Paroxysmal Nocturnal Hemoglobinuria (PNH)

WHAT IS IT?

Paroxysmal nocturnal hemoglobinuria (PNH) is a disorder characterized by complement mediated hemolysis. 

WHAT CAUSES IT?

PHN is most often caused by a mutated phsphatidylinositol glycan class A (PIGA) gene: This gene helps synthesize the glycosylphatidylinositol (GPI) anchor protein which helps attach several surface cell proteins (such as CD55/DAF/Decay acceleration factor, CD59 MAC inhibitory protein) that inactivate complement and prevent the RBC from being destroyed. The absence of these proteins result in uncontrolled complement mediated hemolysis. 

WHY IS IT CONCERNING MEDICALLY?

PNH will lead to the following medical complications:

  • Fatigue: as a result of the anemia (secondary to hemolysis)
  • Jaundice: resulting from the uncontrolled hemolysis 
  • Thrombosis: in PNH there is an increased risk of thrombosis at atypical sites (such as hepatic, portal, or cerebral veins).
  • Pancytopenia: this can occur as a result of stem cell injury. 
  • Hemosiderosis: the chronic hemolysis of iron containing red blood cells can lead to iron deposition in the kidney, which can interfere with renal function, and causes interstitial scarring/cortical infarcts. 
  • Chronic kidney disease: the aforementioned risks of hemosinderossi combined with microvascular thrombosis greatly increase the risk of chronic kidney disease.  
  • Acute myeloid leukemiathis develops in a large fraction of patients with this condition. 
WHAT IS THE INTIAL PRESENTATION?

Patient Chief Complaints:

 

Detected Medical Problems:

 

WHAT ARE IMPORTANT ELEMENTS OF THE MEDICAL HISTORY?

Risk Factors:

 

Medical History:

 

WHAT ARE IMPORTANT FEATURES OF THE PHYSICAL EXAM?

Vital Signs:

 

Other:

 

CLINICAL WORKUP: SERUM STUDIES

 

CLINICAL WORKUP: IMAGING

 

CLINICAL WORKUP: OTHER

 

HOW DO WE NARROW THE DIFFERENTIAL?

Conditions that present similarly and how to exclude them:

 

WHAT IS OUR THRESHOLD FOR DIAGNOSING THIS CONDITION?

 

PATIENT MANAGMENT: SYMPTOM RELEIF

 

PATIENT MANAGEMENT: DISEASE TREATMENT

 

PATIENT MANAGEMENT: PROPHYLACTIC MEASURES

 

COULD THIS HAVE BEEN PREVENTED?

 

ARCHIVE OF STANDARDIZED EXAM QUESTIONS 

This archive compiles standardized exam questions that relate to this topic.

 

Page Updated: 04.09.2017