What does HSOS mean in SYNDROMES

Meaning of HSOS

Hepatic sinusoidal obstruction syndrome (HSOS) is a rare disorder of the liver that is often seen in bone marrow transplant recipients who have received immunosuppressive therapy as part of their treatment plan. It results in the blockage of liver veins due to an abnormal reaction to certain drugs, radiation or chemotherapy treatments, causing symptoms such as abdominal pain, jaundice, increased bilirubin levels, hepatomegaly (an enlarged liver), ascites (fluid accumulation in the abdomen) and hepatic insufficiency or even cirrhosis if left untreated.

Causes & Risk Factors

The exact cause of HSOS is unclear, but it has been suggested that certain drugs used in bone marrow transplants may trigger an immune reaction which results in the blockage of the veins which lead out from the liver's central area known as the sinusoids. Other risk factors include age over 40 years old; high doses of glucocorticoid therapy; use of some chemotherapeutic agents; pre-existing prior viral infections including hepatitis C virus or Epstein-Barr virus; receiving multiple courses of chemotherapy; prior history with hematologic malignancy or other solid tumors; female gender; foreign body granulomas caused by implants like pacemakers or stents used for cardiac procedures; HIV infection; renal insufficiency; hyperlipidemia (high cholesterol); exposure to herbal supplements and alcohol consumption.

Diagnosis

Diagnosing HSOS can be difficult due to its rarity and lack of awareness about this disorder among clinicians. In most cases patients will undergo physical examination with associated laboratory tests such as complete blood count (CBC), serum biochemistry tests including bilirubin levels, prothrombin time/INR and alanine aminotransferase (ALT). Imaging studies such as ultrasound or computed tomography scan are often used to assess for hepatomegaly (enlargement) or associated ascites. Biopsy may also be used to confirm diagnosis if it’s clinically indicated.

Treatment

Treatment for HSOS involves decreasing exposure to causative agents if possible while managing complications with supportive care such as fluids for dehydration and electrolyte imbalances, nutritional support including enteral tube feeding if needed along with medications like diuretics for fluid retention (ascites), anticoagulants for thrombosis/venous occlusion plus supplementation with vitamins A & E and antioxidants like N-acetylcysteine for hepatocellular protection needs consideration depending on patient’s clinical condition.