Transfusion-Related Acute Lung Injury (TRALI) is characterized by non-cardiogenic pulmonary edema. The "Two-Hit" hypothesis suggests the second hit is the transfusion of biological response modifiers (lipids/antibodies) that activate:

Differentiation between TRALI and Transfusion Associated Circulatory Overload (TACO) is critical for management. Which biomarker is elevated in TACO but typically normal in TRALI?

Post-Transfusion Purpura (PTP) is a delayed reaction occurring 7-10 days post-transfusion. The thrombocytopenia is profound and affects:

A patient experiences a 1.5°C rise in temperature during a red cell transfusion with no other symptoms. The DAT is negative. The pathophysiology involves:

Which organism is the most common cause of fatal transfusion-transmitted bacterial sepsis in the United States, typically associated with Platelet Concentrates?

Irradiation of blood components is the only proven method to prevent Transfusion-Associated Graft-Versus-Host Disease (TA-GVHD). The mechanism of TA-GVHD involves:

In a Delayed Hemolytic Transfusion Reaction (DHTR), the DAT is often mixed-field positive. If the antibody screen was negative pre-transfusion, this is an anamnestic response. Which blood group antibodies are most notorious for dropping below detectable levels?

Citrate toxicity (hypocalcemia) is a risk in massive transfusion and apheresis. The earliest sign of citrate toxicity in a conscious patient is:

A patient has an anaphylactic reaction to FFP. Laboratory investigation reveals the patient is IgA deficient (< 0.05 mg/dL). Future transfusions for this patient should be:

Which of the following creates the highest risk for Transfusion-Related Immunomodulation (TRIM), potentially leading to increased post-operative infection or cancer recurrence?

Iron overload (Transfusion Hemosiderosis) becomes a clinical concern (requiring chelation therapy) typically after approximately how many units of Red Blood Cells have been transfused chronically?

A "Hypotensive Transfusion Reaction" is distinct from anaphylaxis because:

Hemolysis in a unit of packed red blood cells before transfusion can be caused by all of the following EXCEPT:

The primary mitigation strategy currently used to reduce the incidence of TRALI is:

In ABO HDFN, the mother is predominantly Group O and the baby is Group A or B. Why is ABO HDFN rarely seen in Group A mothers carrying Group B fetuses?

Which antibody causes HDFN characterized by severe anemia with relatively low levels of bilirubin (reticulocytopenia), due to suppression of erythroid progenitors (CFU-E)?

The "Lilie" or "Lui" Freeze-Thaw elution technique is most effective for recovering which type of antibody from cord blood red cells?

What is the critical titer (standard threshold) for Anti-D that generally prompts invasive monitoring (MCA-PSV) or amniocentesis?

Middle Cerebral Artery Peak Systolic Velocity (MCA-PSV) is measured via Doppler ultrasound to assess:

Calculate the RhIg dosage: A Kleihauer-Betke stain reveals 1.6% fetal cells in a maternal circulation of 5000 mL. Formula: (Fetal % x 5000) / 30. Round, then add 1.

A "Blocked D" result in a newborn (Mother Rh-, Baby Rh+) manifests as:

Why is Rh Immune Globulin (RhIg) generally not effective in preventing sensitization to the D-antigen if administered after the mother has already formed Anti-D?

Which IgG subclass is most efficient at crossing the placenta via the FcRn receptor, appearing in fetal circulation as early as 12 weeks?

Exchange transfusion is preferred over simple transfusion in severe HDFN because it accomplishes all of the following EXCEPT:

Which phenotype would make a woman a candidate for RhIg administration?

Intrauterine Transfusion (IUT) typically uses blood that is:

A Rosette Test is a qualitative screen for Feto-Maternal Hemorrhage (FMH). It detects FMH of approximately:

Which rare antibody is associated with severe HDFN and requires screening of the father's cells because the antigen is high-prevalence (meaning compatible blood is hard to find)?

Phototherapy (UV light) converts unconjugated bilirubin into _______ , which can be excreted without conjugation.

The gene AIRE (Autoimmune Regulator) is essential for:

A mutation in the FOXP3 gene leads to a lack of Regulatory T cells (Tregs) and causes which severe autoimmune syndrome?

Th1 cells primarily secrete _______ and support cell-mediated immunity (macrophage activation), while Th2 cells secrete _______ and support humoral immunity (antibody production).

"Epitope Spreading" in autoimmunity refers to:

Type II Hypersensitivity is mediated by:

Which checkpoint receptor on T-cells functions as a "brake" on the immune system by competing with CD28 for B7 (CD80/86) binding, typically inducing anergy?

"Molecular Mimicry" suggests autoimmunity arises when:

The "Hygiene Hypothesis" proposes that a lack of early childhood exposure to infectious agents and symbiotic microorganisms increases susceptibility to:

Type IV Hypersensitivity (Delayed Type) is the primary mechanism behind:

Which cytokine is considered predominantly "anti-inflammatory" and is crucial for Treg function?

Chronic Granulomatous Disease (CGD) is a defect in phagocyte function (NADPH oxidase), but identifying it often relies on assessing the failure of the "Respiratory Burst." This is most accurately measured by:

Natural Killer (NK) cells are regulated by a "Balance of Signals." They are activated to kill a target cell if:

Rheumatoid Factor (RF) is an autoantibody (usually IgM) directed against:

Which complement deficiency is most strongly associated with the development of Systemic Lupus Erythematosus (SLE) due to the inability to clear immune complexes?

"Peripheral Tolerance" mechanisms include all of the following EXCEPT:

The Arthus Reaction (localized vasculitis/necrosis at injection site) is a classic example of:

T-cell receptor (TCR) diversity is generated by V(D)J recombination. However, affinity maturation (improving the binding strength) occurs in:

Which molecule serves as the "co-stimulatory signal" (Signal 2) on the Antigen Presenting Cell (APC) that must bind to CD28 on the T-cell for activation?

Superantigens (like Staph enterotoxins) cause massive non-specific T-cell activation by:

In the context of tumor immunology, "Immunoediting" consists of three phases: Elimination, Equilibrium, and:

ACE inhibitors prevent the breakdown of Bradykinin. Negatively charged filters/surfaces in apheresis or blood tubing can activate the contact system, generating Bradykinin, leading to hypotension.

TRALI: First hit primes neutrophils; Second hit activates them to damage lung endothelium.

BNP is a marker of cardiac strain/volume overload. It is high in TACO, normal in TRALI.

PTP involves destruction of both due to antigen-negative platelets producing antibody that destroys antigen-positive donor platelets and somehow bystander autologous platelets.

Febrile Non-Hemolytic Reaction is caused by accumulated cytokines or host Abs against donor leukocytes.

While S. aureus is pathogenic, skin flora S. epidermidis is the most frequent contaminant; Yersinia is rare but associated with RBCs. If the question asks for the most common cause of sepsis stats, skin flora dominates platelets.

TA-GVHD is mediated by donor T-cells attacking the host.

Kidd antibodies are notorious for disappearing and causing Delayed HTRs.

Perioral paresthesia is the classic first sign of hypocalcemia.

Must avoid IgA. Washed cells remove plasma; IgA deficient donors are ideal.

Leukocytes in transfusions are immunosuppressive.

Typically 50-100 units or ~20-50 transfusions leads to significant iron burden.

Hypotensive reactions mediated by bradykinin stop quickly when the infusion stops; Anaphylaxis persists/progresses.

Normal saline is the only compatible fluid. Dextrose causes clumping/lysis; Water causes lysis.

TRALI mitigation involves excluding multiparous female plasma donors to reduce HLA antibody risk.

Group O moms make IgG Anti-A,B which crosses placenta. Group A moms make IgM Anti-B which does not.

Kell antibodies suppress erythropoiesis at the stem cell level, causing anemia without massive hemolysis/bilirubin.

Lui Freeze-Thaw is optimal for ABO antibodies; Acid elution is for Rh/Kell/Duffy.

Critical titer is usually 16 or 32.

Anemia increases blood velocity. MCA-PSV measures this to predict anemia severity.

Calc: 1.6×50=80 mL. 80/30=2.6. Round up to 3. Add safety = 4 vials.

Maternal Anti-D coats the baby's D+ cells. The anti-D reagent cannot bind [blocked]. DAT is positive.

RhIg is preventative. It interferes with primary response. Once memory cells exist, it is ineffective.

IgG1 is the most efficient transporter.

Exchange removes bilirubin, antibody, and coated cells. It does not stimulate marrow; IUT suppresses marrow.

RhIg protects against D sensitization. Anti-K presence does not prevent Anti-D formation; she still needs RhIg.

27. Standard IUT unit specs: Fresh, O-, CMV-, Irr, Hct high to minimize volume.

Rosette detects >10mL. It is a screen only.

Anti-Vel and Anti-Tja are directed against high-prevalence antigens, making blood very hard to find.

Photo-isomers/Lumirubin are water soluble.

AIRE allows thymic cells to display "self" antigens like insulin/thyroid to test T-cells.

A patient with Sickle Cell Disease has been chronically transfused and has developed multiple alloantibodies. They now present with a "Hyperhemolytic" crisis where their hemoglobin drops lower than the pre-transfusion level after receiving antigen-matched blood. The mechanism is believed to be:

Transfusion-Associated Graft-Versus-Host Disease (TA-GVHD) is almost universally fatal. The diagnosis is confirmed by:

Which of the following blood products carries the highest risk of transmitting Babesia microti?

A patient receiving a unit of Red Blood Cells develops a fever of 39.5°C, rigors, and hypotension after only 50 mL is infused. The unit looks slightly darker than normal. The Gram stain of the unit reveals Gram-negative rods. The most likely organism is:

Regarding Transfusion-Related Acute Lung Injury (TRALI), the "Gold Standard" for mitigation implemented by blood centers is:

Allergic reactions (urticaria) are caused by Type I hypersensitivity to plasma proteins. If a patient has repeated severe allergic reactions (but is not IgA deficient), the best component modification is:

In a Massive Transfusion (defined as >10 units/24 hrs), which coagulation factor becomes depleted first, dropping below hemostatic levels (100 mg/dL), often requiring cryoprecipitate replacement?

Post-Transfusion Purpura (PTP) is treated primarily with:

Which biomarker ratio is useful in distinguishing TRALI (low ratio) from TACO (high ratio) when analyzing pulmonary edema fluid vs serum?

Delayed serologic transfusion reactions (DSTR) are defined as:

The "Storage Lesion" of RBCs results in the release of bioactive lipids and cytokines. This accumulation is most dangerous in massive transfusion for neonates because it can cause:

A patient experiences dyspnea and hypoxia during transfusion. The BNP level is >1200 pg/mL (significantly elevated over baseline) and the central venous pressure (CVP) is high. This confirms:

Pre-medication with Acetaminophen and Diphenhydramine is often practiced but specifically prevents:

Iron chelation therapy (e.g., Deferasirox) is indicated in thalassemia or sickle cell patients when the Serum Ferritin consistently exceeds:

Patients with Paroxysmal Nocturnal Hemoglobinuria (PNH) should receive which type of blood products to prevent complement activation and hemolysis?

Which fetal antigen is poorly developed at birth, often resulting in a Negative or Weakly Positive DAT in cases of HDFN involving this system?

The primary danger of High-Titer maternal Anti-D to the fetus is:

Which of the following is a common complication associated with massive blood transfusions, particularly due to the citrate used as an anticoagulant?

What is the primary mechanism by which Anti-D immunoglobulin prevents Rh sensitization in Rh-negative mothers?