Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0031350 (pharyngitis)
 2,405 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Streptococcus pyogenes, or group A Streptococcus, is one of the most frequent causes of pharyngitis and skin infections in humans. Many virulence mechanisms have been suggested to be involved in the infectious process. Among them is the binding to the bacterial cell surface of the complement regulatory proteins factor H, factor H-like protein 1 (FHL-1), and C4b-binding protein. Previous studies indicate that binding of these three regulators to the streptococcal cell involves the M protein encoded by the emm gene. M-type 18 strains are prevalent among clinical isolates and have been shown to interact with all three complement regulators simultaneously. Using isogenic strains lacking expression of the Emm18 or the Enn18 proteins, we demonstrate in this study that, in contradistinction to previously described S. pyogenes strains, M18 strains bind the complement regulators factor H, FHL-1, and C4b-binding protein through two distinct cell surface proteins. Factor H and FHL-1 bind to the Emm18 protein, while C4BP binds to the Enn18 protein. We propose that expression of two distinct surface structures that bind complement regulatory proteins represents a unique adaptation of M18 strains that enhances their resistance to opsonization by human plasma and increases survival of this particular S. pyogenes strain in the human host. These new findings illustrate that S. pyogenes has evolved diverse mechanisms for recruitment of complement regulatory proteins to the bacterial surface to evade immune clearance in the human host.
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PMID:Interaction between complement regulators and Streptococcus pyogenes: binding of C4b-binding protein and factor H/factor H-like protein 1 to M18 strains involves two different cell surface molecules. 1555 85

Factor H deficiency is responsible for thrombotic microangiopathy (TMA) via uncontrolled activation of the alternative pathway of the complement system. Ocular TMA has never been reported in patients with factor H abnormalities. A male patient with congenital homozygote factor H deficiency reached end-stage renal disease at the age of 10 years. Hemodialysis was uneventful for 3 years, when, suddenly, unilateral ocular pain and blurred vision occurred while he had febrile pharyngitis. Ophthalmologic examination found vitreous bleeding, elevated ocular pressure, choroidal hemorrhage (ultrasound biomicroscopy) and retinal ischemia (fluorescein angiography). C-reactive protein concentration was increased, while haptoglobin levels remained normal. We suspected that TMA due to factor H deficiency was responsible for the ocular manifestations and immediately initiated daily plasma exchanges (PEs) with fresh frozen plasma (FFP) for 10 days followed by three sessions per week. Factor H serum level increased from 6% to 82%, and C3 level normalized. Progressively, ocular pain decreased, and visual acuity and ophthalmologic findings showed improvement. When there is permanent activation of the alternative pathway in patients with end-stage renal disease (ESRD), the search for secondary targets might be of interest. In nephrectomized patients, no biological parameter can predict isolated ocular TMA. Early ophthalmologic investigation and substitution of factor H via FFP may avoid irreversible damage.
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PMID:Ocular involvement in hemolytic uremic syndrome due to factor H deficiency--are there therapeutic consequences? 1761 7