Juvenile colloid milium. Immunohistochemical and ultrastructural studies.
ABSTRACT A 7-year-old Italian girl with juvenile colloid milium was studied with histological, immunohistochemical, and electron microscopic methods. This patient had a well-documented history of severe sunburn and developed the lesions on the face shortly afterward. Numerous apoptotic keratinocytes were observed in the lower epidermis. These cells began their degeneration with filamentous whorl formation (or filamentous degeneration) of tonofilaments. In the papillary dermis the colloid substance was resolved by the electron microscopy into either wavy, thin filaments derived from the epidermal keratinocytes or typical amyloid filaments. Many desmosomes and gap junctions were found in the colloid substance. Polyclonal antikeratin antibody (DAKO) was positive in the colloid substance, particularly in the parts close to the epidermis. These findings suggested that juvenile colloid milium is different from adult colloid milium despite clinical similarities and that the former belongs to the group of actinic amyloid K, i.e. amyloidoses due to actinic degeneration of keratinocyte and its keratin.
- SourceAvailable from: PubMed Central[show abstract] [hide abstract]
ABSTRACT: Three monoclonal antibodies (AE1, AE2, and AE3) were prepared against human epidermal keratins and used to study keratin expression during normal epidermal differentiation. Immunofluorescence staining data suggested that the antibodies were specific for keratin-type intermediate filaments. The reactivity of these antibodies to individual human epidermal keratin polypeptides (65-67, 58, 56, and 50 kdaltons) was determined by the immunoblot technique. AE1 reacted with 56 and 50 kdalton keratins, AE2 with 65-67 and 56-kdalton keratins, and AE3 with 65-67 and 58 kdalton keratins. Thus all major epidermal keratins were recognized by at least one of the monoclonal antibodies. Moreover, common antigenic determinants were present in subsets of epidermal keratins. To correlate the expression of specific keratins with different stages of in vivo epidermal differentiation, the antibodies were used for immunohistochemical staining of frozen skin sections. AE1 reacted with epidermal basal cells, AE2 with cells above the basal layer, and AE3 with the entire epidermis. The observation that AE1 and AE2 antibodies (which recognized a common 56 kdalton keratin) stained mutually exclusive parts of the epidermis suggested that certain keratin antigens must be masked in situ. This was shown to be the case by direct analysis of keratins extracted from serial, horizontal skin sections using the immunoblot technique. The results from these immunohistochemical and biochemical approaches suggested that: (a) the 65- to 67-kdalton keratins were present only in cells above the basal layer, (b) the 58-kdalton keratin was detected throughout the entire epidermis including the basal layer, (c) the 56-kdalton keratin was absent in the basal layer and first appeared probably in the upper spinous layer, and (d) the 50-kdalton keratin was the only other major keratin detected in the basal layer and was normally eliminated during s. corneum formation. The 56 and 65-67-kdalton keratins, which are characteristic of epidermal cells undergoing terminal differentiation, may be regarded as molecular markers for keratinization.The Journal of Cell Biology 12/1982; 95(2 Pt 1):580-8. · 10.82 Impact Factor
Article: Concerning adult colloid milium.Archives of Dermatology 12/1960; 82:711-6. · 4.79 Impact Factor
- Clinical and Experimental Dermatology 08/1983; 8(4):355-62. · 1.33 Impact Factor