A Retrospective Analysis of Tissue-Fixed Immunoreactants from Skin Biopsies Maintained in Michel’s Medium

Jones, Stephanie; Ramírez-Salas, Jesús Eduardo; McGrath, John A.; Palmer, Ian R.; Bhogal, B.S.; Black, M.M.

doi:10.1159/000246955

Cited by 31 publications

(9 citation statements)

References 1 publication

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“…The second observation was the split that occurred at the DEJ in many specimens that were preserved in MM for 2 weeks or more. A similar observation has been reported in a prior study . In contrast, none of the samples in honey (in both group I and II) showed a BMZ split.…”

Section: Discussionsupporting

confidence: 90%

“…This medium probably preserves immuno‐antigenicity through its ability to precipitate macromolecules while inhibiting proteolytic enzymes. Immunoreactants may be demonstrable by DIF even at 6 months, indicating the reliability of this medium in long‐term preservations of skin biopsies . However, MM has a limited shelf life and may not be accessible to the clinicians, especially for those who are practicing in resource‐poor settings.…”

Section: Discussionmentioning

confidence: 99%

“…In such situations, it is imperative to transport the specimens to the referral laboratory in an appropriate medium which can preserve the tissue bound immunoreactants. Michel's medium (MM) is widely used as a transport medium for DIF studies . However, this medium may not be readily available to physicians working in settings with resource constraints.…”

Section: Introductionmentioning

confidence: 99%

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A comparative study of Michel's medium versus honey as a transport medium for skin specimens prior to direct immunofluorescence microscopy and antigen mapping

et al. 2019

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Background: Michel's medium (MM) is currently the recommended transport medium for skin biopsy specimens prior to direct immunofluorescence (DIF) microscopy.Objective: To compare the utility of honey with that of MM as a transport medium for skin biopsy specimens used for DIF and antigen mapping.Methods: Group I consisted of 45 freshly-taken skin specimens earmarked for DIF testing. It was divided into three groups (A, B and C), each containing 15 specimens.Biopsy specimens were sliced into two, one each for MM and honey. Samples in group A were processed at the end of week 1 while those in group B and C were processed at the end of weeks 2 and 4, respectively. Group II consisted of five specimens of epidermolysis bullosa (EB) which was further divided into three groups; two specimens were processed for antigen mapping at the end of week 1, while others were processed at the end of week 2 (two specimens) and 4 (one specimen).Results: Sensitivity of honey as a transport medium for skin biopsy specimens was 100%, 92.6% and 53.8% at weeks 1, 2 and 4, respectively. The antigen mapping was positive in all specimens.Conclusion: Utility of honey was comparable to MM for DIF samples tested at weeks 1 and 2 but was lower at week 4. K E Y W O R D Santigen mapping, basement membrane zone, direct immunofluorescence, honey, immunopathology, Michel's medium, pemphigus, transport medium

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Section: Discussionsupporting

confidence: 90%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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A comparative study of Michel's medium versus honey as a transport medium for skin specimens prior to direct immunofluorescence microscopy and antigen mapping

et al. 2019

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“…Another disadvantage of saline might be, from a histopathological point of view, morphological disturbances such as hydropic degeneration [19], and splitting at the dermo-epidermal junction, not found with Michel's fixative [6]. That is why saline is not suitable for antigen mapping in the diagnosis of genetic diseases [20]. Neither are biopsies kept in saline suited for immuno-electron microscopy [5,6,20].…”

Section: Discussionmentioning

confidence: 99%

“…That is why saline is not suitable for antigen mapping in the diagnosis of genetic diseases [20]. Neither are biopsies kept in saline suited for immuno-electron microscopy [5,6,20]. However, for the diagnosis of autoimmune and immune complex-mediated diseases by DIF, it is not optimal morphology that counts, but the low detection threshold of immunoreactants.…”

Section: Discussionmentioning

confidence: 99%

Enhanced diagnostic immunofluorescence using biopsies transported in saline

et al. 2004

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BackgroundThe demonstration of tissue-bound immunoreactants by direct immunofluorescence microscopy (DIF) is a valuable parameter in the diagnosis of various autoimmune and immunecomplex-mediated skin diseases. For preservation of tissue-bound immunoreactants, biopsies are usually fresh-frozen in liquid nitrogen or transported in Michel's fixative. But even optimally preserved tissue specimens are no guarantee for the correct diagnosis by DIF, especially when weak to moderate IgG fluorescence of the epidermal basement membrane zone is involved. In such cases false negative results are easily obtained due to the relatively high dermal "background" fluorescence produced by polyclonal anti-human IgG fluorescein conjugates.MethodsIn the present study we have compared the use of normal saline (0.9% NaCl) with liquid nitrogen and Michel's fixative as transport medium for skin biopsies. From 25 patients with an autoimmune skin disease (pemphigus, pemphigoid, lupus erythematosus and vasculitis) four matched skin biopsies were obtained and transported in either saline for 24 and 48 hours, liquid nitrogen, or Michel's fixative for 48 hours.ResultsDirect IF microscopy showed significant reduction of background fluorescence (p < 0.01) and relatively enhanced desired specific (IgG, IgA) staining in biopsies transported in saline. A conclusive or tentative IF diagnosis was reached in 92% after 24 h saline, 83% after 48 h saline, 68% after freezing in liquid nitrogen, and 62% after 48 h Michel's medium (n = 25).ConclusionsWe conclude that transporting biopsies without freezing in normal saline for 24 hours is an adequate and attractive method for routine IF diagnosis in autoimmune and immune complex-mediated dermatoses. The superior results with saline incubation are explained by washing away of IgG background in dermis and epidermis.

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