For each of these try to determine the disease and the underlying immune mechanisms responsible
Clicking the "diagnosis" button will give you the answer to the case and key identifying symptoms
CASE 1
While playing tennis on a warm day a young man felt a wasp on his arm and brushed it off, but still received a mild sting which he ignored. Ten minutes later he felt dizzy and began to itch under his arms and on his scalp. When he broke out in hives and felt a tightness in his chest, he headed for the hospital. On the way he felt cold and clammy and collapsed on the seat of the taxi. In the emergency room his pulse was barely detectable.
CASE 2
A 9-year-old boy developed bilateral watering eyes while playing games at school in the summer term. He went home and gradually his eyes returned to normal over 3 h. However, the problem recurred every week. By May he had persistent bilateral conjunctivitis and a “drippy nose”. His symptoms regressed in July and he remained free of symptoms throughout the rest of the year. On investigation, he had a strongly positive skin test to grass pollen but not other test antigens.
CASE 3
An 11-year-old girl ate one bite of a beef hot dog. Within minutes her lips, face, and tongue became swollen, and generalized hives and swelling of her joints developed. She was treated with subcutaneous epinephrine and intramuscular hydroxyzine at an emergency room. Subsequent analysis of the hot dog revealed that it contained milk proteins (which had been added to improve texture). The child had been previously determined to be allergic to milk.
CASE 4
A 33-year-old multigravid woman (gravida 3; para 1) presented in week 11 of her fourth pregnancy. Her first pregnancy had been uneventful and this child was now 13 years old. Her second and third pregnancies had ended with dead fetuses at 36 and 23 weeks respectively. A rising level of antibody to the D antigen of the rhesus blood group had been noted in each pregnancy, but no treatment had been available. Fetoscopy was performed at 19 weeks’ gestation and blood samples obtained. The fetus was found to be Rh-positive with a low hemoglobin. An intravascular intrauterine blood transfusion was performed the next week and repeated at 3-week intervals through the rest of the pregnancy. A live female infant was delivered by Cesarean section at 34 weeks. Her hemoglobin and serum bilirubin levels were normal at birth but she gradually became jaundiced over the next 72 h. An exchange transfusion was given to reduce the level of previously transferred maternal antibody.
CASE 5
A 41-year-old woman presented with gradual weight loss, lethargy and breathlessness on exertion of 4 months’ duration, with intermittent mild wheezing and a cough. She was a non-smoker who bred budgerigars as a hobby. A chest X-ray showed a diffuse, generalized haziness in both lower zones but pulmonary function tests were normal. A Mantoux test was negative. Her serum was tested for precipitating antibodies to budgerigar antigens and a strongly positive reaction was obtained. The patient gave away her birds, and her symptoms regressed over the course of a few months.
CASE 6
A 47-year-old housewife presented with a 3-week history of an acute rash which started beneath her watch. Two weeks later, a further patch appeared at the umbilicus. She had previously noted that she could not wear cheap earrings without triggering a rash on her earlobes. On examination, the appearance was suggestive of contact dermatitis corresponding to nickel in the watch and on a jeans stud. She was patch-tested to a battery of commonly implicated agents: strongly positive results were induced by nickel sulphate and cobalt chloride only.
CASE 7
A 24-year-old student consulted a rheumatologist because of arthralgias in the fingers and knees and red discoloration over the dorsum of the hands and forearm. She had some fatigue and transient morning stiffness but was still able to keep up her busy scholastic schedule and to work part-time.
Further questioning revealed that hair had recently been coming out in increased amounts after combing. She burned easily in the sun and occasionally felt feverish after sun exposure but denied any other rashes, nodules, dysuria, or any other clues to systemic disease. Diagnostic tests revealed a low C3 level of complement and a positive antinuclear antibody (ANA) test.
A 34-year-old female assembly line worker in a machinery factory had noted gradually increasing pain and swelling in several interphalangeal joints over 10 months. She had stiffness in these joints and elsewhere that seemed worse for the first 2 hours in the morning. She denied fevers, rash, or any clues to generalized disease. She had tried aspirin, over the counter ibuprofen, and a prescription for naproxen from her family physician without any help. Laboratory tests showed a normal complete blood cell count, rheumatoid factor positive in a titer of 1:640, and a negative antinuclear antibody assay. An x-ray of the hand showed metacarpophalangeal marginal erosions on the radial side along with some subluxation (joint space narrowing).
A 67-year-old widow presented with gradually increasing tiredness, exertional dyspnea and ankle swelling. Two years earlier she had been found to be anemic and had been treated with oral iron without symptomatic improvement. Laboratory investigations showed a very low hemoglobin. Serum vitamin B12 was 40 ng/l (normal is 170 - 900) but serum folate and iron were normal. Her serum contained strongly positive gastric parietal cell antibodies of IgG class and type I blocking antibodies to intrinsic factor.
The patient was born after an uneventful pregnancy. At 3 months, he developed otitis media and an upper respiratory tract infection. At the ages of 5 and 11 months, he was admitted to hospital with Haemophilus pneumonia. Examination at the age of 18 months showed a pale, thin child whose height and weight were below normal. Immunological investigations showed absent antibody production. The absence of mature B cells in his peripheral blood strongly supported the diagnosis.
A 17-year-old girl who came to the hospital with fever and bruising was eventually found to suffer from acute myelogenous leukemia. Remission of the leukemia was achieved with chemotherapy and allogeneic bone marrow transplantation was attempted, in hope of curing her leukemia. Five days after transplantation, she had no detectable circulating white blood cells and two days thereafter she became febrile. Blood cultures at this time were positive for E. coli. She responded well to antibiotics.
Eight days later she again became febrile, and blood cultures were positive for Candida albicans. Although she was placed on antifungals, she remained febrile for 4 days but rapidly improved upon removal of a venous catheter. At this time (19 days posttransplantation), white blood cells started to appear in her circulation, indicating that the transplanted marrow had successfully engrafted and was starting to function.