Search of intravascular hemolysis in patients with the cutaneous form of loxoscelism

Morena, P.; Nonoyama, Kimiyo; Cardoso, João Luiz Costa; Barreto, Orlando C. de O.

doi:10.1590/s0036-46651994000200009

Cited by 6 publications

(5 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Interestingly, the cutaneous form, a very localized lesion, does not exhibit intravascular hemolysis (15), indicating that the venom does not reach the intravascular compartment in this clinical form. Therefore, we suggest that the two mechanisms may be triggered sequentially, with an initial direct proteolytic action on band 3 followed by further complement activation.…”

Section: Discussionmentioning

confidence: 96%

The calcium-dependent protease of Loxosceles gaucho venom acts preferentially upon red cell band 3 transmembrane protein

Barretto¹,

Satake

Nonoyama

et al. 2003

Braz J Med Biol Res

View full text Add to dashboard Cite

Eighty micrograms red blood cell (RBC) ghosts from patients who had previously exhibited the cutaneous form of loxoscelism (presenting localized dermonecrosis) and the viscerocutaneous form of loxoscelism (presenting dermonecrosis, hemoglobinuria, hematuria, and jaundice) and from controls were incubated with 2.5 µg crude Loxosceles gaucho venom in 5 mM phosphate buffer, pH 7.4, at 37ºC. Among all membrane proteins, quantitative proteolysis of the important integral transmembrane protein 3 increased with venom dose and with incubation time from 30 to 120 min, as demonstrated by gel densitometry. Similar quantitative data were obtained for RBC ghosts from patients and from control subjects, a fact that argues against the possibility of genetic factors favoring the hemolytic viscerocutaneous form. These data suggest that the clinical forms may be different types of the same disease, with the viscerocutaneous form being the result of large amounts of intravascularly injected venom and the superficial form being the result of in situ venom action. Since protein 3 is a housekeeping integral membrane protein, whose genetic deficiency leads to hemolytic anemia, it is reasonable to relate it to the hemolysis which occurs in the viscerocutaneous form of loxoscelism. The venom protease responsible for the process was not inhibited after 120-min incubation by 0.2 mM paramethylsulfonyl fluoride or by 0.2 mM Nethylmaleimide but was inhibited by 25 mM ethylenediaminetetraacetic acid (a calcium-chelating agent) in 5 mM phosphate buffer at pH 7.4, which suggests that the enzyme is a calcium-dependent metalloprotease.

show abstract

Section: Discussionmentioning

confidence: 96%

The calcium-dependent protease of Loxosceles gaucho venom acts preferentially upon red cell band 3 transmembrane protein

Barretto¹,

Satake

Nonoyama

et al. 2003

Braz J Med Biol Res

View full text Add to dashboard Cite

show abstract

“…The presence of multiple necrotic lesions indicates an etiology other than Loxosceles envenomation, such as pyoderma gangrenosum (i.e., a rare skin disease with recurrent deep skin ulcers and impaired cell -mediated immunity). 132 The appearance of diffuse macular erythema over the trunk is a good prognostic sign. Typically, severe lesions become obvious within 12 -24 hours, and the lack of necrotic signs within 48 -96 hours indicates that necrosis will not occur.…”

Section: Cutaneous Loxoscelismmentioning

confidence: 99%

“…152 Analysis of the urine during hemolysis may or may not demonstrate free haptoglobin with a positive urine dipstick for blood and minimal evidence of erythrocytes on microscopic examination because hemolysis may occur in extravascular areas (e.g., spleen). Reduced hemoglobin concentrations and increased plasma -free haptoglobin concentrations develop during intravascular hemolysis, and normal serum haptoglobin concentrations exclude the presence of intravascular hemolysis.…”

Section: Abnormalitiesmentioning

confidence: 99%

Spiders (Order: Araneae)

Barceloux

2008

Medical Toxicology of Natural Substances

View full text Add to dashboard Cite

“…A normal haptoglobin level is less than 1 dL and will rule out intravascular hemolysis. 78 The serum will appear pinkish at levels greater than 50 dL. 14 Creatine kinase level should be monitored when patients present with extensive cutaneous involvement and should be rechecked after 12 hours if abnormal or if the patient appears clinically ill.…”

Section: Laboratory Diagnosismentioning

confidence: 99%