Examining clinical similarities between myalgic encephalomyelitis/chronic fatigue syndrome and d -lactic acidosis: a systematic review

Table 1 d-Lactic acidosis case reports screened for qualitative synthesis

Episode code #	References	Included	Reasons for exclusion
1	[20]	N	d-Lactate measurement not specified
2	[17]	N	Plasma d-lactate within normal range
3	[21]	N	d-Lactate measurement not specified
4	[22]	Y
5	[23]	N	d-Lactate measurement not specified
6	[24]	Y
7	[25]	N	d-Lactate not d-la; No comparison between d-lactate and neurological symptoms
8	[26]	Y
9	[27]	Y
10	[28]	Y
11	[29]	Y
12a and 12b	[30]	Y
13	[31]	Y
14	[32]	Y
15	[33]	Y
16₁ and 16₂	[34]	Y
17	[35]	Y
18	[36]	Y
19	[37]	Y
20	[38]	Y
21	[39]	Y
22	[15]	N	d-Lactate levels not presented in relation to neurological symptoms
23	[40]	Y
24	[41]	Y
25	[42]	Y
26*	[43]	Y
27	[44]	Y
28	[45]	Y
29	[46]	Y
30	[47]	Y
31	[48]	Y
32	[49]	N	Unable to obtain full-text
33	[50]	Y
34₁ and 34₂	[51]	Y
35	[52]	Y
36*	[53]	Y
37	[54]	Y
38	[55]	N	Neurological symptoms not specified
39*	[56]	Y
40	[57]	Y
41	[58]	Y
42*	[59]	Y
43	[60]	Y
44	[11]	Y
45	[61, 62]	N	Same case for both references; d-lactate levels not specified
46	[63]	N	d-Lactate not measured
47a and 47b	[64]	Y
48	[65]	Y
49	[66]	Y
50	[67]	Y
51a and 51b	[68]	Y
52	[69]	Y
53	[70]	Y
54	[71]	N	Unable to obtain English full-text
55	[72]	Y
56	[73]	Y
57	[74]	Y
58a and 58b	[75]	Y
59	[76]	Y
60	[77]	Y
61	[78]	N	d-Lactate measurement not specified
62	[79]	Y
63	[80]	N	Neurological symptoms not specified
64	[16]	Y
65	[81]	Y
66	[82]	Y
67	[83]	N	d-Lactate only measured during intervention

Subscript numbers (₁ and ₂) indicate separate episodes for the same patient. The letters a and b identify different patient cases reported in the same reference. Episodes from non-SBS patients are marked with an asterisk. Episodes included in qualitative synthesis simultaneously reported at least one high D-lactate level (from blood or urine analysis) and documented neurological symptoms