Correction: SMPDL3B a novel biomarker and therapeutic target in myalgic encephalomyelitis

Correction: Journal of Translational Medicine (2025) 23:748. 10.1186/s12967-025-06829-0

Following publication of the original article [1] it was reported that there was an error in the caption of Fig. 2 and in the illustration of Fig. 4. The correct and incorrect versions of both are given in this Correction, and the original article has been updated.

Incorrect Fig. 2 caption

Influence of covariates on plasma SMPDL3B levels and symptom severity in ME patients. a Plasma levels of SMPDL3B in ME patients (n = 249) and healthy controls (n = 63) from the Canadian cohort. Plasma SMPDL3B levels in Canadian cohort, stratified by SMPDL3B levels using a threshold of 30 ng/mL (n = 118 and n = 131), showing the physical scores of SF-36 questionnaire (b), reduced activity scores of MFI-20 questionnaire (c), PEM scores of DSQ questionnaire (d), severity scores of MFI-20 questionnaire (e), cognitive exhaustion score of DPEMQ questionnaire (f), pain or aching in your muscles score of DSQ questionnaire (g), and the bladder problems score of DSQ questionnaire (h). i Plasma levels of SMPDL3B in different groups of patients with ME from the Norwegian cohort grouped by symptom severity (n = 16 for mild, n = 40 for mild/moderate, n = 41 for moderate, n = 22 moderate/severe and n = 21 severe). Disease severity was determined based on clinical assessments incorporating standardized and trial-specific questionnaires. j Plasma SMPDL3B levels in ME Canadian, ME Norwegian and healthy control female participants (n = 208, n = 119 and n = 33 respectively) and males (n = 41, n = 22 and n = 30 respectively). k Plasma concentrations of SMPDL3B in Canadian female ME participants across different age groups (n = 16 for 18–30 years, n = 97 for 31–50 for years, n = 95 for 51 years and up). l Plasma concentrations of SMPDL3B in Norwegian female ME participants across different age groups (n = 37 for 18–30 years, n = 65 31–50 for years, n = 16 for 51 years and up). m Plasma levels of SMPDL3B in Canadian female participants with or without oral contraceptive use (n = 176 and n = 32 respectively). n Plasma levels of SMPDL3B in Norwegian female participants with or without oral contraceptive use (n = 88 and n = 31 respectively). An unpaired T test was performed when comparing two groups. For comparisons between two groups, the Mann–Whitney U test was used. For comparisons involving more than two groups, the Kruskal–Wallis test was performed, followed by Dunn’s post hoc test with multiple comparison correction where appropriate. Differences were found to be significant at *P < 0.05, **P < 0.01, *** P-value < 0.001 and ****P < 0.0001.

Correct Fig. 2 caption

Influence of covariates on plasma SMPDL3B levels and symptom severity in ME patients. (a) Plasma levels of SMPDL3B in ME patients (n = 249) and healthy controls (n = 63) from the Canadian cohort. (b) Plasma levels of SMPDL3B in different groups of patients with ME from the Norwegian cohort grouped by symptom severity (n = 16 for mild, n = 40 for mild/moderate, n = 41 for moderate, n = 22 moderate/severe and n = 21 severe). Disease severity was determined based on clinical assessments incorporating standardized and trial-specific questionnaires. (c) Plasma SMPDL3B levels in ME Canadian, ME Norwegian and healthy control female participants (n = 208, n = 119 and n = 33 respectively) and males (n = 41, n = 22 and n = 30 respectively). (d) Plasma concentrations of SMPDL3B in Canadian female ME participants across different age groups (n = 16 for 18–30 years, n = 97 for 31–50 for years, n = 95 for 51 years and up). (e) Plasma concentrations of SMPDL3B in Norwegian female ME participants across different age groups (n = 37 for 18–30 years, n = 65 31–50 for years, n = 16 for 51 years and up). (f) Plasma levels of SMPDL3B in Canadian female participants with or without oral contraceptive use (n = 176 and n = 32 respectively). (g) Plasma levels of SMPDL3B in Norwegian female participants with or without oral contraceptive use (n = 88 and n = 31 respectively). An unpaired T test was performed when comparing two groups. For comparisons between two groups, the Mann–Whitney U test was used. For comparisons involving more than two groups, the Kruskal–Wallis test was performed, followed by Dunn’s post hoc test with multiple comparison correction where appropriate. Differences were found to be significant at *P < 0.05, **P < 0.01, *** P-value < 0.001 and ****P < 0.0001.

Incorrect Fig. 4

Correct Fig. 4

Fig. 4.

Vildagliptin and Saxagliptin Modulate SMPDL3B Expression and Membrane Anchoring in PBMCs. The molecular structures of vildagliptin, saxagliptin and linagliptin are shown in panels a, b and c respectively. The data are displayed as a histogram with individual data points overlaid with mean and standard error of the mean (SEM). d Gene expression levels of SMPDL3B and PLCXD1 in PBMCs treated with increasing doses of vildagliptin. e Gene expression levels of SMPDL3B and PLCXD1 in PBMCs treated with increasing doses of saxagliptin. f Gene expression levels of SMPDL3B and PLCXD1 in PBMCs treated with increasing doses of linagliptin. Gene expression was measured using RT-qPCR with TaqMan probes and normalized to the housekeeping gene GAPDH. g Levels of membrane-bound SMPDL3B in monocytes after treatment with increasing doses of vildagliptin, saxagliptin and linagliptin (NT (no treatment), 25 µM, 50 µM, and 100 µM). Membrane-bound SMPDL3B levels were quantified using flow cytometry, with gating strategies applied to identify monocyte populations. h Levels of membrane-bound SMPDL3B in lymphocytes under the same conditions. i Levels of soluble PI-PLC in cell culture supernatant of PBMCs following treatment with increasing doses of vildagliptin, saxagliptin and linagliptin. Soluble SMPDL3B and PI-PLC levels were quantified using ELISA. T test was used when comparing two groups. For comparisons between two groups, the Mann–Whitney U test was used. For comparisons involving more than two groups, the Kruskal–Wallis test was performed, followed by Dunn’s post hoc test with multiple comparison correction where appropriate. Differences were found to be significant at *P < 0.05, **P < 0.01, ***P-value < 0.001 and ****P-value < 0.0001