Effect of plasma exchange on cytokines measured by multianalyte bead array in thrombotic thrombocytopenic purpura

Abstract

The serum cytokine profile in thrombotic thrombocytopenic purpura (TTP) has not been extensively characterized. In this pilot study, a novel technique was utilized to evaluate multiple cytokines in patients with idiopathic TTP during a course of plasma exchange (PE). Single serum samples were obtained from five TTP patients before and after each PE. Random sera were obtained from nine healthy volunteers who served as controls. The samples were evaluated for 13 cytokines (IL-1B, IL-2 , IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12, IL-13, IFN-g , GM-CSF, and TNF-a) using the Luminex bead array (LINCOplex) multianalyte detection system that permits simultaneous detection of multiple cytokines from a single sample. Each patient received 4-6 PEs (Cobe Spectra) with 3.0-4.0 L of fresh frozen plasma as replacement fluid. Four of 5 patients received corticosteroids prior to and during PE. The control group did not receive steroids. Baseline values for IL-8 (182.9 vs. 6.5 pg/mL, P < 0.05) and TNF-a (11.4 vs. 0.9 pg/mL, P < 0.001) were significantly higher in TTP patients compared with controls. Other tested cytokines were not significantly different between the two groups. Comparison of cytokine values pre-and post-PE indicate a substantial decrease after each PE. However, cytokines rebounded to abnormal levels by the following day. There was no correlation between cytokines and serum LDH or platelet count. These findings suggest that certain cytokines, particularly IL-8 and TNF-a, are altered in TTP, and this may indicate a direct role in TTP pathogenesis, reflect ongoing tissue injury, or perhaps indicate an inadequate attempt to limit tissue injury.

Synergistic interactions between interferon-γ and TRAIL modulate c-FLIP in endothelial cells, mediating their lineage-specific sensitivity to thrombotic thrombocytopenic purpura plasma–associated apoptosis

“…We also used 1 U/mL (0.1 ng/mL) IFN-␥. This concentration is 5-fold greater than that reported in acute TTP plasmas, 8 but is typical of tissue (lymph node extract) levels found in HIV infection and some healthy individuals. 27 HUVECs and pulmonary MVECs were unaffected by TNF-␣ (1 ng/mL), TRAIL (2 ng/mL), or IFN-␥ (0.1 ng/mL) when used alone (Figure 2; data not shown).…”

“…All have been linked epidemiologically to TTP. 8,20,38,39 HIV is of particular interest in this regard, in terms of the magnitude of its association-1 in 200 patients with untreated HIV disease develop TTP 40 -and the similarities between idiopathic and HIV-linked TTP, including the presence of ADAMTS13 autoantibody and response to plasma exchange. 20,41 Individual cytokine levels in TTP plasmas may be indistinguishable from those of many other disorders, including hepatitis B infection and malignancy, 42 in the absence of a thrombotic microangiopathy.…”

“…1 Plasma levels of TNF-␣ and IL-1 are increased at the onset of disease, with normalization following TTP treatment by plasma exchange. 6,8 In other types of thrombotic microangiopathy, including diarrhea/shigatoxin-associated (D ϩ ) hemolytic uremic syndrome (HUS), significant alterations in these cytokines have not been documented. 9,10 However, levels of IL-1 or TNF-␣ required to induce MVEC apoptosis in vitro are 2-to 3-log-fold greater than those present in TTP plasma.…”

“…TNF-␣, a related cytokine, TNF-related apoptosis-inducing ligand (TRAIL), and another soluble factor up-regulated during the acute phase of TTP, interferon (IFN)-␥, 8 can interact to elicit apoptosis in several cell types. 11,12 Although the levels required still far exceed those present in TTP, such synergy studies offer insight into modulation of cell-specific cytoprotective pathways that might underlie the differential sensitivity of divergent ECs to injury in TTP.…”

“…6,8 In other types of thrombotic microangiopathy, including diarrhea/shigatoxin-associated (D ϩ ) hemolytic uremic syndrome (HUS), significant alterations in these cytokines have not been documented. 9,10 However, levels of IL-1 or TNF-␣ required to induce MVEC apoptosis in vitro are 2-to 3-log-fold greater than those present in TTP plasma.TNF-␣, a related cytokine, TNF-related apoptosis-inducing ligand (TRAIL), and another soluble factor up-regulated during the acute phase of TTP, interferon (IFN)-␥, 8 can interact to elicit apoptosis in several cell types. 11,12 Although the levels required still far exceed those present in TTP, such synergy studies offer insight into modulation of cell-specific cytoprotective pathways that might underlie the differential sensitivity of divergent ECs to injury in TTP.…”