MUDr. Dana Maňasková


Vyhledávání na medicinman.cz
 

Deficit MBL

Meření

  • Crucial role of the MBL in the innate immune response during the last years, several studies focused on the association between MBL expression and/or concentrations in the body fluids and the clinical presentation. Likewise to proteins of the acute phase of inflammation, MBL blood levels increase in response to infections. Healthy adult individuals usually have MBL concentrations above 1000 ng/mL, and these levels seem to be not affected by the age, circadian cycle, and physical exercise. During inflammation, MBL levels increase within the 3-4-fold compared to the baseline level [64]. MBL deficiency in adults has been defined as plasmatic concentrations lower than 500 ng/mL or as an MBL function below 0.2 U/µLC4 deposition [65]. MBL levels may rise under stress to sufficient levels, in individuals who are usually deficient. A positive acute phase response was generally observed in individuals with wild-type MBL2 genes [64].
  • www.ncbi.nlm.nih.gov/pmc/articles/PMC5299167/
  • Calcium-dependent lectin involved in innate immune defense (PubMed:35102342).
Binds mannose, fucose and N-acetylglucosamine on different microorganisms and activates the lectin complement pathway. Binds to late apoptotic cells, as well as to apoptotic blebs and to necrotic cells, but not to early apoptotic cells, facilitating their uptake by macrophages. May bind DNA. Upon SARS coronavirus-2/SARS-CoV-2 infection, activates the complement lectin pathway which leads to the inhibition SARS-CoV-2 infection and a reduction of the induced inflammatory response
PubMed:35102342

  • MBL belongs to the group of the so-called “pattern recognition molecules” [16] that mediate the precocious activation of the immune response. MBL is produced by the liver [15, 17–19] and released in the serum under stress conditions [20, 21] as a calcium-dependent acute phase protein. Significantly increased circulating levels have been reported in response to infections. During inflammatory conditions MBL can also leave the blood stream due to vascular leakage and can be detected in the mucus of the middle ear, in upper airway secretions, in inflamed synovial fluid, and in the normal amnion fluid [22, 23]. MBL activates macrophages [24], enhances phagocytosis [25, 26], and plays a role in complement activation by inducing the antibody-independent lectin pathway [1, 13, 16, 27–31]. In particular, MBL, in cooperation with three MBL-associated serine proteases (MASPs 1, 2, and 3), is able to initiate the lectin pathway of complement activation, the release of cytokines, and coagulation factors. A single MASP entity was initially identified and characterized as a protease with the ability to cleave complement proteins C4, C2, and C3 [31, 32]. MASP was indeed a mixture of two related but distinct proteases, MASP-1 and MASP-2 [30]. A third protease, MASP-3, is also shown to be associated with MBL [33]. It is generally believed that MASP-2 is the initiator of the lectin-complement pathway, while the role of the other MASPs is still uncertain [34]. MASPs additionally form active complexes with Ficolin-1 (M-Ficolin), Ficolin-2 (L-Ficolin), and Ficolin-3 (H-Ficolin), which are also defence collagens
  • In the case of tissue damage after ischemia-reperfusion, MBL rapidly deposits on target cells and forms an IgM-MBL complex as soon as a specific autoreactive IgM binds to exposed tissue antigens and triggers the downstream complement activation in the acute phase, enhancing the cleavage of C3 [38]. Small amounts of MBL are also produced in organs other than the liver such as brain [39], kidney [40, 41], spleen [42], tonsil [43], thymus, small intestine [44], testis [42, 44], ovary [41], and vagina [45], suggesting that local expression of MBL may be relevant in local immune defence.
  • The genetic variability of both the promoter and the exon domains of MBL gene influences the subsequent stability and serum concentrations of the functionally active protein, leading to defect in opsonization and susceptibility to infections

Potraty

  • Inadequate Pathogen Clearance: MBL plays a role in recognizing and binding to certain pathogens, facilitating their clearance from the body. It is speculated that MBL deficiency may lead to impaired pathogen clearance, potentially allowing certain infections to persist or cause inflammation in the reproductive system. Persistent infections or inflammation in the uterus could potentially increase the risk of miscarriage.

Immunomodulation and Tissue Remodeling: MBL is involved in immune regulation and tissue remodeling processes. It has been suggested that MBL deficiency may affect the delicate balance of immune responses and tissue remodeling in the uterus during pregnancy. Alterations in these processes could potentially contribute to an increased risk of miscarriage.

Association with Other Genetic Factors: MBL deficiency may occur alongside other genetic factors or variations that could contribute to miscarriage risk. Studies have suggested that certain combinations of MBL gene variants and other genetic factors may be associated with an increased risk of miscarriage, but the mechanisms involved are still not fully understood.

Prophylactic Antibiotics: In some cases, prophylactic antibiotics may be prescribed to prevent or treat infections that could pose a risk to pregnancy. Antibiotics are typically chosen based on the specific pathogens that are commonly associated with MBL deficiency and tailored to the individual's situation. The decision to use antibiotics should be made in consultation with your healthcare provider.

Immune-modulating Therapies: Some research suggests that immune-modulating therapies, such as intravenous immunoglobulin (IVIG) or other immunomodulatory agents, may be beneficial in certain cases of recurrent miscarriage associated with immune factors, including MBL deficiency. These therapies aim to modulate the immune response and create a more favorable environment for pregnancy. However, the use of these treatments requires careful consideration and should be guided by a specialist.
Supportive Care: Maintaining a healthy lifestyle, including a balanced diet, regular exercise, sufficient rest, stress management, and avoiding harmful substances, is crucial for supporting a healthy pregnancy. Additionally, emotional support through counseling or support groups can help manage the stress and anxiety that may arise from concerns about pregnancy outcomes.

Prophylactic Antibiotics: In some cases, prophylactic antibiotics may be considered to prevent or treat infections that could pose a risk to pregnancy. The choice of antibiotics would depend on the specific pathogens associated with MBL deficiency. This decision should be made in consultation with your healthcare provider.

Immunomodulatory Therapies: Immune-modulating therapies, such as intravenous immunoglobulin (IVIG), have been explored in certain cases of recurrent miscarriage associated with immune factors, including MBL deficiency. These therapies aim to modulate the immune response and create a more favorable environment for pregnancy. However, the use of such therapies requires careful consideration, and their efficacy and safety in the context of MBL deficiency are still being studied.

Folic Acid Supplementation: Folic acid is commonly recommended for all women during pregnancy to reduce the risk of neural tube defects in the developing fetus. It is advisable to take a prenatal vitamin containing folic acid as per your healthcare provider's guidance.

Blood Thinners: In some cases, blood thinners (anticoagulants) may be prescribed if there are other risk factors for blood clotting disorders. MBL deficiency has been associated with an increased risk of thrombosis in certain studies. However, the decision to use blood thinners during pregnancy should be made on an individual basis and in consultation with a healthcare professional who can assess your specific risk factors.

Hormonal Support: In cases where MBL deficiency is associated with hormonal imbalances or abnormalities, hormonal support may be considered. This could involve the use of specific hormones, such as progesterone, to support the development and maintenance of pregnancy. However, the appropriateness and effectiveness of hormonal support would depend on the specific underlying factors and should be discussed with your healthcare provider.

Individualized Care: Given the complex nature of MBL deficiency and its potential impact on pregnancy, it is crucial to receive individualized care from a healthcare professional experienced in managing high-risk pregnancies. They can tailor the management plan based on your specific circumstances, taking into account factors such as your medical history, genetic profile, and any associated risk factors.

Regular Monitoring and Follow-up: Regular monitoring throughout the pregnancy is important to assess the health of both the mother and the developing fetus. This may involve more frequent prenatal visits, ultrasounds, and laboratory tests to detect any potential complications early on and allow for timely interventions.

Genetic Testing and Counseling: Genetic testing may be recommended to assess for any underlying genetic factors that may be associated with MBL deficiency and potential pregnancy complications. Genetic counseling can help you understand the implications of these findings and make informed decisions regarding family planning and pregnancy management.

Strava

  • Mannose binding lectins (MBL)
  • A key molecule in our innate immune response
  • Contributes to host defense against coronaviruses such as SARS-CoV
  • Increased consumption of fruits and vegetables as an accessible and viable approach to minimizing COVID-19 infection risk.
    • Increasing consumption of plant lectins (e.g., eating fruits and vegetables) may reduce COVID-19 risks.
Multiple studies have shown that MBL deficiency increases susceptibility to infection, including influenza and SARS-CoV-1.2,5,6 MBL deficiency is a condition affecting the immune system resulting in low levels of MBL in blood sera that occurs in up to 30% of the population, depending on ethnicity.2,3 Innate MBL production is genetically determined where both over- or under- production can both be problematic for different reasons.2,3 There are 3 coding region single-nucleotide polymorphisms (SNPs) for MBL at codons 52, 54 and 57 affecting MBL production.2,3 The frequency of these SNPs varies among different ethnicities where the codon 54 variant is very common.6
  • As plant lectins exhibit anti-coronavirus properties of varying efficacy, it’s likely that plant MBL supplementation is a contributing factor towards COVID-19 risk and outcomes.17 Plant lectins are common in food and dietary intake can be significant.16,28 Many non-legume plant lectins, including MBL, maintain full biological activity after consumption as they are typically not inactivated by cooking, resist digestion, and enter the circulation intact.16,28,29
An example where an active lectin supplement may be demonstrating its anti-coronaviral properties is the Nictaba lectin from the tobacco plant (Nicotiana tabacum). Nictaba is a GlcNAc-specific agglutinin that is active against SARS-CoV-1, which exposes manyglycans enabling interference with virus entry and virus release.17 With the similarities between SARS-CoV-2 and SARS-CoV-1 in combination with Nictaba being the 4th most active lectin previously tested for SARS-CoV-1 (SI: >58.8), Nictaba may be potent against SARS-CoV-2.17 Nictaba lectin, supplemented through the use of tobacco products, could explain the counter-intuitive observation that smokers have a significantly reduced risk of infection, which is highly unusual for a respiratory disease.30–33 Though the risk of infection may be reduced by Nictaba, tobacco products cause other damage, including to the respiratory system, which demonstrably increases the severity of COVID-19.34
While tobacco products have clear disadvantages in increasing COVID-19 severity, their ability to reduce infection risk suggests plant lectin supplementation (e.g., consumption of fruits and vegetables) may be a viable approach to augmenting host MBL production and boosting innate immune system response to SARS-CoV-2. See Table 1. At a macro scale, existing differences in dietary MBL consumption is consistent with observed differences in outcomes between men and women. Women have been shown to eat more fruits and vegetables than men, which presumably confers additional protection and resistance to women.35–37 This is consistent with observations that men are at higher risk for worse outcomes and death from COVID-19 than women.38
  • Diet: Certain foods contain mannose or substances that can promote mannose-binding lectin activity. Consider incorporating the following into your diet:

Legumes: Lentils, peas, and beans are good sources of mannose.

Mushrooms: Some varieties of mushrooms, such as shiitake and maitake, have been reported to enhance immune function, potentially including mannose-binding lectin activity.

Aloe vera: This plant has been suggested to stimulate the immune system and may influence mannose-binding lectins.

Probiotics: Gut health plays a significant role in immune function. Some probiotic strains, such as Lactobacillus and Bifidobacterium, have been associated with enhanced immune responses, potentially including mannose-binding lectin activity. Incorporate probiotic-rich foods like yogurt, kefir, sauerkraut, or take probiotic supplements after consulting with a healthcare professional.
Medicinal herbs: Some herbs may have immunomodulatory effects and could potentially influence mannose-binding lectins. Examples include echinacea, astragalus, and ginseng. However, it's essential to consult with a healthcare professional or herbalist before using these herbs, as they can interact with medications or have contraindications.
Lifestyle factors: Maintaining a healthy lifestyle can generally support immune function. This includes regular exercise, sufficient sleep, stress reduction techniques, and avoiding smoking or excessive alcohol consumption.
  • If you're referring to other ways to stimulate mannose-binding lectins naturally, here are a few additional suggestions:

Beta-Glucans: Beta-glucans are polysaccharides found in certain foods like oats, barley, and mushrooms (e.g., Reishi and Turkey Tail). They have been shown to have immune-enhancing effects, potentially including the stimulation of mannose-binding lectins.

Vitamin C: Adequate vitamin C intake is important for a healthy immune system. It may help support the production and activity of mannose-binding lectins. Good food sources of vitamin C include citrus fruits, strawberries, kiwi, bell peppers, and broccoli.

Herbal Supplements: Some herbal supplements are believed to have immune-stimulating properties and may potentially influence mannose-binding lectin activity. Examples include elderberry, garlic, and olive leaf extract. However, it's important to consult with a healthcare professional before starting any new supplements.

Avoiding Excessive Sugar: Consuming excessive amounts of sugar may negatively affect immune function. High sugar intake can interfere with the proper functioning of mannose-binding lectins. It's advisable to limit your consumption of processed foods, sugary drinks, and desserts.

Remember that while these suggestions

Green Tea: Green tea contains compounds called catechins, which have been shown to have immune-modulating effects. Some studies suggest that green tea catechins may enhance mannose-binding lectin activity. Aim to consume 2-3 cups of green tea per day to reap its potential benefits.

Seaweed: Certain types of seaweed, such as kombu, wakame, and nori, are rich in fucoidan, a type of complex carbohydrate. Fucoidan has been reported to stimulate immune function, including the activity of mannose-binding lectins. Incorporate seaweed into your diet through sushi rolls, salads, or as a garnish.

Medicinal Mushrooms: In addition to their potential immune-enhancing properties mentioned earlier, medicinal mushrooms like reishi, cordyceps, and turkey tail are known to contain polysaccharides that can stimulate various aspects of the immune system, including mannose-binding lectins. These mushrooms can be consumed as extracts, powders, or in culinary preparations.

Zinc-Rich Foods: Adequate zinc intake is crucial for optimal immune function. Zinc deficiency can impair the production and activity of mannose-binding lectins. Include zinc-rich foods in your diet, such as oysters, beef, poultry, pumpkin seeds, and legumes.

Stress Reduction: Chronic stress can weaken the immune system, including the activity of mannose-binding lectins. Engage in stress-reducing activities like meditation, yoga, deep breathing exercises, or hobbies that help you relax and unwind.

Immunoglobulins and other immune-enhancing compounds, including factors that can stimulate mannose-binding lectins. Colostrum supplements are available in powder or capsule form.

Astragalus Root: Astragalus is an herb commonly used in traditional Chinese medicine. It is believed to have immune-stimulating properties and may support the activity of mannose-binding lectins. Astragalus root can be consumed as a tea or taken as a supplement.

Exercise: Regular moderate-intensity exercise has been shown to have immune-boosting effects. Engaging in physical activity can enhance overall immune function, potentially including the activity of mannose-binding lectins. Aim for at least 150 minutes of moderate-intensity exercise per week.

Cold Water Immersion: Cold water immersion, such as taking cold showers or ice baths, has been reported to have immune-modulating effects. It may help stimulate the immune system, including the production and activity of mannose-binding lectins. Start with shorter durations and gradually increase exposure over time.

Medicinal Herbs: Several other medicinal herbs and supplements may have immune-stimulating properties that can potentially impact mannose-binding lectins. Examples include echinacea, Andrographis paniculata, elderberry, and olive leaf extract. Consult with a healthcare professional or herbalist for appropriate dosages and guidance.

Please note that while these suggestions may have potential benefits, individual responses may vary. It's important to consult with a healthcare professional or qualified practitioner before making any significant changes

Varianty

Position(s) DescriptionNatural variant VAR_013294 24 in Chinese

Natural variant VAR_008543 52 in 0.05% of European and African populations; dbSNP:rs5030737
Natural variant VAR_004182 54 associated with low serum mannose-binding protein (MBP) concentrations and recurrent infections; dbSNP:rs1800450
Natural variant VAR_004183 57 associated with low serum mannose-binding protein (MBP) concentrations; associated with protection against tuberculosis caused by Mycobacterium africanum; dbSNP:rs1800451
Natural variant VAR_050119 214 in dbSNP:rs12260094
PolymorphismGenetic variations in MBL2 influence susceptibility to hepatitis B virus (HBV) infection [MIM:610424].Genetic variations in MBL2 may influence susceptibility to severe COVID-19 disease caused by SARS-CoV-2 virus infection.Genetic variations in MBL2 are responsible for mannose-binding protein deficiency [MIM:614372]. This condition is defined as MBL2 protein level of less than 100 ng/ml, is present in about 5% of people of European descent and in about 10% of sub-Saharan Africans. Most MBL2-deficient adults appear healthy, but low levels of MBL2 are associated with increased risk of infection in toddlers, in cancer patients undergoing chemotherapy, and in organ-transplant patients receiving immunosuppressive drugs, particularly recipients of liver transplants. There is an association between low levels of MBL2 and a defect of opsonization which results in susceptibility to frequent and chronic infections (PubMed:1675710).Functional MBL2 deficiency may be associated with protection against tuberculosis caused by Mycobacterium africanum but not by Mycobacterium tuberculosis, as observed in studies on Ghanaian patients with pulmonary tuberculosis (PubMed:21695215).
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Poslední aktualizace: 30. 9. 2024 0:46:52