We examined the immunohistochemical distributions of
ubiquitin (Ub) and
myoglobin (Mb) in human kidney tissues to assist the pathological assessment of death due to
trauma. Medicolegal autopsy cases at our institute (n=138: 0-96 years of age, 105 males and 33 females) were examined. Causes of death were
blunt injury (n=31), sharp injury (n=15),
poisoning (n=11),
drowning (n=10), fire fatalities (n=25),
hypothermia (n=7), asphyxiation (n=14),
hyperthermia (n=3), and natural diseases (n=22) for controls. Immunostaining of Ub and Mb was performed on the
formalin-fixed
paraffin-embedded kidney tissue sections. Quantitative analyses by estimating the proportion of Ub- and Mb-positive cells (%positivity) of renal tubule epithelial cells showed that the positivities for Ub and Mb were higher in subjects who died due to fire,
blunt injury, sharp injury and fatal
hypothermia than in other groups. The Ub-positivity correlated with the severity of airway thermal injury in fire deaths, survival time in
blunt injury, and
serum markers for
renal failure in deaths due to sharp injury. Concomitant increases in the tubular Mb- and Ub-positivities were characteristic to deaths from injury and
hypothermia. These findings suggest that Ub may serve as a sensitive
indicator of the fatal influence of
traumas.