Blood Vessels Under Attack: Sudden Critical Illness in Days—This Disease Has a High Mortality Rate

"She could still walk with a mobility aid a few days ago—how did she suddenly become critically ill?" In early September this year, 74-year-old Ms Bao suffered an abrupt health crisis. Within just a few days, her condition deteriorated rapidly from general fatigue to acute kidney failure. The culprit was atypical hemolytic uremic syndrome (aHUS). Fortunately, thanks to precise treatment by a multidisciplinary team at Sir Robert Run Shaw Hospital, Zhejiang University School of Medicine, she was successfully weaned off dialysis on the 22nd day of onset and regained a healthy life.

Hidden Lethal Risks in Everyday Discomfort

At first, Ms Bao only felt extremely tired and had a poor appetite. Mistaking it for heat-related discomfort, she took Huoxiang Zhengqi Pills on her own and paid no further attention. However, over the next few days, her urine output decreased significantly, her abdomen gradually swelled, and her legs became visibly swollen—even walking with a mobility aid became impossible.

Her family rushed her to a local community hospital, where the test results were alarming: her hemoglobin level was only 59 g/L, far below the normal range of 115–150 g/L for adult women; her creatinine level soared to 1,197 μmol/L, vastly exceeding the normal standard of 41–81 μmol/L. These two key indicators confirmed that Ms Bao was suffering from severe anemia and acute kidney failure, a life-threatening condition. She was then urgently transferred to the Emergency Department of the Qingchun Campus of Sir Robert Run Shaw Hospital.

Multiple Abnormalities Pinpoint the Culprit

"Her health check-up was completely normal just three months ago—how could her condition worsen so suddenly?" During the consultation, Dr. Wenyu Xiang from the Nephrology Department noted that Ms Bao’s illness was more complex than "anemia complicated by kidney failure." She also presented elevated lactate dehydrogenase, a sharp rise in D-dimer, metabolic acidosis, electrolyte imbalance, and other abnormalities. Due to her critical condition, Ms Bao was immediately admitted to the intensive care unit (ICU) for emergency treatment, including blood transfusions, hemodialysis, and high-dose hormone therapy.

Further examinations revealed new abnormalities identified by Chief Physician Libin Ma from the Nephrology Department: Ms Bao’s hemoglobin level failed to rise after blood transfusions, and abnormally shaped red blood cells of varying sizes were found in her blood. While her platelet count remained within the normal range, it had dropped significantly from previous levels. A bone marrow aspiration test showed active red blood cell production, along with decreased complement C3 and normal C4 levels. These clues pointed to a dangerous condition—thrombotic microangiopathy (TMA), a disease that causes numerous unexplained blood clots in small blood vessels, blocking blood flow, damaging tissues, and triggering life-threatening symptoms.

To identify the trigger for the blood clots, Ms Bao was transferred to the Dayunhe Campus once her condition stabilized, where her care was taken over by the team led by Deputy Chief Physician Junnan Wu from the Nephrology Department. Dr. Yimeng Zhu promptly arranged a renal biopsy and complement system tests. The results showed: serum total complement CH50 was 54.8 U/mL (normal: 23–46 U/mL), soluble complement membrane attack complex sC5b-9 reached 1,734 ng/mL (normal: 75–219 ng/mL), with low C3 and C1q levels and normal C4 levels—strongly indicating the involvement of the complement system in the disease.

Combined with other test results, the team ruled out thrombotic thrombocytopenic purpura (TTP), typical hemolytic uremic syndrome (HUS), and other conditions, ultimately identifying the culprit as atypical hemolytic uremic syndrome (aHUS), a rare and life-threatening disease.

Understanding aHUS: The Uncontrolled "Defense Force" Attacks the Body

Why is aHUS so dangerous? Think of the human complement system as a "defense force" that protects health. Normally, it precisely fights off pathogens. But in patients with aHUS, this force spirals out of control, mistaking the body’s own blood vessels for "enemies" and launching indiscriminate attacks:

• Red blood cells are destroyed (hemolytic anemia), causing severe fatigue and pale skin.

• Platelets are massively depleted (thrombocytopenia), increasing the risk of skin bruising and gum bleeding.

• Blood clots form in tiny blood vessels, blocking circulation and damaging organs—especially the kidneys (triggering acute kidney failure, marked by soaring creatinine levels and reduced urine output). The condition can also affect the brain, heart, intestines, and other organs, leading to fatal complications.

Due to its sudden onset and rapid progression, aHUS has a high mortality rate. Without timely treatment, many patients require long-term dialysis or face life-threatening outcomes.

"Specialized Treatment" + Multidisciplinary Collaboration: The Elderly Patient Regains Hope

After confirming the aHUS diagnosis, immediate treatment was critical. Conventional therapies such as hormone treatment and plasma exchange have limited efficacy for aHUS, and Ms Bao’s kidney function and hemoglobin levels showed no improvement. A precise treatment plan and multidisciplinary support were urgently needed—diagnosing and treating aHUS inherently relies on cross-specialty collaboration. From emergency rescue and repeated nephrology consultations to ICU life support and precise laboratory testing, teams from the hospital’s Nephrology, Hematology, Critical Care Medicine, and Laboratory Medicine departments worked closely together, laying a solid foundation for subsequent treatment.

Modern medicine has a specialized treatment for aHUS: complement inhibitors (e.g., eculizumab). These biologics act like a "stop button" for the overactive complement system, halting further attacks on blood vessels and organs. After thorough communication with the family and implementing strict monitoring and infection prevention measures, Dr. Junnan Wu’s team, drawing on multidisciplinary clinical data, initiated complement inhibitor therapy for Ms Bao.

Remarkable improvements were seen after three infusions: her hemoglobin rose from a low of 48 g/L to 85 g/L, eliminating her reliance on blood transfusions; her creatinine dropped from 1,197 μmol/L to 142 μmol/L; her urine output returned to normal from near anuria; and her complement C3, sC5b-9, and other indicators normalized. On the 22nd day of onset, Ms Bao’s dialysis catheter was removed, and she was completely weaned off dialysis. After nearly a month of treatment, her condition stabilized, kidney function continued to recover, and she was discharged—only requiring regular follow-ups and maintenance therapy thereafter.

"Rare diseases do not require isolated treatment." This success story exemplifies how multidisciplinary collaboration and precision medicine offer hope amid life-threatening crises.

Urgent Medical Reminder: Seek Prompt Care for These Symptoms

While aHUS is life-threatening, early detection, diagnosis, and treatment drastically improve cure rates. Research shows that 83% of aHUS patients can be weaned off dialysis with timely complement inhibitor therapy!

Seek immediate medical attention if you experience the following sudden or worsening symptoms:

• Severe fatigue and pale skin (possible hemolytic anemia).

• Skin petechiae, bruising, gum bleeding, or nosebleeds (possible thrombocytopenia).

• Significantly reduced urine output and body swelling (possible kidney damage).

Special Reminder

Extra vigilance is needed if these symptoms occur alongside severe hypertension, pregnancy (especially postpartum), autoimmune diseases (e.g., lupus), malignant tumors, organ transplantation, or certain medications.