免疫性血小板減少症

BACKGROUND: Helicobacter pylori (H. pylori) is well known as an etiological agent in several gastric diseases, including chronic gastritis, gastric and duodenal ulcers, gastric carcinoma, and lymphoma. Over the past decades, the understanding of its pathogenic role has evolved substantially, overcoming initial skepticism and establishing the bacterium as a major factor in gastroduodenal disease. However, epidemiological and experimental studies suggest that this chronic infection may also be associated with a variety of extragastric conditions. OBJECTIVE: This review aims to evaluate the relationship between H. pylori infection and anemia, immune thrombocytopenic purpura, colorectal cancer, cardiovascular diseases, and neurological disorders. METHODS: For each association, the most recent evidence and current recommendations regarding the diagnosis and treatment of H. pylori infection during the clinical course of these conditions were assessed. CONCLUSION: Further prospective studies are needed to clarify whether these associations represent causal relationships with clinical relevance or merely statistical correlations, and to better determine the impact of H. pylori infection on extragastric diseases.

Herein, we describe a 22-month-old girl who presented with isolated severe thrombocytopenia (nadir platelet count: 6 × 10⁹/L) without overt microangiopathic hemolysis. The patient exhibited a partial clinical response to both corticosteroids and intravenous immunoglobulin (IVIG). Bone marrow examination showed increased megakaryocytes, with platelet-producing megakaryocytes accounting for 15% of the total megakaryocyte population. Initial whole-exome sequencing (WES) yielded negative findings for definitive pathogenic variants and clinically significant copy number variations (CNVs). Subsequent targeted genetic testing identified compound heterozygous ADAMTS13 variants: a paternally derived heterozygous exon 8 deletion validated by quantitative PCR (qPCR), and a maternally derived heterozygous frameshift mutation c.2764_2767dup (p.Ala923ValfsTer66) in exon 22 confirmed by Sanger sequencing. Functional analysis revealed severely diminished ADAMTS13 activity (0.23%) with undetectable inhibitory antibodies. The patient's family history was remarkable for a first-trimester miscarriage and a previous neonatal death attributed to severe thrombocytopenia complicated by pulmonary hemorrhage. This case highlights two critical diagnostic pitfalls of pediatric hTTP: atypical presentation with isolated thrombocytopenia and misleading partial responsiveness to immunosuppressive therapy. In addition, routine WES has inherent limitations in detecting exon-level CNVs and certain frameshift variants. For children with unexplained recurrent thrombocytopenia and a suggestive familial bleeding history, ADAMTS13 functional assessment and targeted genetic sequencing should be performed promptly, even if initial WES results are unremarkable.

Coronary artery anomalies (CAAs) are rare congenital variations with a broad spectrum of clinical implications. While certain configurations are associated with myocardial ischemia and sudden cardiac death (SCD), many remain clinically silent and are discovered incidentally. An anomalous origin of the left main coronary artery (LMCA) from the right coronary artery (RCA) represents an exceptionally uncommon variant, particularly when it arises from the proximal RCA and follows a prepulmonic course. We report the case of a 56-year-old female with a history of immune thrombocytopenic purpura who presented with atypical chest discomfort. She underwent coronary computed tomography angiography (CCTA), which revealed an LMCA originating from the proximal RCA with a prepulmonic (anterior) course, consistent with a Lipton right sinus of valsalva, type II, anterior (RIIA) single coronary artery (SCA) pattern. The coronary artery calcium score was zero, and no evidence of obstructive coronary artery disease was identified. Given the absence of ischemia and the benign anatomical course, the patient was managed conservatively. She underwent periodic outpatient surveillance with symptom reassessment and cardiovascular risk factor monitoring, remaining asymptomatic over three years without adverse cardiac events. Single coronary artery anomalies are rare, with reported prevalence estimates of approximately 0.06% in angiographic series, although these data may be influenced by referral bias. Among these, LMCA arising from the RCA accounts for only 0.0024%-0.02% of reported cases. Clinical significance depends on vessel course as well as associated morphological features. Interarterial variants carry higher risk, whereas prepulmonic and retroaortic courses are generally considered lower risk. CCTA is valuable for defining anatomy and guiding individualized risk stratification, while functional testing may be considered selectively when symptoms or uncertain hemodynamic significance are present. This case highlights a rare but benign coronary anomaly and underscores the importance of integrating anatomical findings, clinical presentation, and selective adjunctive testing to guide management while avoiding unnecessary invasive intervention.

RATIONALE: Systemic lupus erythematosus (SLE)-associated thrombotic microangiopathy with features of atypical hemolytic uremic syndrome (aHUS) is a rare but life-threatening complication. Early recognition is challenging because of its overlapping clinical manifestations with other thrombotic microangiopathies. PATIENT CONCERNS: A 49-year-old man with SLE presented with anemia, thrombocytopenia, and multi-system involvement. Despite initial immunosuppressive therapy, his hematologic parameters progressively deteriorated, with hemoglobin decreasing to 89 g/L and the platelet count to 54 × 109/L. DIAGNOSES: Laboratory investigations demonstrated elevated lactate dehydrogenase (501 U/L) and markedly increased soluble complement membrane attack complex (sC5b-9, >1790 ng/mL). ADAMTS13 activity was normal (75.41%), excluding thrombotic thrombocytopenic purpura. Based on the clinical and laboratory findings, the patient was diagnosed with SLE-associated aHUS. INTERVENTIONS: Following the diagnosis, the patient received eculizumab, a monoclonal antibody targeting complement component C5. OUTCOMES: Within 6 days of eculizumab treatment, hemoglobin increased to 102 g/L, and the platelet count recovered to 108 × 109/L, indicating a rapid hematologic response. LESSONS: This case highlights that aHUS can occur as a severe complication of SLE, even in male patients. Complement-mediated thrombotic microangiopathy may coexist with and be triggered by immune hemolysis in SLE. Early recognition and prompt complement inhibition with eculizumab can produce an ultra-rapid hematologic response and may be critical for improving patient outcomes.