Heme, like chlorophyll, is a primordial molecule and is one of the fundamental pigments of life. Disorders of normal heme synthesis may cause human diseases, including certain anemias (X-linked sideroblastic anemias) and porphyrias. Porphyrias are classified as hepatic and erythropoietic porphyrias based on the organ system in which heme precursors (5-aminolevulinic acid (ALA), porphobilinogen and porphyrins) are chiefly overproduced. The hepatic porphyrias are further subdivided into acute porphyrias and chronic hepatic porphyrias. The acute porphyrias include acute intermittent, hereditary copro-, variegate and ALA dehydratase deficiency porphyria. Chronic hepatic porphyrias include porphyria cutanea tarda and hepatoerythropoietic porphyria. The erythropoietic porphyrias include congenital erythropoietic porphyria (Gűnther’s disease) and erythropoietic protoporphyria. In this review, we summarize the key features of normal heme synthesis and its differing regulation in liver versus bone marrow. In both organs, principal regulation is exerted at the level of the first and rate-controlling enzyme, but by different molecules (heme in the liver and iron in the bone marrow). We also describe salient clinical, laboratory and genetic features of the eight types of porphyria.

Once suspected, the diagnosis of porphyria can be rapidly established by checking random urinary porphobilinogen. Initial management of acute porphyria includes discontinuation of all potentially harmful drugs and management of symptoms. Acute attacks should be treated emergently with intravenous heme and glucose to avoid considerable morbidity and mortality. Acute attacks last a few days, and the majority of patients are asymptomatic between attacks. Prognosis is good if the condition is recognized early and treated aggressively.

Background Nonsteroidal anti-inflammatory drugs (NSAIDs) are one of the most commonly used classes of medications and have been associated with hepatotoxicity. Studies of liver injury from NSAIDs have been retrospective and prospective data are lacking that provide details of cases. Aim To report the presenting feature and outcomes of subjects with severe drug induced liver injury from NSAIDS. Methods The U.S. Drug Induced Liver Injury Network is a prospective registry of severe idiosyncratic drug hepatotoxicity. All patients are evaluated in a standard fashion and followed for at least 6 months after onset. Results Of 1,221 DILIN cases that were adjudicated, 30 cases were attributed to 8 different NSAIDs. The mean age was 52 years old, 24 (80%) were women, and 21 (70%) were Caucasian. The mean latency to onset of laboratory abnormalities was 67 days. Common signs and symptoms at presentation were nausea (73%), jaundice (67%), and dark urine (67%). Mean peak serum AST, ALT, total bilirubin, and alkaline phosphatase were 898 U/L, 1060 U/L, 12.2 mg/dL, and 326 U/L, respectively. The most common pattern of injury was hepatocellular (70%) and autoantibodies were detected in 33% of cases. Diclofenac, was the most frequently implicated NSAID (16/30 cases), and characterized by hepatocellular injury in all cases. Seventeen cases resulted in hospitalization or prolongation of hospitalization and one patient died from complications of Stevens-Johnson syndrome rather than liver failure due to diclofenac. Conclusions Hepatocellular injury is the most common pattern seen with NSAID hepatotoxicity and diclofenac is the most frequently implicated agent. Given the number of available NSAID alternatives, diclofenac use should be limited to patients who fail other NSAIDs and a high level of suspicion for hepatotoxicity should be maintained.

First reported in 1978, occult hepatitis B is a term used to describe the presence of hepatitis B virus (HBV) DNA without hepatitis B surface antigenemia. The prevalence of occult HBV is unclear and depends in part on the sensitivity of the hepatitis B surface antigen (HBsAg) and DNA assays used as well as the prevalence of HBV infection in the study population. The origin of occult HBV also remains in question. Several mechanisms have been hypothesized including mutations in the regulatory regions of the HBV genome, persistence of Ig-bound HBV immune complexes, viral interference, and blockage of free HBsAg secretion. Occult HBV has important clinical implications such as transmission through blood transfusion, reactivation in the setting of immunosuppression, and interference with hepatitis C treatment. To date, there is little date pertaining to the treatment of occult HBV outside of the setting of chemotherapy-induced HBV reactivation.