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{{WBRQuestion
{{WBRQuestion
|QuestionAuthor=[[User:Gonzalo Romero|Gonzalo A. Romero, M.D.]] [mailto:gromero@wikidoc.org]
|QuestionAuthor= {{SSK}}(Reviewed by Serge Korjian)
|ExamType=USMLE Step 1
|ExamType=USMLE Step 1
|MainCategory=Embryology, Pathology
|MainCategory=Embryology, Pathology
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|MainCategory=Embryology, Pathology
|MainCategory=Embryology, Pathology
|SubCategory=Reproductive
|SubCategory=Reproductive
|MainCategory=Embryology, Pathology
|MainCategory=Embryology, Pathology
|MainCategory=Embryology, Pathology
|MainCategory=Embryology, Pathology
|MainCategory=Embryology, Pathology
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|MainCategory=Embryology, Pathology
|MainCategory=Embryology, Pathology
|SubCategory=Reproductive
|SubCategory=Reproductive
|Prompt=A 10-year-old male teenager is concerned because one of his testis is not in his scrotum. They live in rural Pennsylvania, where health care is not readily available. He tells his mother because sometimes it is embarrassing for him when taking a shower with his swim team peers. He patient finally convinces his mother to take him to the doctor, who is very distant from where they live.  The physician has a clinical suspicion just with the chief complaint.  This patient is at risk of developing which of the following if left untreated?
|Prompt=A 43-year-old man with history of chronic gastritis presents to the emergency department for several episodes of bloody emesis that started a few hours after his last meal. On admission, the patient is alert and oriented but complains of severe, continuous epigastric pain. His blood pressure is 90/62 mm Hg, heart rate is 130/min, and temperature is 36.7 ᵒC (98 ᵒF). After initial fluid resuscitation, the patient improves and his vitals stabilize. Gastroduodenoscopy reveals a 2.5 cm crusted ulcer in the duodenal bulb. The following day, the patient's hematocrit drops to 6.7 g/dL. He is typed and cross-matched to receives 2 units of red blood cells. Within 10 minutes of initiating the transfusion, the patient complains of generalized pruritus. Physical exam reveals a skin rash apparent mostly on the trunk and upper extremities (shown below). The transfusion is discontinued and vitals remain stable. The patient does not develop fever over the next 4 hours. Which of the following most likely etiology of the transfusion reaction in this patient?
|Explanation=This patient is presenting with [[cryptorchidism]], which is the abscence or undescend of one or both testis into the scrotum.
'''Embryology:''' the testes remain high in the abdomen until the 7th month of gestation, when they move from the abdomen through the inguinal canals into the two sides of the scrotum. It has been proposed that movement occurs in two phases, under control of somewhat different factors. The first phase, movement across the abdomen to the entrance of the inguinal canal appears controlled (or at least greatly influenced) by anti-müllerian hormone (AMH). The second phase, in which the testes move through the inguinal canal into the scrotum, is dependent on androgens (most importantly testosterone). In rodents, androgens induce the genitofemoral nerve to release calcitonin gene-related peptide (CGRP), which produces rhythmic contractions of the gubernaculum, a ligament which connects the testis to the scrotum, but a similar mechanism has not been demonstrated in humans. Maldevelopment of the gubernaculum, or deficiency or insensitivity to either AMH or androgen therefore can prevent the testes from descending into the scrotum.
<br>
'''Physiologically''' it impairs spermatogenesis, because sperm cells develop at temperatures below 37C.  They have normal testosterone levels, because Leydig cells are not affected by high temperatures, as supposed to the Sertoli cells which are affected. Lab tests reveal Prematurity decreased inhibin (by Sertoli cells), increased FSH and normal LH and testosterone.  It is seen more frequent in premature infants.
<br>
'''Cancer risk:''' about 1 in 500 men born with one or both testes undescended develop testicular cancer (seminoma), roughly a 4 to 40 fold increased risk. The risk is higher for intra-abdominal testes and lower for inguinal testes. The New England Journal of Medicine published in 2007 that orchidopexy performed before puberty resulted in a significantly reduced risk of testicular cancer than if done after puberty. (See https://www.ncbi.nlm.nih.gov/pubmed/17476009)
<font color="MediumBlue"><font size="4">
<br>
<br>
'''Educational Objective:''' </font></font>
[[File:WBR0508.jpg|600px]]
# Cryptorchidism (undescended testis) is associated with an increased risk of developing testicular cancer, specifically germ cell tumors (seminoma).
|Explanation=Acute transfusion reactions classically present during or within 24 hours of a blood transfusion. They require instant recognition and intervention to prevent further injury. The most severe form of transfusion reaction is ABO mismatch causing hemolysis and possibly disseminated intravascular coagulopathy. More benign forms include non-hemolytic febrile reactions and non-anaphylactic allergic reactions. Simple allergic transfusion reactions, such as in this patient, usually present with isolated urticaria (hives) and pruritus similar to most food and drug allergies. These reactions are good examples of type I hypersensitivity reactions. Allergic transfusion reactions are IgE-mediated reactions to plasma protein products and antibodies in the donor blood. These proteins activate IgE-primed mast cell that release histamine and other vasoactive mediators. In patients with allergic transfusion reactions, the transfusion can be continued (unlike this patient), and symptomatic treatment with rapid-acting antihistamines should be initiated. To prevent recurrence, pretreatment with antihistamines may be warranted in these patients. A more severe form of allergic transfusion reaction is anaphylaxis secondary to anti-IgA immunoglobulin found in recipients who are natively IgA deficient. These patients require washed or IgA-deficient blood products. In case of suspected anaphylaxis, immediate discontinuation of the transfusion and epinephrine administration is recommended.
'''References:''' First Aid 2012 reproductive chapter, page 575
[[File:Transfusion_reactions.png|1000px]]
|AnswerA=Germ cell tumor
|AnswerA=Plasma proteins in transfused blood
|AnswerAExp=<font color="Green">'''Correct.'''</font> Cryptorchidism increases the risk of developing [[germ cell tumors]].  Germ cell tumors represent 95 % of all testicular tumors, are frequently malignant.
|AnswerAExp=Allergic transfusion reactions are due to activation of IgE-primed mast cells by plasma proteins found in the donor transfused blood.
|AnswerB=Inguinal hernia
|AnswerB=Cytokines from leukocytes in donor blood
|AnswerBExp=<font color="red">'''Incorrect.'''</font> A [[hernia]] is a protrusion of peritoneum through an opening, frequently due to an area of weakness weakness.
|AnswerBExp=One of the mechanisms of non-hemolytic febrile transfusion reactions involves a reaction to cytokines produced by leukocytes in the donor blood. These cytokines do not invoke an allergic type I hypersensitivity reaction.
|AnswerC=Varicocele
|AnswerC=Host antibodies against antigens on donor RBCs
|AnswerCExp=<font color="red">'''Incorrect.'''</font> [[Varicocele]] are dilated veins in the pampiniform plexus due to increased venous pressure. It is the most common cause of scrotal enlargement in adult males.  Frequently presents on the ; most  left side due to the increased resistance to flow from left spermatic vein drainage into the left renal vein. Long term it can produce infertility due to increased temperature. On physical examination it has a "bag of worms" appearance. It is diagnosed by ultrasound.
|AnswerCExp=Transfusion ABO incompatibility is relatively uncommon, but still occurs due to medical errors. Hemolytic transfusion reactions due to ABO mismatch are caused by host antibodies against the main (A/B) antigens on donor RBCs.
|AnswerD=Leydig cell tumor
|AnswerD=Host antibodies against donor MHC antigens
|AnswerDExp=<font color="red">'''Incorrect.'''</font> [[Leydig cell tumor]] They frequently secrete androgen resulting in gynecomastia in men, precocious puberty in boys. Macroscopically it presents as a golden brown colored tumor, and histologically it contains Reinke crystals.
|AnswerDExp=Another main mechanism of non-hemolytic febrile transfusion reactions is host antibodies against donor MHC antigens found on leukocytes. This mechanism does not invoke an allergic reaction. It can be preveented by using leukocyte filters or blood irradiation.
|AnswerE=Sertoli cell tumor
|AnswerE=Host antibodies against donor IgA molecules
|AnswerEExp=<font color="red">'''Incorrect.'''</font> [[Sertoli Cell Tumor]] such as androblastoma arise from the sex cord stroma
|AnswerEExp=The main etiology of anaphylaxis in patients undergoing transfusions is host antibodies against donor IgA molecules, particularly in patients who are IgA-deficient. These patients might have urticaria, but their symptoms are much more severe, and if untreated progress to cardiovascular collapse.
|EducationalObjectives=Allergic transfusion reactions usually present with urticaria and pruritus similar to most food and drug allergies. These reactions are good examples of type I hypersensitivity reactions. Allergic transfusion reactions are IgE-mediated reactions to plasma protein products and antibodies in the donor blood.
|References=Squires JE. Risks of transfusion. South Med J. 2011;104(11):762-9.
|RightAnswer=A
|RightAnswer=A
|WBRKeyword=cryptorchidism
|WBRKeyword=transfusion, transfusion reactions, IgA, non-hemolytic febrile transfusion reaction, NHFTR, hypersensitivity reactions, hypersensitivity, blood transfusion
|Approved=Yes
|Approved=Yes
}}
}}

Latest revision as of 00:48, 28 October 2020
Author [[PageAuthor::Serge Korjian M.D.(Reviewed by Serge Korjian)]]
Exam Type ExamType::USMLE Step 1
Main Category MainCategory::Embryology, MainCategory::Pathology
Sub Category SubCategory::Reproductive
Prompt [[Prompt::A 43-year-old man with history of chronic gastritis presents to the emergency department for several episodes of bloody emesis that started a few hours after his last meal. On admission, the patient is alert and oriented but complains of severe, continuous epigastric pain. His blood pressure is 90/62 mm Hg, heart rate is 130/min, and temperature is 36.7 ᵒC (98 ᵒF). After initial fluid resuscitation, the patient improves and his vitals stabilize. Gastroduodenoscopy reveals a 2.5 cm crusted ulcer in the duodenal bulb. The following day, the patient's hematocrit drops to 6.7 g/dL. He is typed and cross-matched to receives 2 units of red blood cells. Within 10 minutes of initiating the transfusion, the patient complains of generalized pruritus. Physical exam reveals a skin rash apparent mostly on the trunk and upper extremities (shown below). The transfusion is discontinued and vitals remain stable. The patient does not develop fever over the next 4 hours. Which of the following most likely etiology of the transfusion reaction in this patient?


]]

Answer A AnswerA::Plasma proteins in transfused blood
Answer A Explanation AnswerAExp::Allergic transfusion reactions are due to activation of IgE-primed mast cells by plasma proteins found in the donor transfused blood.
Answer B AnswerB::Cytokines from leukocytes in donor blood
Answer B Explanation AnswerBExp::One of the mechanisms of non-hemolytic febrile transfusion reactions involves a reaction to cytokines produced by leukocytes in the donor blood. These cytokines do not invoke an allergic type I hypersensitivity reaction.
Answer C AnswerC::Host antibodies against antigens on donor RBCs
Answer C Explanation AnswerCExp::Transfusion ABO incompatibility is relatively uncommon, but still occurs due to medical errors. Hemolytic transfusion reactions due to ABO mismatch are caused by host antibodies against the main (A/B) antigens on donor RBCs.
Answer D AnswerD::Host antibodies against donor MHC antigens
Answer D Explanation [[AnswerDExp::Another main mechanism of non-hemolytic febrile transfusion reactions is host antibodies against donor MHC antigens found on leukocytes. This mechanism does not invoke an allergic reaction. It can be preveented by using leukocyte filters or blood irradiation.]]
Answer E AnswerE::Host antibodies against donor IgA molecules
Answer E Explanation [[AnswerEExp::The main etiology of anaphylaxis in patients undergoing transfusions is host antibodies against donor IgA molecules, particularly in patients who are IgA-deficient. These patients might have urticaria, but their symptoms are much more severe, and if untreated progress to cardiovascular collapse.]]
Right Answer RightAnswer::A
Explanation [[Explanation::Acute transfusion reactions classically present during or within 24 hours of a blood transfusion. They require instant recognition and intervention to prevent further injury. The most severe form of transfusion reaction is ABO mismatch causing hemolysis and possibly disseminated intravascular coagulopathy. More benign forms include non-hemolytic febrile reactions and non-anaphylactic allergic reactions. Simple allergic transfusion reactions, such as in this patient, usually present with isolated urticaria (hives) and pruritus similar to most food and drug allergies. These reactions are good examples of type I hypersensitivity reactions. Allergic transfusion reactions are IgE-mediated reactions to plasma protein products and antibodies in the donor blood. These proteins activate IgE-primed mast cell that release histamine and other vasoactive mediators. In patients with allergic transfusion reactions, the transfusion can be continued (unlike this patient), and symptomatic treatment with rapid-acting antihistamines should be initiated. To prevent recurrence, pretreatment with antihistamines may be warranted in these patients. A more severe form of allergic transfusion reaction is anaphylaxis secondary to anti-IgA immunoglobulin found in recipients who are natively IgA deficient. These patients require washed or IgA-deficient blood products. In case of suspected anaphylaxis, immediate discontinuation of the transfusion and epinephrine administration is recommended.


Educational Objective: Allergic transfusion reactions usually present with urticaria and pruritus similar to most food and drug allergies. These reactions are good examples of type I hypersensitivity reactions. Allergic transfusion reactions are IgE-mediated reactions to plasma protein products and antibodies in the donor blood.
References: Squires JE. Risks of transfusion. South Med J. 2011;104(11):762-9.]]

Approved Approved::Yes
Keyword WBRKeyword::transfusion, WBRKeyword::transfusion reactions, WBRKeyword::IgA, WBRKeyword::non-hemolytic febrile transfusion reaction, WBRKeyword::NHFTR, WBRKeyword::hypersensitivity reactions, WBRKeyword::hypersensitivity, WBRKeyword::blood transfusion
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