Microangiopathic hemolytic anemia: Difference between revisions

Revision as of 14:52, 21 July 2014

Introduction

Microangiopathic hemolytic anemia (MAHA) = variety of conditions that result in damaged endothelium of small vessels causing platelet aggregation and fibrin deposition which leads to shearing forces within these small vessels causing an intravascular fragmentation hemolysis

Diagnosis

Clinical features + heme labs with red blood cell fragments or schistocytes.^[1]
May have bleeding and thrombosis

Differential Diagnosis

Most common causes: DIC, TTP, HUS
Other medical causes: malignant hypertension, HELLP, Antiphospholipid Syndrome (APS), scleroderma, Paroxysmal Nocturnal Hemoglobinuria (PNH), malignancy, renal allograft rejection, vasculitides like polyarteritis nodosa and Wegener's granulomatosis
Drugs: chemotherapy; Clopidogrel (Plavix) associated with TTP
Nonvascular causes: prosthetic valve (more common w/ mechanical, more common at aortic valve), LVAD, TIPS, coil embolization, patched AV shunt, AVM

Work-Up

Peripheral smear, hemoglobin, platelets, PT/INR, PTT, fibrinogen, FDPs, D-dimer, haptoglobin, LDH, bilirubin
- Schistocytes (aka Helmet cells) secondary to fragmentation hemolysis classic finding on peripheral smear

Lab Findings

Schistocytes
High: +/- LDH and unconjugated bilirubin
Low: Hgb, platelets, +/- haptoglobin

General Rules

DIC= elevated PT/INR/PTT/FDPs/D-dimer, low fibrinogen^[1]

TTP/HUS = normal PT/INR/PTT/FDPs/D-dimer/fibrinogen^[1]

Sources

↑ ^1.0 ^1.1 ^1.2 Scully. Marie et al. Guidelines on the diagnosis and management of thrombotic thrombocytopenic purpura and other thrombotic microangiopathies. Br J Haematol. 2012 Aug;158(3):323-35. PDF

Authors:

[guidelines-1] 1.0 ^1.1 ^1.2 Scully. Marie et al. Guidelines on the diagnosis and management of thrombotic thrombocytopenic purpura and other thrombotic microangiopathies. Br J Haematol. 2012 Aug;158(3):323-35. PDF

[1]

@@ Line 4: / Line 4: @@
 ==Diagnosis==
-*Clinical features + heme labs
+*Clinical features + heme labs with red blood cell fragments or schistocytes.<ref name="guidelines">Scully. Marie et al. Guidelines on the diagnosis and management of
+thrombotic thrombocytopenic purpura and other thrombotic microangiopathies. Br J Haematol. 2012 Aug;158(3):323-35. [http://www.bcshguidelines.com/documents/BJH_TTP_Guideline_0512.pdf PDF]</ref>
 *May have bleeding and thrombosis
+==Differential Diagnosis==
-==DDx==
 *Most common causes: [[DIC]], [[TTP]], [[HUS]]
 *Other medical causes: [[malignant hypertension]], [[HELLP]], [[Antiphospholipid Syndrome (APS)]], [[scleroderma]], [[Paroxysmal Nocturnal Hemoglobinuria (PNH)]], malignancy, renal allograft rejection, vasculitides like [[polyarteritis nodosa]] and [[Wegener's granulomatosis]]
-*Drugs: chemotherapy; [[Plavix]] (clopidogrel) associated with [[TTP]]
+*Drugs: chemotherapy; [[Clopidogrel]] (Plavix) associated with [[TTP]]
 *Nonvascular causes: prosthetic valve (more common w/ mechanical, more common at aortic valve), [[LVAD]], [[TIPS]], coil embolization, patched AV shunt, [[AVM]]
 ==Work-Up==
@@ Line 19: / Line 18: @@
 **Schistocytes (aka Helmet cells) secondary to fragmentation hemolysis classic finding on peripheral smear
+===Lab Findings===
+*Schistocytes
+*High: +/- LDH and unconjugated bilirubin
+*Low: Hgb, platelets, +/- haptoglobin
-*All MAHAs =
+===General Rules===
-**Schistocytes
+*[[DIC]]= '''elevated''' PT/INR/PTT/FDPs/D-dimer, '''low''' fibrinogen<ref name="guidelines"></ref>
-**High: +/- LDH and bili
-**Low: Hgb, platelets, +/- haptoglobin
-*DIC = '''elevated''' PT/INR/PTT/FDPs/D-dimer, '''low''' fibrinogen
-*TTP/HUS = '''normal''' PT/INR/PTT/FDPs/D-dimer/fibrinogen
+*[[TTP]]/[[HUS]] = '''normal''' PT/INR/PTT/FDPs/D-dimer/fibrinogen<ref name="guidelines"></ref>
@@ Line 38: / Line 36: @@
 *[[HIT]]
+==Sources==
+<references/>
 [[Category:Heme/Onc]]