Mechanical hemolytic anemia is a form of
hemolytic anemia
Hemolytic anemia or haemolytic anaemia is a form of anemia due to hemolysis, the abnormal breakdown of red blood cells (RBCs), either in the blood vessels (intravascular hemolysis) or elsewhere in the human body (extravascular). This most commonly ...
due to mechanically induced damage to
red blood cell
Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek ''erythros'' for "red" and ''kytos'' for "hol ...
s. Red blood cells, while flexible, may in some circumstances succumb to physical shear and compression.
[Dan L. Longo, ''Harrison's Hematology and Oncology'', 2010, ; page 121.] This may result in
hemoglobinuria
Hemoglobinuria is a condition in which the oxygen transport protein hemoglobin is found in abnormally high concentrations in the urine. The condition is caused by excessive intravascular hemolysis, in which large numbers of red blood cells (RBCs) ...
. The damage is induced through repetitive mechanical motions such as prolonged
marching
Marching refers to the organized, uniformed, steady walking forward in either rhythmic or route-step time; and, typically, it refers to overland movements on foot of military troops and units under field orders. Marching is often performed t ...
(''march hemoglobinuria'') and marathon running.
[Reinhold Munker, Erhard Hiller, Jonathan Glass, Ronald Paquette, ''Modern Hematology: Biology and Clinical Management'', 2007, page 126, .] Mechanical damage can also be induced through the chronic condition
microangiopathic hemolytic anemia
Microangiopathic hemolytic anemia (MAHA) is a microangiopathic subgroup of hemolytic anemia (loss of red blood cells through destruction) caused by factors in the small blood vessels. It is identified by the finding of anemia and schistocytes ...
or due to
prosthetic heart valves.
Cause
Repetitive impacts to the body may cause mechanical trauma and bursting (
hemolysis
Hemolysis or haemolysis (), also known by several other names, is the rupturing ( lysis) of red blood cells (erythrocytes) and the release of their contents ( cytoplasm) into surrounding fluid (e.g. blood plasma). Hemolysis may occur in viv ...
) of red blood cells. This has been documented to have occurred in the feet during running
and hands from Conga or
Candombe
''Candombe'' is a style of music and dance that originated in Uruguay among the descendants of liberated African slaves. In 2009, the United Nations Educational, Scientific and Cultural Organization (UNESCO) inscribed ''candombe'' in its Repres ...
drumming.
Defects in red blood cell membrane proteins have been identified in some of these patients.
Free haemoglobin is released from lysed red blood cells and filtered into the urine.
Hemolytic phenomena
March haemoglobinuria
March
hemoglobinuria
Hemoglobinuria is a condition in which the oxygen transport protein hemoglobin is found in abnormally high concentrations in the urine. The condition is caused by excessive intravascular hemolysis, in which large numbers of red blood cells (RBCs) ...
, occurs when
hemoglobin
Hemoglobin (haemoglobin BrE) (from the Greek word αἷμα, ''haîma'' 'blood' + Latin ''globus'' 'ball, sphere' + ''-in'') (), abbreviated Hb or Hgb, is the iron-containing oxygen-transport metalloprotein present in red blood cells (erythroc ...
is seen in the urine after repetitive impacts on the body, particularly affecting the feet. The word "march" is in reference to the condition arising in soldiers who have been marching for long periods; the condition was first documented in 1881.
Runner’s macrocytosis
Runner's macrocytosis is a phenomenon of increased red blood cell size as a compensatory mechanism for increased red blood cell turnover. The impact forces from running can lead to red blood cell hemolysis and accelerate red blood cell production. This can shift the ratio of red blood cells towards younger, larger cells. This shift may be reflected in higher than normal
mean corpuscular volume
The mean corpuscular volume, or mean cell volume (MCV), is a measure of the average volume of a red blood corpuscle (or red blood cell). The measure is obtained by multiplying a volume of blood by the proportion of blood that is cellular (the hem ...
(MCV) values, an indicator of red blood cell size.
This is not a pathological condition but may indicate a propensity toward iron deficiency anemia due to high red blood cell turnover.
References
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Acquired hemolytic anemia