Autologous whole blood (AWB) therapy is a treatment where a patients blood is first drawn from a vein and then (unmodified or treated in various bizarre ways) reinjected intra-muscularly. This sounds barmy, not least because there is no remotely plausible mode of action. Nonetheless, the therapy is popular in some countries (like Germany, where it is practised by many doctors and Heilpraktikers) and recommended for all sorts of illnesses, particularly for strengthening the immune system and fend off infections.
I have personally used it quite a bit and even conducted the first but very small double-blind, placebo-controlled RCT of AWB therapy which showed promising results. Now two systematic reviews of AWB therapy have become available almost simultaneously.
The first systematic review included our plus 7 more clinical studies. The authors included all prospective controlled trials concerning intra-muscular AWB therapy with the exception of trials using oxygenated, UV radiated or heated blood. Information was extracted on the indication, design, additions to AWB and outcome. Full texts were screened for information about the effector mechanisms.
Eight trials met their inclusion criteria. In three controlled trials with patients suffering from atopic dermatitis and urticaria, AWB therapy showed beneficial effects. In five randomized controlled trials (RCTs), two of which concerned respiratory tract infections, two urticaria and one ankylosing spondylitis, no efficacy could be found. A quantitative assessment was not possible due to the heterogeneity of the included studies. The authors found only 4 controlled trials with sample sizes bigger than 37 individuals per group. Only one study investigated the effector mechanisms of AWB.
The German authors concluded that there is some evidence for efficacy of AWB therapy in urticaria patients and patients with atopic eczema. Firm conclusions can, however, not be drawn. We see a great need for further RCTs with adequate sample sizes and for investigation of the effector mechanisms of AWB therapy.
The second systematic review had a slightly different focus in that it assessed AWB therapy as well as autologous serum therapy (AST) for patients suffering from chronic spontaneous urticaria (CSU). Its authors managed to include 8 clinical trials. AST was not more effective than the placebo treatment in alleviating CSU symptoms at the end of treatment (p = .161), and AWB injection was also not more effective in response rates than the placebo at the end of follow-up (p = .099). Furthermore, the efficacy of AST or AWB injection for CSU and the ASST status were not significantly related. No remarkable adverse events were recorded during therapy.
The Taiwanese authors concluded that their meta-analysis suggested that AWB therapy and AST are not significantly more effective in alleviating CSU symptoms than the placebo treatment.
These somewhat contradictory conclusions will confuse most readers. Personally, I think that caution is well-justified. The trials are mostly flawed, and even our positive study (which received the highest possible quality marks by the authors of the first review) can in no way be definitive, because it was far too small for allowing firm conclusions.
Yet, despite all this, I do think that AWB therapy merits further study.