Vaccination Safety Update: Macrophagic Myofasciitis

Abstract

We wish to raise awareness of the phenomenon of macrophagic myofasciitis (MMF), which does exist in Germany but has not received much attention. This phenomenon may develop after vaccination. MMF is an acquired inflammatory muscular lesion that manifests focally as round cells located in the perifascicular space while the remaining muscle fibers remain relatively intact. Histopathologically, MMF is characterized by macrophages that are positive for diastase resistant periodic acid-Schiff (PAS) and numerous CD8+ T cells. Tissue necrosis or giant cells are typically not detected. As an expression of lysosomal activity, the macrophages are strongly positive for acidic phosphatase and nonspecific esterase. Electron microscopic studies regularly show numerous needle-shaped structures within the lysosomes of these macrophages. By analyzing a tissue section—so called laser microprobe mass analysis (LAMMA)—the needle-shaped structures can be identified as aluminum hydroxide. In adults it is almost exclusively the left deltoid muscle (‘vaccination muscle’) that is affected, in children almost exclusively the quadriceps. Different working groups, mainly in France, postulate a causal association between MMF, aluminium hydroxide containing vaccines—for example, the hepatitis B, hepatitis A, tetanus toxoid vaccines and systemic clinical symptoms. The clinical spectrum, which may occur even up to 10 years after the vaccination, is unspecific and ranges from myalgias and arthralgias to increased fatigue (1, 2). A comprehensive epidemiological follow-up to establish a possible causal association between focal MMF lesions after vaccination, the use of aluminum hydroxide, and systemic clinical symptoms is required—which, as far as we know, has not been undertaken so far. However—and this is an important message—it is absolutely in no way our intention to question the need for the mentioned vaccinations.