Stratum corneum lipid abnormalities in ichthyosis. Detection by a new lipid microanalytical method

Abstract

Although the biochemical diagnosis of the ichthyoses is still in its infancy, the two recessively inherited types, recessive X-linked ichthyosis (RXLI) and nonbullous congenital ichthyosiform erythroderma (CIE), are accompanied by stratum corneum lipid abnormalities. However, in RXLI, cholesterol sulfate accumulates; in CIE, massive quantities of n-alkanes accumulate. The diagnosis of these disorders has required large quantities of scale for sequential, quantitative thin-layer chromatography (TLC). In this study, we sought to confirm the previously described lipid abnormalities with the use of a rapid, recently developed microchromatographic technique that employs silica gel-coated quartz rods and flame ionization detection (Iatroscan). The cholesterol sulfate content of RXLI (n = 5) scale and the n-alkane content of CIE (n = 8) scale were determined by both TLC and the microchromatographic technique. Less than 10 mg of scale and even single punch biopsy specimens sufficed for the microchromatographic technique, whereas more than 50 mg of scale were required for TLC. Since the microchromatographic technique can rapidly detect diagnostic biochemical abnormalities from readily obtainable, small tissue samples, this method could eventually supplant or supplement standard lipid biochemical techniques for the diagnosis of cutaneous lipidoses.

Stratum corneum lipids in disorders of cornification. Steroid sulfatase and cholesterol sulfate in normal desquamation and the pathogenesis of recessive X-linked ichthyosis.

“…4) (23). t Results of stratum granulosum vs. spinosum/basale in normal epidermis and of stratum corneum vs. stratum granulosum or stratum spinosum/basale in RXLI, are statistically significant (P < 0.01, < 0.05, respectively).…”

Neutral lipid storage disease with ichthyosis: Lipid content and metabolism of fibroblasts

“…Lipids were extracted as previously described (Williams et al, 1985a). Quantification of lipids was performed by two methods: thin layer chromatography (TLC) followed by lipid extraction and weighing (Elias et al, 1979) and quartz rod microchromatography-flame ionization (Iatroscan ~) (Brown et al, 1984). The distribution of neutral lipid classes and determination of total polar lipids was determined using the Iatroscan R. This method offers the advantages of analysing complex tipids from small amounts of starting material and compared favourably with other methods of analysis (Rao et al, 1985;Kramer et al, 1985).…”

Free sterol metabolism and low density lipoprotein receptor expression as differentiation markers of cultured human keratinocytes

“…For quantitation of the small amounts of lipid in these cultures, we employed quartz rod microchromatography (Ackman, 1981;Brown et al, 1984). Lipids were dried down under nitrogen gas and resuspended in warm chloroform:methanol (2:1, vols) to a final lipid concentration of about 20 pg/pL.…”