Faculty Bibliography

PURPOSE OF REVIEW/OBJECTIVE:Calcium pyrophosphate deposition disease (CPPD) arises from calcium pyrophosphate deposition throughout the body, leading to different clinical syndromes that may be diagnosed using various imaging modalities. The purpose of this review is to highlight recent updates in the imaging of CPPD. RECENT FINDINGS/RESULTS:Conventional radiography remains the initial test when imaging CPPD; but musculoskeletal ultrasound and conventional computed tomography (CT) may also assist in diagnosing and characterizing CPP deposits, with increased sensitivity. Dual-energy CT is also being used to differentiate CPP crystals from other crystal deposition diseases. CPP discitis has been diagnosed with MRI, but MRI has lower sensitivity and specificity than the aforementioned imaging studies in CPPD diagnosis. Assorted imaging modalities are increasingly used to diagnose CPPD involving atypical joints, avoiding invasive procedures. Each modality has its advantages and disadvantages. Future imaging may be able to provide more utility than what is currently available.

LEARNING OBJECTIVE #1: Recognize the presentation of pure red cell aplasia caused from Azathioprine LEARNING OBJECTIVE #2: Distinguish key parts of history and lab findings that help diagnose pure red cell aplasia CASE: A 42-year-old female with a medical history of Crohn's disease, mixed connective tissue disease (MCTD), hypertension, and stage 3 chronic kidney disease, presented to the hospital with a complaint of fatigue and weakness for the previous two weeks. She was taking azathioprine, vedolizumab, and prednisone 5 mg for her Crohn's disease and MCTD. In addition, allopurinol was added 1.5 months prior. Initial lab workup revealed a macrocytic anemia with a hemoglobin of 7.5 mg/dl and a mean corpuscular volume of 100.9 fl. Previous CBCs showed a hemoglobin around 14 mg/dl with normal mean corpuscular volume. She reported no history concerning for bleed. She had normal ESR and CRP levels and an unremarkable CT abdomen. Folate and B12 levels were normal. She had a haptoglobin of 152 mg/dl, an LDH of 218 units/liter, and total bilirubin of .3 mg/dL, inconsistent with hemolysis. A peripheral smear did not reveal hypersegmented neutrophils. Her reticulocyte count was 0.58%, and absolute count of 0.013, which suggested bone marrow suppression. Her white blood cell count and platelets were both normal. A 6- thioguanine nucleotides RBC level was elevated at 559 pmol/8x10(8)RBC (normal 235-400). Her azathioprine was subsequently discontinued, and her symptoms improved. A CBC on follow up visit approximately 3.5 months after discharge showed a hemoglobin of 13 mg/dl. IMPACT/DISCUSSION: Azathioprine is a purine analogue that interferes with DNA synthesis and inhibits proliferation of rapidly growing cells. 6-mercaptopurine (6-MP) is a drug metabolite of azathioprine that is used in the treatment of autoimmune diseases such as Crohn's disease. This occurs in part by the active metabolite, 6-Thioguanine nucleotide (6- TGN). Bone marrow suppression has been documented as a possible adverse effect of azathioprine, which is thought to occur via 6-TGN. Rarely, the suppression can be specific for erythrocyte generation and lead to a pure red cell aplasia (PRCA). Of note, our patient recently began allopurinol treatment to attempt to increase efficacy of the azathioprine. This occurs in part due to the inhibition of one of the metabolic pathways of 6-MP via Xanthine oxidase which will lead to increased therapeutically active 6-TGN. This simultaneous use likely contributed to the elevated 6-TGN metabolites and myelosuppression. This occurs more commonly in patients with low levels of Thiopurine methyl transferase (TPMT), however, aplastic anemia secondary to azathioprine can occur in patients with normal TPMT activity.
CONCLUSION(S): Allopurinol is often added in combination with azathioprine in the treatment for Crohn's disease. If these patients present with fatigue and macrocytic anemia, drug induced pure red cell anemia must be considered

Patients with systemic lupus erythematosus (SLE) are at increased risk for infection including opportunistic infections. Fungal infection in particular can be difficult to diagnose and treat and often can be life-threatening in the immunocompromised patient. We present a case in which a patient with SLE presented to the hospital with shortness of breath and cough. Throughout the hospital course, the patient's condition continued to decline leading to acute respiratory failure, and eventually, the patient expired. Postmortem autopsy revealed invasive fungal aspergillosis infection involving the heart, lungs, and brain. Earlier diagnosis and treatment with empiric antifungals may improve survival in these patients.

PURPOSE OF REVIEW/OBJECTIVE:Jaundice, the physical finding associated with hyperbilirubinemia, results when the liver is unable to properly metabolize or excrete bilirubin. The purpose of this review is to examine some of the most common causes of jaundice in adults, provide insight into the diagnostic evaluation of jaundice, and review information on the outcomes of patients with jaundice. RECENT FINDINGS/RESULTS:An elevated level of bilirubin almost always indicates the presence of an underlying disease state. The best approach to evaluating a patient with jaundice is to start with a careful history and physical examination, followed by imaging assessment of the biliary tree and liver. There are algorithm models that incorporate bilirubin levels in their predictor models for outcomes in patients with chronic liver disease (i.e., the model for end-stage liver disease). However, there are few studies that have examined the outcomes of patients with jaundice. SUMMARY/CONCLUSIONS:Evaluation of patients with jaundice starts with a careful history and physical examination, followed by directed imaging of the biliary tree and liver. Although jaundice is generally believed to be a serious medical condition, there is little literature that addresses outcomes in patients with jaundice.