Transmission of amyloid-β protein pathology from cadaveric pituitary growth hormone

Abstract

We previously reported¹ the presence of amyloid-β protein (Aβ) deposits in individuals with Creutzfeldt-Jakob disease (CJD) who had been treated during childhood with human cadaveric pituitary-derived growth hormone (c-hGH) contaminated with prions. The marked deposition of parenchymal and vascular Aβ in these relatively young individuals with treatment-induced (iatrogenic) CJD (iCJD), in contrast to other prion-disease patients and population controls, allied with the ability of Alzheimer's disease brain homogenates to seed Aβ deposition in laboratory animals, led us to argue that the implicated c-hGH batches might have been contaminated with Aβ seeds as well as with prions. However, this was necessarily an association, and not an experimental, study in humans and causality could not be concluded. Given the public health importance of our hypothesis, we proceeded to identify and biochemically analyse archived vials of c-hGH. Here we show that certain c-hGH batches to which patients with iCJD and Aβ pathology were exposed have substantial levels of Aβ₄₀, Aβ₄₂ and tau proteins, and that this material can seed the formation of Aβ plaques and cerebral Aβ-amyloid angiopathy in intracerebrally inoculated mice expressing a mutant, humanized amyloid precursor protein. These results confirm the presence of Aβ seeds in archived c-hGH vials and are consistent with the hypothesized iatrogenic human transmission of Aβ pathology. This experimental confirmation has implications for both the prevention and the treatment of Alzheimer's disease, and should prompt a review of the risk of iatrogenic transmission of Aβ seeds by medical and surgical procedures long recognized to pose a risk of accidental prion transmission^2,3.

Extended Data Fig. 1 |. Time course of CAA and Aβ deposition in control- and AD-brain-inoculated App^NL-F/NL-F mice.

Mice were inoculated with either control-brain homogenates (a–c, g–i, m–o, s–u) or AD-brain homogenates (d–f, j–l, p–r, v–x) and culled at the stated times. Aβ deposition was assessed on sagittal sections (a, d, g, j, m, p, s, v). CAA (b, e, h, k, n, q, t, w) and cerebellar deposition (c, f, i, l, o, r, u, x) were evident only in AD-brain-inoculated animals. Boxes denote areas magnified to the right. Scale bars represent 1.4 mm for whole sections (a, d, g, j, m, p, s, v), 25 µm for CAA (b, e, h, k, n, q, t, w), and 50 µm for the cerebellar region (c, f, i, l, o, r, u, x).

Extended Data Fig. 2 |. Aβ plaques and CAA in App^NL-F/NL-F mice following inoculation with c-hGH preparations.

App^NL-F/NL-F mice were inoculated with c-hGH batch HWP 42 (a, c–f, k–n) or HWP 51 (b, g–j, o–r) and culled after 240 days. Aβ deposition was assessed on sagittal sections (a, b). Black and red boxes denote areas magnified to better show cerebellar Aβ deposits (c–j) and CAA (k–r), respectively, in the middle and lower panels. Scale bars represent 1.1 mm for whole sections (a, b) and 50 µm for the cerebellar region and CAA (c–r).

Fig. 1 |. Quantification of vessels with CAA in App^NL-F/NL-F mice following inoculation with Alzheimer’s or control human brain, vehicle alone, or recombinant or cadaveric human growth hormone.

There were highly significant differences between vehicle (PBS)-inoculated mice and those inoculated with either AD brain homogenates or c-hGH preparations (PBS, n = 25; AD1, n = 15; PBS versus AD1, P < 0.0001; AD2, n = 15; PBS versus AD2, P < 0.0001; AD3, n = 14; PBS versus AD3, P < 0.0001; c-hGH HWP 42, n = 10; PBS versus HWP 42, P < 0.0001; c-hGH HWP 51, n = 8; PBS versus HWP 51, P < 0.0001; one-way analysis of variance (ANOVA) followed by Dunnett’s multiple comparison test). There were no significant differences between PBS-inoculated mice and those inoculated with control human brain homogenate or rec-hGH (PBS, n = 25; control brain, n = 15, PBS versus control brain, P = 0.99; rec-hGH, n = 5, PBS versus rec-hGH, P = 0.99). Data are expressed as means ± standard deviation; n = number of mice per group.

Fig. 2 |. Quantification of cerebellar plaque area in App^NL-F/NL-F mice inoculated with Alzheimer’s or control human brain, vehicle alone, or recombinant or cadaveric human growth hormone.

The area covered by plaques is expressed as a percentage of the total area: a, following inoculation with PBS, control normal brain or AD brain; b, following inoculation with PBS, control human brain, rec-hGH or c-hGH. There was no significant difference between PBS-inoculated, control-brain-inoculated or rec-hGH-inoculated mice (PBS, n = 25; control brain, n = 15; PBS versus control brain, P = 0.99; rec-hGH, n = 5; PBS versus rec-hGH, P > 0.99). However, there are significant differences between PBS-inoculated and AD- or c-hGH-inoculated mice (PBS, n = 25; AD1, n = 15; PBS versus AD1, P = 0.007; AD2, n = 15; PBS versus AD2, P < 0.0001; AD3, n = 14; PBS versus AD3, P = 0.0002; c-hGH HWP 42, n = 10; PBS versus HWP 42, P < 0.0001; c-hGH HWP 51, n = 8; PBS versus HWP 51, P = 0.002; one-way ANOVA followed by Dunnett’s multiple comparison test). Data are expressed as means ± standard deviation.

Fig. 3 |. Aβ plaque deposition and CAA in App^NL-F/NL-F mice following inoculation with AD or control brain.

a–f, App^NL-F/NL-F mice were inoculated with either human control brain (a–c; n = 15 mice) or AD brain (d–f; n = 44 mice) homogenates and culled after 240 days. Aβ deposition was assessed on sagittal sections (a, d). CAA (b, e) and cerebellar deposition (c, f) were evident only in AD-brain-inoculated animals. Boxes denote areas magnified in the middle and right panels. Scale bars represent 1.5 mm for whole sections (a, d), 25 µm for CAA (b, e) and 50 µm for the cerebellar region (c, f).

Fig. 4 |. Aβ plaque deposition and CAA in App^NL-F/NL-F mice following inoculation with cadaveric or recombinant growth hormone preparations.

a–i, App^NL-F/NL-F mice were inoculated with rec-hGH (a–c; n = 5 mice), c-hGH batch HWP 42 (d–f; n = 10 mice) or c-hGH batch HWP 51 (g–i; n = 8 mice) and culled after 240 days. Aβ deposition was assessed on sagittal sections (a, d, g). CAA (b, e, h) and cerebellar deposition (c, f, i) were evident in c-hGH- but not rec-hGH-inoculated animals. Boxes denote areas magnified in the middle and right columns. Scale bars represent 1.7 mm for whole sections (a, d, g), 25 µm for CAA (b, e, h), and 50 µm for cerebellar regions (c, f, i).