Received Oct 30, 2025
| Type | Name | Manufacturer | Dose | Lot | Route / Site |
|---|---|---|---|---|---|
| COVID19 | COVID19 (COVID19 (PFIZER-BIONTECH)) | PFIZER\BIONTECH | 3 | — | — |
Immune-Mediated Necrotizing Myopathy flared; Immune-Mediated Necrotizing Myopathy flared; This is a literature report for the following literature source(s): A 15-year-old female patient received BNT162b2 (BNT162B2), as dose 3 (booster), single (Batch/Lot number: unknown) for covid-19 immunisation. The patient's relevant medical history included: "Sjogren's disease" (ongoing); "May- Thurner Syndrome" (unspecified if ongoing); "pulmonary embolus" (unspecified if ongoing). The patient's concomitant medications were not reported. Vaccination history included: Pfizer/biontech (DOSE 1), administration date: 2021, for Covid-19 immunization; Pfizer/biontech (DOSE 2), administration date: Jun2021, for Covid-19 immunization, reaction(s): "Immune-Mediated Necrotizing Myopathy". The following information was reported: IMMUNE-MEDIATED MYOSITIS (medically significant), CONDITION AGGRAVATED (medically significant), outcome "unknown" and all described as "Immune-Mediated Necrotizing Myopathy flared". Juvenile idiopathic inflammatory myopathies (JIIMs) are a group of heterogeneous autoimmune disorders affecting skeletal muscle, resulting in acute or subacute onset of symmetric progressive proximal muscle weakness and elevated muscle enzymes JIIMs are rare, with an incidence between 1.6 and 4 cases per million children per year and a prevalence of 2.5 cases per 100,000 children. The most common type of JIIM is juvenile dermatomyositis (JDM) (80% of JIIMs); other JIIMs include amyopathic dermatomyositis, inclusion body myositis, polymyositis, and immune-mediated necrotizing myopathy (IMNM). The etiology of JDM is unclear, but it may result from an autoimmune reaction triggered by environmental factors in genetically susceptible individuals. A 15-year- old female presented to the pediatric emergency department in October 2021 with 2 months of worsening muscle weakness, calf pain, and limited range of arm motion. Other recent symptoms included right hip stiffness, color changes in the fingertips with cold exposure, increasing fatigue, and decreased appetite, along with an unintentional 10-pound weight loss over the past month. Previously active in multiple sports, she was no longer able to participate in any sport and required assistance with activities of daily living. She denied fevers, chills, rashes, difficulty swallowing, or bowel or bladder incontinence. She had received mRNA coronavirus disease 2019 (COVID-19) vaccine (Pfizer/BioNTech) earlier that year, with the second vaccination (June 2021) occurring approximately 7 weeks before the reported onset of symptoms. She had no known recent exposures to COVID-19 or mononucleosis. On initial physical exam, she had normal vital signs and reduced strength in proximal muscles (3/5 at shoulders and hips, 4/5 at elbows and knees, and 5/5 at wrists and ankles). She walked slowly and was unable to rise from a chair without using her arms. The rest of the physical exam, including skin exam, was unremarkable. Initial bloodwork revealed marked elevations in creatine phosphokinase (CK) (28,138), aspartate aminotransferase (928), alanine transaminase (619), lactate dehydrogenase (3152), and urinary myoglobin (> 8750). Inflammatory markers were elevated (C-reactive protein 4.68, erythrocyte sedimentation rate 39), and blood cell counts were normal. The patient's presentation was concerning for viral myositis, rhabdomyolysis, or JIIM. A magnetic resonance imaging (MRI) of the right lower extremity revealed extensive proximal intermuscular and sub-fascial edema, which was consistent with the expected findings seen in JIIM. Additional testing revealed positive antinuclear antibodies (1:1280 titer, cytoplasmic pattern), positive anti-Sjogren's Syndrome antigen A (SSA/Ro), and positive rheumatoid factor (RF). Additional history-taking revealed a recent increase in dental caries and dry mouth, without dry or burning eyes or a history of cheek swelling, concerning for Sjogren's disease. Epstein Bar Virus (EBV) VCA IgG was positive, but EBV IgM and cytomegalovirus PCR were negative. Aldolase was markedly elevated (> 360). She did not have any unexplained fevers, hair loss, oral or nasal ulcers, or joint swelling or stiffness. She did not have recent medication use to suggest drug-induced myopathy. Muscular dystrophies were considered unlikely based on her age and sex. On hospital day 8, the patient experienced sudden-onset chest pain and hemoptysis. Computerized tomography angiogram of the chest revealed a pulmonary embolus. Electrocardiogram, echocardiogram, and high-resolution chest computed tomography were all normal. Pulmonary function testing showed a mixed obstructive and restrictive pattern with normal diffusion capacity for carbon monoxide. MRI/magnetic resonance venogram of the abdomen showed compression of the left common iliac vein, consistent with a diagnosis of May-Thurner Syndrome. Enoxaparin was initiated. The patient's muscle biopsy of the right thigh revealed necrotic fibers with limited inflammatory cells, suggestive of IMNM (Figure 1: Muscle biopsy. Hemotoxylin and eosin stained cryosections magnified 100x (A) and 200x (B) show several necrotic (asterisk) and regenerating muscle fibers (cross). Paraffin section-immunohistochemistry illustrates numerous CD68(+) macrophages (C, thin/red arrows) and rare perivascular CD3(+) T-cells (D, thick/black arrows) within the necrotic fibers). Additional testing showed high-titer anti-signal recognition particle (anti-SRP) antibody (1:61,440) and negative anti-3- hydroxy- 3- methylglutaryl coenzyme A reductase (anti-HMGCR), consistent with a diagnosis of IMNM. She was treated with intravenous immunoglobulin (IVIG) and pulse solumedrol, followed by rituximab and prolonged oral prednisone taper. She was transferred to an inpatient rehabilitation center 22 days after hospitalization with a rolling walker. Two months after hospital discharge, she developed chest pain and cough with blood-tinged mucus and tested positive for COVID-19 for the first time. Repeat CK was increased, but she did not experience worsening muscle weakness and continued with the scheduled prednisone taper. Nonetheless, continued CK elevations prompted initiation of mycophenolate mofetil (later switched to mycophenolic acid due to gastrointestinal intolerance) and an increase in prednisone dose, followed by monthly IVIG infusions. On this regimen, her muscle strength improved, she regained the ability to walk, the CK normalized, and prednisone was again tapered. However, within 1 week after receiving her COVID-19 booster, she experienced worsening fatigue and rapidly worsening proximal muscle weakness, with renewed difficulty lifting her legs and arms, rising from a seated position, and swallowing. There were no symptoms or signs of recurrent COVID-19. Repeat CK in the emergency room was 6311 (up from 167 pre-booster), and she received another pulse of methylprednisolone. She did not require hospitalization at that time. Oral prednisone was increased to 60 mg daily, and she started another course of rituximab soon thereafter. Subsequent lung imaging revealed subpleural reticulation, compatible with interstitial lung disease. Conclusion: Authors report an adolescent girl who developed progressive symptoms of a rare chronic muscle disease, immune-mediated necrotizing myopathy, within 2 months following completion of the primary COVID-19 mRNA vaccination series and who flared within 1 week following booster vaccination. This patient also had clinical features of Sjogren's disease, another rare pediatric condition that has not previously been reported to co-occur with IMNM in children. This unique case raises the hypothesis that the COVID-19 vaccine may, in rare cases, trigger autoimmune muscle disease in susceptible children. More research is needed to better understand the potential mechanistic link between COVID-19 vaccination and autoimmune myositis as a possible vaccine-related adverse event.; Sender's Comments: The events immune-mediated myositis, and condition aggravated are conservatively assessed as related to the suspect drug BNT162B2 based on plausible temporal association but consider also possible contributory effects from medical history of the patient and/or concomitant medications. The impact of this report on the benefit-risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to regulatory authorities, ethics committees and investigators, as appropriate.,Linked Report(s) : US-PFIZER INC-PV202500125702 Same article/drug/patient and different event;
Sjogren's disease
Medical History/Concurrent Conditions: May-Thurner syndrome; Pulmonary embolus
Test Name: alanine transaminase; Result Unstructured Data: Test Result:619; Test Name: Aldolase; Result Unstructured Data: Test Result:Greater than 360; Comments: markedly elevated; Test Name: Anti-Sjogren's Syndrome antigen A (SSA/Ro); Test Result: Positive ; Test Name: high-titer anti-signal recognition particle (anti- SRP) antibody; Result Unstructured Data: Test Result:1:61440; Comments: high- titer; Test Name: antinuclear antibodies; Test Result: Positive ; Comments: 1:1280 titer, cytoplasmic pattern); Test Name: aspartate aminotransferase; Result Unstructured Data: Test Result:928; Test Name: muscle biopsy of the right thigh; Result Unstructured Data: Test Result:revealed necrotic fibers with limited; Comments: inflammatory cells, suggestive of IMNM. Hemotoxylin and eosin stained cryosections magnified 100x (A) and 200x (B) show several necrotic (asterisk) and regenerating muscle fibers (cross). Paraffin section -immunohistochemistry illustrates numerous CD68(+) macrophages (C, thin/red arrows) and rare perivascular CD3(+) T- cells (D, thick/black arrows) within the necrotic fibers.; Test Name: CK; Result Unstructured Data: Test Result:was increased; Test Name: CK; Result Unstructured Data: Test Result:continued CK elevations; Test Name: CK; Result Unstructured Data: Test Result:normalized; Test Name: creatine phosphokinase; Result Unstructured Data: Test Result:28138 IU/l; Comments: marked elevations; Test Name: creatine phosphokinase; Result Unstructured Data: Test Result:6311 IU/l; Comments: up from 167 pre- booster; Test Name: creatine phosphokinase; Result Unstructured Data: Test Result:up from 167 IU/l; Comments: pre- booster; Test Name: lactate dehydrogenase; Result Unstructured Data: Test Result:3152; Test Name: CD68; Test Result: Positive ; Test Name: perivascular CD3; Test Result: Positive ; Test Name: Computerized tomography angiogram of the chest; Result Unstructured Data: Test Result:revealed a pulmonary embolus; Test Name: high- resolution chest CT; Result Unstructured Data: Test Result:normal; Test Name: C- reactive protein; Result Unstructured Data: Test Result:4.68; Test Name: cytomegalovirus PCR; Test Result: Negative ; Test Name: echocardiogram; Result Unstructured Data: Test Result:normal; Test Name: Electrocardiogram; Result Unstructured Data: Test Result:normal; Test Name: EBV IgM; Test Result: Negative ; Test Name: Epstein Bar Virus (EBV) VCA IgG; Test Result: Positive ; Test Name: anti- 3- hydroxy- 3- methylglutaryl coenzyme A reductase (anti-HMGCR); Test Result: Negative ; Test Name: Paraffin section- immunohistochemistry; Result Unstructured Data: Test Result:illustrates numerous CD68(+) macrophages; Comments: (C, thin/red arrows) and rare perivascular CD3(+) T- cells (D, thick/black arrows) within the necrotic fibers.; Test Name: magnetic resonance imaging (MRI) of the right lower extremity; Result Unstructured Data: Test Result:revealed extensive proximal inter muscular and; Comments: subfascial edema, which was consistent with the expected findings seen in JIIM.; Test Name: muscle strength; Result Unstructured Data: Test Result:improved; Test Name: urinary myoglobin; Result Unstructured Data: Test Result:Greater than 8750; Test Name: physical exam; Result Unstructured Data: Test Result:she had normal vital signs and; Comments: reduced strength in proximal muscles (3/5 at shoulders and hips, 4/5 at elbows and knees, and 5/5 at wrists and ankles). She walked slowly and was unable to rise from a chair without using her arms; Test Name: Pulmonary function; Result Unstructured Data: Test Result:showed a mixed obstructive and; Comments: restrictive pattern with normal diffusion capacity for carbon monoxide.; Test Name: lung imaging; Result Unstructured Data: Test Result:revealed subpleural reticulation; Comments: compatible with interstitial lung disease; Test Name: erythrocyte sedimentation rate; Result Unstructured Data: Test Result:39; Test Name: rheumatoid factor; Test Result: Positive ; Test Name: skin exam; Result Unstructured Data: Test Result:unremarkable; Test Name: MRI/magnetic resonance venogram of the abdomen; Result Unstructured Data: Test Result:showed compression of the left common iliac vein; Comments: consistent with a diagnosis of May-Thurner Syndrome; Test Name: vital signs; Result Unstructured Data: Test Result:normal; Test Name: blood cell counts; Result Unstructured Data: Test Result:normal