Clinical Disease States Related to Mutations of the NOD2 Gene: A Case Report and Literature Review

Nucleotide-binding oligomerization domain-containing protein 2 (NOD2) is a protein encoded by the NOD2 gene and plays an important role in the immune system. NOD2 is an intracellular pattern recognition receptor (PRR) responsible for the recognition of pathogens as well as the activation of many biochemical processes within cells of the host immune system. Mutations of the NOD2 gene can significantly impact the host's immune response against a variety of pathogens. In addition to immunodeficiency, mutations of the NOD2 gene have also been linked with several atopic diseases and autoimmune conditions such as rheumatoid arthritis and Crohn's disease (CD). There is also a distinct set of autoinflammatory conditions that are now classified as NOD2-associated autoinflammatory diseases (NAID). We present a case of a 63-year-old female with common variable immunodeficiency, eosinophilic asthma, and rheumatoid arthritis who was found to have a NOD2 mutation on genetic testing. As genetic testing continues to gain popularity, several disease states that were previously thought to be unrelated are now being recognized as originating from a common genetic defect.

A Case of Angioimmunoblastic T-cell Lymphoma That Mimics As Autoimmune Diseases and Infections

Angioimmunoblastic T-cell lymphoma (AITL) is an aggressive malignancy with a presentation like either autoimmune diseases, drug reactions, or infections. We hereby present a unique case of AITL. A 61-year-old Caucasian male with a past medical history of chronic obstructive pulmonary disease (COPD) presented to the emergency department with a rash over his bilateral knees, shortness of breath, and productive cough of few days. He was managed for suspected COPD exacerbation associated with community-acquired pneumonia. On the day of admission patient was having an itchy maculopapular rash, ecchymosis on the left flank, and generalized lymphadenopathy. Physical exam showed generalized lymphadenopathy. Laboratory tests revealed leukocytosis, thrombocytopenia and were positive for multiple autoantibodies. Epstein-Barr virus polymerase chain reaction and hepatitis B virus core antibody were positive. Skin biopsy revealed findings suggestive of a small vessel vasculitis. Inguinal lymph node biopsy showed AITL. The patient recovered with chemotherapy. The case illustrates that clinical presentation of AITL mimics rheumatologic disorders and infections. This complexity could arise from the follicular T helper cell, which is an important checkpoint for B cell activation and differentiation. Additionally, skin involvement is one of the important findings of AITL and a variety of lesions have been reported as skin manifestations.

Autoimmune-like Drug-induced Liver Injury Caused by Atorvastatin and Demonstration of the Safety Profile of Pravastatin: A Case Report and Literature Review

Statin-induced liver injury is a well-recognized but rare phenomenon with hepatocellular, cholestatic, and mixed phenotypes. Most studies do not recommend regular monitoring of liver function tests (LFTs) after starting statins unless clinically indicated. We report a case of autoimmune-like atorvastatin-induced liver injury (aminotransferases > 5 times the upper limit of normal) that was detected on routine follow-up after three months in an asymptomatic patient. In addition to elevation in transaminases, the patient had weakly positive ANAs. Anti-smooth muscle antibody (ASMA) was positive in titers of 1:680. Screening for viral hepatitis A-E was negative. Other diagnostic investigations showed complete blood examination, including eosinophils, renal function tests, electrolytes, total protein, albumin, prothrombin time, activated partial thromboplastin time (aPTT), international normalized ratio (INR), serum ferritin, and iron saturation to be in the normal range. Ultrasound and computed tomography (CT) abdomen showed normal liver, gall bladder, biliary tree, and pancreas. The patient was managed as a case of autoimmune-like drug-induced liver injury (DILI) caused by atorvastatin and the medication was discontinued. LFTs returned to completely normal 30 days after the discontinuation of atorvastatin. Furthermore, switching to pravastatin for dyslipidemia management four months after stopping atorvastatin did not lead to hepatotoxicity, illustrating the safety profile of pravastatin in patients who are unable to tolerate atorvastatin.