Cytokines and T-cell responses in superantigen-related glomerulonephritis following methicillin-resistant Staphylococcus aureus infection.
BACKGROUND
We have previously reported that 10 patients who developed glomerulonephritis (GN) in association with methicillin-resistant Staphylococcus aureus (MRSA) infection showed a marked increase in DR+CD4+ and DR+CD8+ subsets of T cells and in T cells expressing several T-cell receptor (TCR) V beta+cells, perhaps representing V beta-specific T-cell activation by MRSA-derived superantigens (Kidney Int 1995; 47: 207-216). In this study we examine cytokine levels, T-lymphocyte subsets, natural killer NK cells, memory T cells, and the expression of IL-2 receptors in order to better understand the role of bacterial superantigens and cytokines in the pathogenesis of MRSA-associated GN.


METHODS
Twenty-two patients with MRSA infection who later developed GN caused by staphylococcal enterotoxin were evaluated immunologically in comparison with patients whose MRSA infection was not followed by GN (non-GN group) and normal individuals.


RESULTS
Among peripheral lymphocytes, the frequency of T cells expressing several TCR V betas, especially V beta 5-family TCR, was higher in the GN group than in both the non-GN group and the normal healthy control group. GN patients also showed increased serum levels of several cytokines, including tumour necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), IL-2, IL-6, IL-8, and IL-10, which have been implicated in the onset of nephritis. Memory cells, and IL-2 receptors also were elevated in the GN group.


CONCLUSIONS
These results suggest that T cells activated by MRSA-derived staphylococcal enterotoxins and subsequent production of cytokines may play an important role in the pathogenesis of MRSA-associated GN.
Department of Internal Medicine, Institute of Clinical Medicine, University of Tsukuba, Ibaraki, Japan.
K
K
Yoh
M
M
Kobayashi
N
N
Yamaguchi
K
K
Hirayama
T
T
Ishizu
S
S
Kikuchi
S
S
Iwabuchi
K
K
Muro
S
S
Nagase
K
K
Aoyagi
M
M
Kondoh
K
K
Takemura
K
K
Yamagata
A
A
Koyama
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016207:Cytokines / Q000097:blood; D005260:Female; D005921:Glomerulonephritis / Q000276:immunology* / Q000382:microbiology* / Q000503:physiopathology; D006801:Humans; D016131:Lymphocyte Subsets / Q000473:pathology; D008297:Male; D016106:Methicillin Resistance; D008875:Middle Aged; D013203:Staphylococcal Infections / Q000503:physiopathology*; D013211:Staphylococcus aureus / Q000502:physiology*; D018089:Superantigens / Q000276:immunology*; D013601:T-Lymphocytes / Q000473:pathology
D016207:Cytokines; D018089:Superantigens