of these outward factors incorporate HIV contamination and natural variables, for example, nutrition. Immunocompromisation may likewise be because of hereditary illnesses/defects like SCID. In clinical settings, immunosuppression by certain medications, like steroids, can either be an unfriendly impact or the planned reason for the treatment. As an anti-rejection measure during organ transplant surgery and in patients with autoimmune diseases that cause an overactive immune system, this type of treatment is used. Primary immunodeficiency, also known as intrinsic immune deficiency, is a condition that affects some people from birth. An individual who suffers from any kind of immunodeficiency is considered to be immunocompromised. In addition to normal infections that could affect anyone, an immunocompromised person may be particularly susceptible to opportunistic infections. It also reduces cancer immunosurveillance, in which the immune system scans the body's cells and kills neoplastic ones. Due to the lack of protection provided by vaccines, they are also more susceptible to infectious diseases.

Common Variable Immunodeficiency

Numerous immunodeficiency syndromes exhibit autoimmunity like clinical and laboratory characteristics. Common Variable Immunodeficiency (CVID), in which multiple autoimmune diseases, such as inflammatory bowel disease, autoimmune thrombocytopenia, and autoimmune thyroid disease, are present, may be the cause of autoimmunity through perpetual immune system activation in these patients. Another example is the autosomal recessive primary immunodeficiency known as familial hemophagocytic, lymphohistiocytosis. These patients frequently exhibit rashes, lymph node enlargement, liver and spleen enlargement, and low blood levels of platelets, white blood cells, and red blood cells. Due to a lack of perforin, multiple unidentified viral infections are thought to be present. In X-Linked Agammaglobulinemia (XLA), numerous autoimmune diseases, including arthritis, autoimmune hemolytic anemia, scleroderma, and diabetes, are also present. Chronic Granulomatous Disease (CGD) also has chronic inflammation of the intestines and lungs as well as recurring bacterial and fungal infections. A decrease in neutrophils' production of Nicotinamide Adenine Dinucleotide Phosphate (NADPH) oxidase is the root cause of CGD. Midline granulomatous disease patients often have hypomorphic RAG mutations; an autoimmune condition that frequently affects people with NK/T cell lymphomas and granulomatosis with polyangiitis. Patients with Wiskott Aldrich Syndrome (WAS) also have lymphoma, eczema, autoimmune manifestations, and recurring bacterial infections. Autoimmunity and infections coexist in Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy (APECED) as well: Chronic mucocutaneous candidiasis and organ-specific autoimmune manifestations like hypoparathyroidism and adrenocortical failure are examples. Finally, IgA deficiency is occasionally linked to the onset of autoimmune and atopic conditions.