Purpuric phototherapy-induced eruption in transfused neonates: relation to transient porphyrinemia

OBJECTIVE

Blue light phototherapy is commonly administered to neonates as treatment of indirect hyperbilirubinemia, often in conjunction with blood transfusions to treat hemolytic anemia. We observed a distinctive cutaneous complication of phototherapy in six neonates with hyperbilirubinemia.

METHODOLOGY

We studied the clinical and histologic characteristics of the eruption, as well as the porphyrin levels in affected neonates. Five of the patients had erythroblastosis fetalis; the other had profound anemia from twin-twin transfusion. All of the neonates developed purpuric patches at sites of maximal exposure to the phototherapy lights, with dramatic sparing at shielded sites within 24 hours after initiation of the phototherapy. On discontinuation of phototherapy, all eruptions cleared within 1 week. Examination of skin biopsy sections showed purpura without significant inflammation or keratinocyte necrosis. Plasma porphyrins (copro- and proto-) were elevated in the two patients in which they were assessed.

CONCLUSIONS

The distribution of the eruption in areas exposed to light and presence of circulating porphyrins suggest that porphyrinemia may underlie the light-induced purpuric eruption. Additional studies will be required to determine definitively the mechanisms of both the purpuric phototherapy-induced eruption and the development of increased blood porphyrin levels in these transfused neonates.

Localized facial flushing in infancy. Auriculotemporal nerve (Frey) syndrome

BACKGROUND

Patients with auriculotemporal nerve syndrome (Frey syndrome) have facial flushing, sweating, or both localized to the distribution of the auriculotemporal nerve that occurs in response to gustatory stimuli. In adults, the syndrome usually results from surgical injury or trauma to the parotid gland. The condition is rare in infants, but usually manifests during infancy with the introduction of solid food, thus leading to the misdiagnosis of food allergy by physicians unfamiliar with the syndrome.

OBSERVATIONS

We describe 8 children with auriculotemporal nerve syndrome who manifested with flushing only. The reaction was erroneously attributed to food allergy in most cases. Six of the 8 patients were delivered with forceps assistance. The remaining 2 patients, with disease onset during the first 3 months of life, had bilateral involvement without known trauma.

CONCLUSIONS

Auriculotemporal nerve syndrome may manifest during infancy as flushing with eating food. In contrast to the syndrome in adults, gustatory sweating is rarely associated. The known use of forceps to assist in the delivery of at least 14 of the 28 previously reported pediatric cases and in 6 of our 8 patients suggests that trauma to the parotid region may be responsible for the condition in most infants, as it is in adults. Auriculotemporal nerve syndrome in infancy should be recognized as a benign condition that often resolves spontaneously. Treatment is ineffective and unnecessary.

Consequences of seven novel mutations on the expression and structure of keratinocyte transglutaminase

We report the molecular characterization of seven new keratinocyte transglutaminase mutations (R315C, S358R, V379L, G473S, R687C, deletion Delta679-696, R127Stop) found in lamellar ichthyosis patients. Arg-315, Ser-358, Val-379, and Gly-473 are highly conserved residues in transglutaminases while Arg-687 and Delta679-696 are not. All mutations strongly decreased transglutaminase activity and protein levels. The mutation R127Stop diminished the amount of mRNA. Structural analysis of these mutations based on the factor XIII A-subunit crystal structure demonstrated that Arg-315, Ser-358, Val-379, and Gly-473 are located in the catalytic core domain, and Arg-687 and the deletion are in the beta-barrel domains. The side chains of amino acids Arg-315, Ser-358, and Gly-473 make ionic and hydrogen bonds important for folding and structural stability of the enzyme but are not directly involved in catalysis. Val-379 is two amino acids away from the active site cysteine, and its change into leucine disturbs the active site structure. The decreased activity and protein level after expression of the R687C and Delta679-696 TGK cDNA in TGK negative keratinocytes excluded that they are polymorphisms. These results identify important amino acids in the central core domain of transglutaminases and show that the C-terminal end influences the structural and functional integrity of TGK.

Pulmonary hemorrhage: an often fatal complication of Henoch-Schoenlein purpura

Two patients with Henoch-Schoenlein purpura developed pulmonary hemorrhage. One patient survived after treatment with intravenous methylprednisolone and cyclophosphamide; the other patient died from cardiopulmonary arrest before therapy could be initiated. Although rare, pulmonary complications of Henoch-Schoenlein purpura can lead to rapid demise unless immediate supportive treatment is initiated.

The genetic basis of hereditary blistering disorders

Inherited blistering disorders have been classified by inheritance pattern, ultrastructural morphology and level of skin cleavage, and immunofluorescence detection of cutaneous antigens. During the past 5 years, investigators have discovered the molecular bases for the major inherited blistering disorders, epidermolytic hyperkeratosis, epidermolysis bullosa simplex, epidermolytic palmoplantar keratoderma, junctional epidermolysis bullosa, and dystrophic forms of epidermolysis bullosa. In addition to providing answers to patients about the underlying mechanisms of these devastating blistering disorders, the discoveries have provided insight into the function of several cutaneous proteins and have led to the ability to diagnose prenatally these lifelong conditions through genetic analysis in affected families.

Pigmentary anomalies in the multiple lentigines syndrome: Is it distinct from LEOPARD syndrome?

We observed 2 families with 26 individuals affected by multiple lentigines syndrome (MLS). All patients had extensive generalized lentigines, including in the axillary and inguinal regions, diffuse hyperpigmentation, hypopigmented patches, and hyperpigmented patches, many of which appeared clinically to be cafe au lait spots. Multiple lentigines syndrome should be considered in the differential diagnosis of multiple cafe au lait spots in children, particularly since the spots are usually present before the lentigines develop and may be clinically indistinguishable from the cafe au lait spots of neurofibromatosis. No significant noncutaneous features occurred in the two families with three generations of affected individuals, suggesting that MLS is a distinct entity. However, patients with the noncutaneous abnormalities of the LEOPARD syndrome have been described in families in which most members had pigmentary lesions only. Therefore, patients with multiple lentigines should be evaluated for noncutaneous abnormalities, particularly hearing loss and cardiac anomalies. Similarly, until investigators demonstrate lack of genetic linkage between MLS and LEOPARD syndrome, genetic counseling of patients affected by the cutaneous features of the former should include the potential for noncutaneous features in offspring.

Prenatal diagnosis for recessive dystrophic epidermolysis bullosa in 10 families by mutation and haplotype analysis in the type VII collagen gene (COL7A1)

BACKGROUND

Epidermolysis bullosa (EB) is a group of heritable diseases that manifest as blistering and erosions of the skin and mucous membranes. In the dystrophic forms of EB (DEB), the diagnostic hallmark is abnormalities in the anchoring fibrils, attachment structures beneath the cutaneous basement membrane zone. The major component of anchoring fibrils is type VII collagen, and DEB has been linked to the type VII collagen gene (COL7A1) at 3p21, with no evidence for locus heterogeneity. Due to life-threatening complications and significant long-term morbidity associated with the severe, mutilating form of recessive dystrophic EB (RDEB), there has been a demand for prenatal diagnosis from families with affected offspring.

MATERIALS AND METHODS

Intragenic polymorphisms in COL7A1 and flanking microsatellite markers on chromosome 3p21, as well as detection of pathogenetic mutations in families, were used to perform PCR-based prenatal diagnosis from DNA obtained by chorionic villus sampling at 10-15 weeks or amniocentesis at 12-15 weeks gestation in 10 families at risk for recurrence of RDEB.

RESULTS

In nine cases, the fetus was predicted to be normal or a clinically unaffected carrier of a mutation in one allele. These predictions have been validated in nine cases by the birth of a healthy child. In one case, an affected fetus was predicted, and the diagnosis was confirmed by fetal skin biopsy.

CONCLUSIONS

DNA-based prenatal diagnosis of RDEB offers an early, expedient method of testing which will largely replace the previously available invasive fetal skin biopsy at 18-20 weeks gestation.

Ganglioside GT1b inhibits keratinocyte adhesion and migration on a fibronectin matrix

Highly sialylated gangliosides have been shown to alter cellular adhesion to a fibronectin matrix. The effect of these gangliosides on the adhesion, spreading, and migration of cultured keratinocytes on a fibronectin matrix has not been explored. Ganglioside GT1b significantly prevented attachment of keratinocytes to fibronectin and also detached previously adherent keratinocytes in a concentration-dependent manner without cell toxicity. GT1b did not affect adhesion of keratinocytes to wells coated with laminin, type I or type IV collagen, 804G extracellular matrix, or albumin. GT1b also inhibited keratinocyte migration on fibronectin in a concentration-dependent manner at concentrations as low as 5 nM GT1b, but had no effect on migration of keratinocytes plated on other matrices. GT1b binds to intact fibronectin and to the 120-kD RGDS-containing cell-binding fibronectin fragment, but not to the heparin- or gelatin-binding fragments of fibronectin. Although RGDS competes with GT1b in inhibiting adhesion, GT1b does not diminish binding of keratinocytes to a derivatized RGDS substratum, suggesting that the GT1b effect involves a non-RGDS site in the cell-binding region that modulates RGDS/alpha 5 beta 1 integrin receptor interaction. Through a specific effect on keratinocyte interaction with fibronectin, GT1b may participate in the regulation of cell adhesion and migration on a fibronectin substratum, which are important events during wound healing and the spreading of cutaneous neoplasia.

Inhibitory action of ganglioside GM3 on murine neuroblastoma cell proliferation: modulating effect of fetal calf serum

Exogenous gangliosides have been shown to exert a regulatory influence on the proliferation and differentiation of several cell lines in tissue culture. The effect of ganglioside GM3 on C-1300 murine neuroblastoma (MNB) cell proliferation and the modulating action of fetal calf serum (FCS) concentration in the culture media have been investigated. MNB cells were cultured in DMEM containing 1, 2.5, 5 or 10% FCS, and incubated with GM3 at concentrations ranging from 1.95 to 500 microM. Cell proliferation was assayed 4 days after the addition of GM3 using the CellTiter 96 Non-Radioactive Cell Proliferation Assay. GM3 inhibited MNB cell proliferation in a dose-dependent manner regardless of the FCS concentration in the culture media. However, the magnitude of this inhibitory effect was inversely proportional to the FCS concentration in the culture media. The addition of albumin to MNB cells cultured in DMEM containing 1% FCS exerted no effect on the antiproliferative action of GM3. FACS cell cycle analyses demonstrated that MNB cultured in DMEM containing 1% FCS had a higher proportion of cells in the G0/G1 compartment when compared to those cultured in 10% FCS. The enhanced response of MNB cells to GM3 observed in 1% FCS, may be due to a preferential action on cells in the G0/G1 stage of the cell cycle. These studies have demonstrated that the ganglioside GM3 inhibited MNB cell proliferation in tissue culture and this effect was modulated by FCS concentration in the culture media. Since protein-binding of GM3 by FCS does not appear to be the primary mechanism by which FCS exerts its antagonistic effects, we hypothesize that this may be due to the opposing action of stimulatory growth factors present in FCS.

Chemiluminescence detection of gangliosides by thin-layer chromatography

We describe a method for the detection of gangliosides on thin-layer chromatography plates using enhanced chemiluminescence. In contrast to previously published colorimetric techniques, the use of chemiluminescence of detect antibody binding to gangliosides has increased sensitivity and simplicity. In addition, the use of chemiluminescence lacks the hazards of radioactivity, and produces a permanent record.

Ganglioside GT1b induces keratinocyte differentiation without activating protein kinase C

The altered patterns of expression of gangliosides during density-dependent growth inhibition, oncogenic transformation, and embryogenesis suggest that gangliosides, sialylated membrane glycolipids, may affect cellular proliferation and differentiation. Gangliosides of the "b" pathway of ganglioside synthesis, including GM3, GD3, and GD1b, inhibit the proliferation of cultured keratinocytes without increasing differentiation. We have examined the effect on keratinocyte proliferation and differentiation of supplemental ganglioside GT1b, a more highly sialylated ganglioside of the "b" synthetic pathway that is also present in cultured keratinocytes. In contrast to the lack of effect on differentiation of these other gangliosides, we noted significant induction of keratinocyte differentiation by GT1b, as evidenced by early desmosome formation, and increased cornified envelope formation and expression of involucrin and of the differentiation-specific keratin K1. The addition of GT1b did not cause a shift in intracellular free calcium or alter protein kinase C activity. Alterations in the membrane concentration of ganglioside GT1b, a minor ganglioside component of the keratinocyte membrane, may participate in regulating keratinocyte differentiation.