Case Of Paroxysmal Nocturnal Hemoglobinuria Research Articles

The Budd-Chiari Syndrome as a Complication of Paroxysmal Nocturnal Hemoglobinuria (Clinical Case)

Among the main causes of recurrent thrombosis in young patients there is paroxysmal nocturnal hemoglobinuria (PNH), a complication of which is Budd-Chiari syndrome (BCS), characterized by thrombosis of the hepatic veins and/or inferior vena cava. Detection of PNH is an extremely important task, because its untimely diagnosis leads to recurrent thrombosis, deterioration of the patient’s quality of life, and increased mortality from complications which accompany PNH. The article analyzes a clinical case of PNH in a young patient with recurrent BCS, which illustrates the relevance and timely diagnosis of this disease. As a result of unsuccessful pharmacological treatment and progression of liver insufficiency, the patient had liver transplantation. After surgery and standard post-transplantation therapy the patient’s condition improved, but after some time a recurrence of hepatic vein thrombosis was developed. After hematologist consultation and performing flow cytometry, the patient was diagnosed PNH. However, on the background of recurrent hepatic vein thrombosis, immunosuppressive therapy, and the lack of targeted treatment for PNH, multiple organ failure was developed, which led to the patient’s death. PNG is one of the orphan diseases, which is characterized by a severe, chronic, progressive course and accompanied by the formation of degenerative changes in the body, a decrease in the quality and shortening of the patient’s life. Targeted therapy can reduce the risk of thrombosis, red blood cell transfusions and improve the quality of life of patients with PNH.

Paroxysmal Nocturnal Hemoglobinuria and Primary Myelofibrosis as an Extremely Rare Combination of Clonal Hematological Diseases: A Literature Review and Two Clinical Case Reports

The combinations of paroxysmal nocturnal hemoglobinuria (PNH) and chronic myeloproliferative neoplasms (CMPNs) are extremely rare. All of them refer to clonal hematological diseases and are characterized by high thrombosis risk, which most commonly causes death. This paper provides literature data on 38 combined cases of PNH and Ph-negative/Ph-positive CMPNs mainly in the “case report” format, taken from 22 sources published in 1970–2022. Additionally, the paper reports personal experience with 2 combined cases of PNH and primary myelofibrosis (PMF/PNH) from the archive of the Moscow Municipal Center for Hematology (SP Botkin City Clinical Hospital).

A Case of PNH with Abdominal Pain, AKI and Hemolytic Anemia

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare hematopoietic stem cell disorder affecting 1 to 10 people per million. With an associated 10-year mortality, PNH is a life-threatening disorder where the complement system of the body's innate immune system prematurely lyses red blood cells. It can be characterized by a number of clinical features, the most common being hemolytic anemia, pancytopenia, and thrombosis. 45 year old African American male presented with a chief complaint of shortness of breath x 2-3 days. Reports associated dry, nonproductive cough, congestion, myalgias onset one week prior. He was taking two tablets of Advil daily since symptom onset. He has a past medical history of right sided BKA after motor vehicle accident and currently uses a prosthetic leg. No other significant past medical history noted. On ED admission, the patient was febrile to 103.2F, tachycardic to 110 beats per minute, tachypneic to 26 breaths per minute, and normotensive to 128/64. On physical exam, there was conjunctival pallor, no scleral icterus, and right BKA. The remainder of the physical exam was unremarkable. Labs on admission were notable for anemia (Hgb 3.9, baseline of 9.2, 2 years prior), AKI (Cr 7.3, baseline of 0.9), elevated LDH 2336, and low Haptoglobin <10. Platelet count WNL throughout admission however there was a drop from 242 to 180 between Day 1 and 2 of admission. Peripheral smear did not show schistocytes however ADAMTS13 sent per heme/onc consult. Anemia improved to Hgb 7.6 on Day 3 of admission status post 4 units packed red blood cell transfusion. Workup for hemolytic anemia with AKI was pursued: Direct Coombs test negative, PNH screen sent. SPEP and UPEP unremarkable. On Day 6 of admission, flow cytometry showed evidence of PNH clone upon analysis of RBCs, granulocytes, and monocytes. AKI was attributed to ATN s/t heme-pigment deposition vs NSAID use and Cr trended down to 2.9 prior to discharge. On day 7 of admission, patient developed severe abdominal pain, not associated with fevers, chills, nausea, vomiting, or diarrhea. Pain moderately improved with Norco, ultrasound imaging was negative, and unable to CTA given renal function. Pt was started empirically on therapeutic anticoagulation with Lovenox, as the literature reports a high incidence of venous and/or arterial thrombosis in PNH w/granulocyte count >50% (89.8% in this patient). Patient was discharged the next day with close outpatient hematology follow-up with plan to start eculizumab. Given patient's presentation of fever, symptomatic anemia, and AKI the differential diagnosis included: hemoglobinopathies, red cell membrane disorders, PNH, DIC, TTP, HUS, AIHA, and infections such as malaria or HIV. It was difficult to identify PNH as the cause in this patient on ED presentation as there was no reported urine discoloration. Though classified as an acquired disorder through mutation of a gene on the X chromosome, it occurs in equal distribution among men and women. PNH specifically occurs through the mutation of a gene involved in the synthesis of glycosylphosphatidylinositol (GPI), an anchor protein for complement regulatory proteins that prevent complement-induced hemolysis of red blood cells. The resulting GPI deficiency leads to the unregulated formation of complement attack complexes that damage the cell membrane causing them to lyse. This intravascular hemolysis is seen as decreased levels of Hgb and hemoglobinuria that leads to elevated levels of LDH as seen with this patient. The degree of hemolysis and PNH clone size can increase risk of thrombosis, the leading cause of death in patients with PNH. Strong indicators for the start of PNH therapy are severe anemia, thrombosis, renal dysfunction, and dyspnea. The typical management of PNH in patients with thrombosis is shown in this case as the patient is put on therapeutic anticoagulation and plans for eculizumab, a monoclonal antibody that is a complement inhibitor used to prevent hemolysis. This PNH therapy will likely be administered lifelong and decrease the need for RBC transfusions as well as decrease thromboembolic rate. If the patient is unresponsive to eculizumab they become a strong candidate for allogeneic stem transplantation. This patient meets the popular standard for starting primary prophylaxis for management of thrombosis with a PNH clone size >50%.

Clinico-Molecular Risk Factors and Management of Thrombosis in a Large Real-Life Cohort of Patients with Paroxysmal Nocturnal Hemoglobinuria in the New Era of Anti-Complement Inhibitors and Doacs

The increased propensity for thrombotic events (TE) is well established in patients with paroxysmal nocturnal hemoglobinuria (PNH) and represents the main cause of disease morbidity/mortality. While the precise pathogenesis of TE remains ill-defined and likely multifactorial, cases with fully blown hemolytic PNH clones show the highest risk for such complications, often occurring in atypical localizations including the hepatic circulation (e.g., Budd-Chiari syndrome, BCS). The introduction of anti-complement therapy greatly abated hemolysis and thrombosis, demonstrating the crucial involvement of the underlying hemolytic process in triggering TE. Despite the current availability of PNH-directed treatment, a scarcity of data exist on anticoagulation and specifically on the efficacy of direct oral anticoagulants (DOACs) in this setting. Here, we took advantage of a large, real-life cohort of patients with classical hemolytic PNH to unravel determinants of thrombosis and decipher anticoagulation strategies in cases developing TE. Among 106 PNH cases (M:F ratio 0.86, median age 39 years, IQR 26-58) followed-up for a median of 68 months (95% CI 50-92), 42% were primary and 58% had antecedent aplastic anemia. Median granulocyte clone size at diagnosis was 71% (46-90) with the majority of cases classified as type III dominant red blood cells (RBCs) clone (81%) by flow cytometric analysis.1In total, 77% of cases harbored PIGA mutations by multi-amplicon deep NGS at a median ploidy-adjusted VAF of 20% (9-33), of whom 58% presenting multiple hits (clonal mosaicism).1 A total of 33 patients (31%) experienced TE, of which 84% occurred as the initial disease manifestation prompting to seek medical attention, 13% during a temporary discontinuation of anti-complement treatment (e.g., preparation to allogeneic bone marrow transplant), and only 3% (N=1) during treatment. Overall, the majority of patients had TE originating in the venous system (91%), arterial cerebrovascular district (6%) or both (3%). TE occurred typically in unusual sites with BCS as the most frequent (34%) followed by deep vein thrombosis (DVT, 20%), DVT complicated by pulmonary embolism (14%), splanchnic (14%), cerebral sinuses and superficial veins (9% each). No differences in disease ontogenesis (primary vs secondary to AA), and baseline variables such as age, PNH clone size, gender, PIGA mutations (presence, type and clonal burden), blood counts, reticulocytes, LDH, creatinine and transaminases were observed. Interestingly, patients experiencing TE were more commonly presenting with type II RBC phenotype (36% vs 13%; p=.027), had median lower albumin (4 vs 4.5 g/dL; p<.001) and elevated D-dimers (1520 vs 325 ng/mL; p=.003) as compared to non-TE cases. Patients with superficial TE were promptly started on anti-complement treatment, while the others improved with additional anticoagulation. One patient with portal vein thrombosis had severe thrombocytopenia and eventually died due to progressive BCS. Anticoagulation strategy consisted of warfarin (50%), DOACs (29%) and low molecular weight heparin (LMWH, 21%) with a median treatment duration of 44 months (17-73). LMWH was preferred in patients with thrombocytopenia (median platelets 45 vs 102x109/L in cases receiving other therapeutics; p=.03). In 1 patient, warfarin was switched to DOACs for prolonged treatment, 2 BCS cases underwent TIPS, and in 1 case with DVT an inferior vena cava filter was positioned because of the concomitant diagnosis of myeloproliferative neoplasm with MPLW515L. Recurrence of TE under anticoagulants was noted in only 2 cases receiving warfarin, whereas 7 (N=5 warfarin/ 2 DOACs) experienced bleeding. Two patients on DOACs had acute rectal hemorrhage with additional bleeding risk factors (clopidogel, ulcerative colitis). No thrombotic recurrence was observed in all 9 patients treated with DOACs at a median observation time of 24 months (12-95). While previously TE prompted lifelong anticoagulation, the control of the underlying disease with anti-complement drugs enabled its successful discontinuation in 42% of patients without any TE recurrence at a median time of 50 months (15-90). This is the largest hemolytic PNH series ever reported detailing clinico-molecular risk factors, characteristics of TE and their management in the era of anti-complement therapy and DOACs, whose use in such a setting warrants attention and further studies.

Difficulties in diagnosing paroxysmal nocturnal hemoglobinuria in a municipal internal disease hospital

Background: The purpose of this work is to present a case of paroxysmal nocturnal hemoglobinuria in the clinical practice of an internist for the purpose of differential diagnosis with other diseases with the jaundice syndrome in a city hospital.&#x0D; Clinical case description: Patient H., 51-year-old, was seen at the emergency department of the city hospital due to the periodic appearance of jaundice with dark-colored urine and fever. The physical and laboratory examination methods revealed an enlargement of the spleen, signs of mild hemolytic anemia, severe thrombocytopenia, a significant increase in the markers of cytolysis and cholestasis. Proteinuria and cylindruria were noted in the urine analysis. In terms of a differential diagnosis, Gilberts syndrome, viral hepatitis, hemorrhagic fever were considered.&#x0D; Conclusion: Based on the data obtained, hemolytic and uremic syndromes were suspected. A therapy with iron preparations, vitamin B12, infusions of glucose and saline was applied with the positive clinical and laboratory dynamics. GPI-linked glycoproteins were determined on the surface of red blood cells (CD59), neutrophils (CD 24/FLAER), and monocytes by FLAER-/CD14 flow cytometry, which confirmed the diagnosis of paroxysmal nocturnal hemoglobinuria.

Popliteal artery thrombosis as a rare complication of paroxysmal nocturnal hemoglobinuria (PNH): A case report.

Introduction and importancePopliteal artery thrombosis a rare but life-threatening complication of Paroxysmal Nocturnal Hemoglobinuria caused due to hemolysis. Complications of further thrombotic event are common after initial management.Case presentationA 38 years old male, known case of PNH for 2 years, presented with the history of loss of pain sensation, coldness and loss of movement in left lower leg for 5 days and history of multiple blood transfusion. The patient underwent knee amputation because of possible complication of PNH.Clinical discussionIntermittent claudication along with paresthesia, lower extremity weakness, stiffness, and cool extremities are seen in patients of Peripheral Artery Disease. Ultrasound color duplex is a sensitive and specific examination for peripheral flow while gold standard techniques like MRI and CT angiogram to detect and diagnose arterial lesions.ConclusionThe risk of thrombo-embolism in a patient of PNH should be considered by a treating doctor while early imaging and management should be done to reduce the complications and risk of amputation.

Centennial development of paroxysmal nocturnal hemoglobinuria research in Peking Union Medical College Hospital

<p indent=0mm>Paroxysmal nocturnal hemoglobinuria (PNH) is a rare acquired clonal hematopoietic stem cell (HSC) disease. A somatic phosphatidylinositol glycan-A (PIGA) gene mutation in HSCs translates into abnormal biosynthesis of glycosyl phosphatidylinositol (GPI) anchors on the cell surface. The absence of GPI-anchored complements regulators leads to complement-driven blood cell lysis. Hemolysis and chronic anemia are the most common clinical manifestations, while bone marrow failure is a rare but life-threatening complication. Thrombosis is the leading cause of mortality. Transfusion and supportive care have been introduced as symptomatic treatments since the early decades of the last century. Eculizumab, a monoclonal antibody that blocks terminal complement at C5, is a breakthrough medicine that changed the standard treatment methods of PNH. However, in cases where eculizumab is not accessible, allogeneic HSC transplantation could be an alternative strategy for refractory and aplastic patients. The Peking Union Medical College Hospital (PUMCH) is approaching its centennial anniversary in 2021. The first case of PNH in China was reported by physicians at PUMCH in the 1950s. During the past century, generations of hematologists established the largest cohort of PNH patients in China while continuously developing novel laboratory tests for this disease. They collaborated with investigators of basic science on the pathogenetic mechanisms of bone marrow failure and thrombosis. Although great historical changes have impacted academic progress, the spirit of perseverance, commitment, and innovation in older generations is passed on to the next generations. In this paper, we summarize the clinical evolution of PNH treatment along with basic science at PUMCH, which in turn facilitates great progress in PNH in the era of the 21st century in China.

Clinical characteristics and therapeutic outcomes of paroxysmal nocturnal hemoglobinuria patients in Turkey: a multicenter experience.

The aim of this study is to collect paroxysmal nocturnal hemoglobinuria (PNH) patient data from hematology centers all over Turkey in order to identify clinical features and management of PNH patients. Patients with PNH were evaluated by a retrospective review of medical records from 19 different institutions around Turkey. Patient demographics, medical history, laboratory findings, and PNH-specific information, including symptoms at the diagnosis, complications, erythrocyte, and granulocyte clone size, treatment, and causes of death were recorded. Sixty patients (28 males, 32 females) were identified. The median age was 33 (range; 17-77) years. Forty-six patients were diagnosed as classic PNH and 14 as secondary PNH. Fatigue and abdominal pain were the most frequent presenting symptoms. After eculizumab became available in Turkey, most of the patients (n = 31/46, 67.4%) were switched to eculizumab. Three patients with classic PNH underwent stem cell transplantation. The median survival time was 42 (range; 7-183months) months. This study is the first and most comprehensive review of PNH cases in Turkey. It provided us useful information to find out the differences between our patients and literature, which may help us understand the disease.

Difficult Cases of Paroxysmal Nocturnal Hemoglobinuria: Diagnosis and Therapeutic Novelties.

Paroxysmal nocturnal hemoglobinuria (PNH) is an intriguing disease that can pose many difficulties to physicians, as well as to hematologists, who are unfamiliar with it. Research regarding its pathophysiologic, diagnostic, and therapeutic aspects is still ongoing. In the last ten years, new flow cytometry techniques with high sensitivity enabled us to detect PNH clones as small as <1% of a patient’s hematopoiesis, resulting in increasing incidence but more difficult data interpretation. Particularly, the clinical significance of small PNH clones in patients with bone marrow failures, including aplastic anemia and myelodysplastic syndromes, as well as in uncommon associations, such as myeloproliferative disorders, is still largely unknown. Besides current treatment with the anti-C5 eculizumab, which reduced PNH-related morbidity and mortality, new complement inhibitors will likely fulfill unmet clinical needs in terms of patients’ quality of life and better response rates (i.e., responses in subjects with C5 polymorphisms; reduction of extravascular hemolysis and breakthrough hemolysis episodes). Still, unanswered questions remain for these agents regarding their use in mono- or combination therapy, when to treat, and which drug is the best for which patient. Lastly, long-term safety needs to be assessed in real-life studies. In this review, we describe some clinical vignettes illustrating practical aspects of PNH diagnosis and management; moreover, we discuss recent advances in PNH diagnostic and therapeutic approaches.

Utility of FLAER and CD157 in a five-color single-tube high sensitivity assay, for diagnosis of Paroxysmal Nocturnal Hemoglobinuria (PNH)-A standalone flow cytometry laboratory experience.

FLAER-based flow cytometry assay is considered the gold standard for diagnosis of paroxysmal nocturnal hemoglobinuria (PNH). CD157 is a recently reported marker for GPI-anchored protein found both on neutrophils and monocytes. This study highlights the robustness of FLAER and CD157 combination to identify PNH clones in a high sensitivity assay. Though rare, the data shown highlight the presence of CD157 negativity in few cases re-emphasizing the importance of FLAER for PNH diagnosis. A single 5-color tube-FLAER Alexa488/ CD157PE/ CD15PECy5/ CD64PE-Cy7 & CD45APCH7-was used for a high sensitivity PNH assay. Of 364 cases, 59(16.2%) cases had PNH clone in both granulocytes and monocytes. PNH clone sizes ranged from 0.02% to 96.6% in granulocytes and 0.07% to 96.3% in monocytes based on their FLAER-negative, CD157-negative phenotype. Twenty-two of the 59 PNH cases (37.3%) had WBC clone size of <1%. In addition, there were 10 cases which showed absence of CD 157 expression on both granulocytes and monocytes but on FLAER staining showed normal staining patterns. Three of these ten cases also showed a PNH clone based on absence of FLAER expression on both granulocytes and monocytes. FLAER and CD157 is a robust combination for diagnosis of clinical and subclinical PNH. Absence of CD157 expression in normal WBCs, though rare, should be kept in mind and re-emphasizes the importance of FLAER for the high sensitivity PNH assay.

Acute kidney injury with dark urine: the case of paroxysmal nocturnal hemoglobinuria

In this case report; we describe a patient with severe attack of paroxysmal nocturnal hemoglobinuria (PNH) following Ciprofloxacin therapy. He presented with recurrent abdominal pain, repeated vomiting and dark urine. Physical examination revealed severe pallor and jaundice. Laboratory investigations showed severe intravascular hemolysis with negative Coomb’s test, progressive acute kidney injury (AKI), sterile blood cultures and negative serology for autoimmune diseases. Subsequently, he developed pancytopenia. Ham test was positive and flow cytometry, later on, confirmed PNH. He was supported with multiple transfusions of packed blood cells and hemodialysis. Ciprofloxacin was discontinued and his PNH was treated with Solumedrol 1 g daily for 3 days followed by Prednisone 60 mg/day for 2 months. Two weeks later; his hemolysis abated and his AKI improved. Up to 5 years later, he still has minor PNH clone yet without disease activity. In conclusion; our patient had acute drug-induced hemolytic crisis associated with minor PNH clone. With drug-vigilance; no further relapses were reported and his PNH clone remained stable for 5 years. The case expands the spectrum of PNH phenotypes and its triggering factors.&#x0D; Keywords: AKI, anemia, autoimmune, flow cytometry, hemolysis, PNH.

FLAER‐negative CD15+ neutrophils can be used for the simplified screening of suspected PNH cases

The flow cytometry analysis of GPI-linked proteins on red blood cells and leukocytes is crucial for paroxysmal nocturnal hemoglobinuria (PNH) diagnostics. However, the commonly used multicolor panels cannot be implemented in low-resourced hematology laboratories. In order to develop a simple prediagnostic test for PNH screening, we analyzed the diagnostic accuracy of the two-color (FLAER/CD15) detection of GPI-deficient neutrophils. We reanalyzed multicolor data set of 1594 peripheral blood samples of patients screened for PNH applying only two markers (FLAER/CD15). The quantitative positivity/negativity was reported. Then, these results were compared in a blinded manner with previously obtained multicolor data from the same samples. Among the 1594 samples included in the study, 507 samples were PNH-positive by the multicolor assay. The two-color method revealed 510 PNH-positive samples. The detailed examination of this discrepancy revealed 12 false-positives and 9 false-negatives. Therefore, FLAER/CD15 screening method displayed 98.90% of the diagnostic specificity and 98.22% of the sensitivity. This simple two-color evaluation of FLAER-negative neutrophils is a highly effective screening test for PNH. Although this approach is not intended to replace the multicolor diagnostic procedure, it could minimize the number of patients requiring a conventional multicolor flow cytometric assay.

Epidemiology of PNH and Real-World Treatment Patterns Following an Incident PNH Diagnosis in the US

Introduction: Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired, life-threatening blood disease. While PNH is known to be a rare disease, the incidence and prevalence of the condition has been described only in a few small studies. In addition, while the International PNH registry is a rich source of data on real-world PNH patients globally, it is not possible to estimate the incidence and prevalence of PNH directly from the registry. As complement inhibitors are becoming the standard of care for PNH treatment, we also sought to explore how patients are managed following an incident PNH diagnosis. The objective of this study was to estimate the incidence and prevalence of PNH and to describe real-world treatment patterns among patients newly diagnosed with PNH in the United States (US). Methods: We conducted a retrospective cohort study using Truven US MarketScan Commercial/Medicare data (1 Jan 2015 to 30 June 2018), an employer-sponsored insurance claims database including annually approximately 30 million insured patients and their dependents' complete longitudinal records of inpatient services, outpatient services, and prescription drug claims covered under a variety of fee-for-service and capitated health plans. While these data are considered nationally representative of Americans with employer-provided health insurance, data come mainly from large employers. To estimate prevalence, we identified patients with ≥ 1 PNH diagnosis (ICD10: D59.5) among persons continually enrolled in the databases in 2017. To estimate incidence, we required ≥1-year of baseline enrolment and no PNH diagnosis or eculizumab exposure, identified using national drug codes [NDC] or procedure codes for drug administration, during the baseline period. Person-time accrued post-baseline until PNH diagnosis, end of study period, or disenrollment. We stratified incidence and prevalence estimates by age and sex and described patients with incident PNH in terms of demographics, comorbidities, and past-year healthcare resource utilization. Using Kaplan-Meier estimators, we estimated incidence of eculizumab initiation, timing of initiation, treatment duration, and risk of discontinuation/treatment holiday (&amp;gt;42 days between eculizumab exposures [i.e. 14-day exposure period + 28-day grace period between infusions], the equivalent of missing 2 infusions assuming a bi-weekly infusion schedule for eculizumab) following the incident PNH diagnosis. While accounting for censoring, we also investigated patterns of red blood cell (RBC) transfusions, identified using procedure codes, in terms of incidence and timing of first transfusion following an incident PNH diagnosis. Results: The prevalence of PNH varied little between 2016 and 2017, from 12 to 13 per 1,000,000. The incidence rate over the study period was 5.7 per 1,000,000 person-years, representing 257 incident PNH cases. The incidence rate of PNH increased with age and was similar across sex. At diagnosis, mean age was 50.0 years (standard deviation [SD]: 18.6), 3.1% (8/257) were less than 18 years, 52.1% were women, 19.5% had a past-year diagnosis of aplastic anemia, 8.2% had a past-year diagnosis of myelodysplastic syndrome, 14.0% had a past-year RBC transfusion, and 31.5% had been hospitalized in the past-year. Over a mean follow-up time of 385.6 days (SD: 253.2), 10.3% (95% confidence interval [CI]: 6.3-14.1%) of patients initiated eculizumab on average 60.5 days (SD: 55.9) from PNH diagnosis. At 1 year, about one third of patients discontinued eculizumab or had taken a treatment holiday; average treatment duration was 328.2 days (SD:245.4). Cumulative incidence of RBC transfusions at 6 months and 1 year was 14.6% (10.1-18.9%) and 17.4% (12.2-22.3%), respectively. On average, the first RBC transfusion occurred within 63.6 days (SD: 114.4) of an incident PNH diagnosis. Conclusions: In routine clinical practice, only a minority of patients recently diagnosed with PNH are initiated on eculizumab. Among PNH patients treated with eculizumab, less than 70% remain on treatment after 1 year. Findings must be interpreted in the context of limitations including lack of information on clone size, symptom burden, measures of disease activity, or bone marrow failure state which may affect treatment course. Future studies should explore factors affecting eculizumab initiation and persistence on treatment. Disclosures Jalbert: Regeneron Pharmaceuticals, Inc.: Employment, Equity Ownership. Chaudhari:Regeneron Pharmaceuticals, Inc.: Employment, Equity Ownership. Zhang:Regeneron Pharmaceuticals, Inc.: Employment, Equity Ownership. Weyne:Regeneron Pharmaceuticals, Inc.: Employment, Equity Ownership. Shammo:Incyte: Consultancy, Honoraria, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; Alexion: Consultancy, Honoraria, Research Funding, Speakers Bureau; Onconova: Research Funding; Apellis: Membership on an entity's Board of Directors or advisory committees; Sanofi: Consultancy, Honoraria, Speakers Bureau; Astex Pharma: Research Funding; Novartis: Consultancy, Honoraria; Otsuka: Consultancy, Honoraria; CTI Pharma: Research Funding.

Retrospect Reviews of PNH Tests with Long-Term Follow-up in a Single Institution

I ntroduction : Paroxysmal nocturnal hemoglobinuria (PNH) often presents as hemolysis and/or bone marrow failure. Flow cytometric testing can accurately detect PNH. However, the long term studies on PNH clone size and how it relates to clinical course are few. We sought to understand how PNH clone size correlates with clinical course over time and the impacts on clone size with different treatments. Here we report long term clone size monitoring and clinical data of 57 patients with PNH in a single intuition. Methods : High sensitivity PNH flow cytometry (0.01% limit of detection) was performed with FLAER-FITC, CD64-PE, CD14-ECD, CD15-PC5, CD24-AA7500, CD45-KO for neutrophils &amp; monocytes; CD59-PE and CD235a-AA750 for RBCs. Retrospective analysis was done in the positive PNH cases from 2008-2019 at OHSU. Total 173 cases for 57 patients; including 27 females and 30 males, 52 adults and 5 pediatrics, with a mean age of 45 (range 9-78). We also reviewed results of serum LDH, bone marrow biopsies and molecular/cytogenetics of these patients. Among of these patients, 18 patients (11 females and 7 males, mean age 49.33, age range 29-73) with long term (at least over 4 years) follow-up have more than 3 PNH tests. Besides PNH clone on RBC and PMN, we also reviewed results of WBC count (x103/ul), Hb (g/dL), PLT (x103/ul) serum LDH (U/L), bone marrow biopsy reports and molecular/cytogenetics findings in these patients. Results: Among 57 patients, there are 30 aplastic anemia (AA) patients (53.63%), 7 AA patients progressing to PNH (AA&amp;PNH, 12.28%), 5 myelodysplastic syndromes (MDS, 8.77%), 12 PNH patients (21.05%), 1 pancytopenia, 1 autoimmune disease, 1 thrombosis. The diagnosis of AA and MDS were confirmed by bone marrow biopsy and molecular/cytogenetics. Significantly higher levels of all PNH clones were observed in PNH and AA/ PNH, compared to AA (all P &amp;lt;0.001) and MDS (all P&amp;lt;0.05) shown in Figure A-D. LDH was higher in PNH and AA/PNH than AA and MDS groups (P&amp;lt;0.001, Figure E). LDH demonstrated positive correlation with PNH clone size in RBC-type-III, neutrophils and monocytes (all P&amp;lt;0.0001, R= 0.4447, 0.5469, 0.5711, respectively, Figure F). No correlation was observed between LDH and RBC-type-II. Long term (4-11 years ) follow up include 18 patients were divided into 4 groups: 5 AA treated with immunosuppressant only, 5 AA treated with immunosuppressants and/or eltrombopag, 5 classic PNH or AA that progressed to PNH treated with immunosuppressants and/or eculizumab, and 3 PNH with observation and supplements only. The study showed immunosuppression only has lowest PNH clone size for both RBC and WBC (Figure G-H). As for the Hb and WBC count, there were no statistics differences among 4 groups (Figure I-J). Decreased PLT was detected in eltrombopag group (Figure K). Significantly, increased LDH was observed in the observation/supplement group (Figure L). Interestingly, all these 3 patients without special treatment have high PNH clones and LDH from diagnosis to now over 10 years. Despite receiving basic supportive care, the patients' clinical courses have been stable with only supplementation of vitamin B12 and Folic Acid. Conclusions : Positive PNH test was most frequently seen in AA patients. AA has lower PNH clone size and LDH than those of PNH patients or AA progressed to PNH patients. For all patients, PNH population showed positive correlation with LDH. Our study suggest that it is necessary to follow PNH clone size, as this may impact the decision of when to start therapy with what agents. Figure Disclosures No relevant conflicts of interest to declare.

FLAER Based Assay According to Newer Guidelines Increases Sensitivity of PNH Clone Detection.

Flow cytometry has become 'gold standard' for detecting abnormal clones in paroxysmal nocturnal hemoglobinuria (PNH), aplastic anemia (AA) and myelodysplastic syndrome (MDS). This pilot study was conducted in 2015 with a primary aim to evaluate the utility of single tube fluorescent aerolysin (FLAER) based testing and its comparison with two tubes non-FLAER based testing (CD55, CD59, CD24 and CD66b) in detecting abnormal PNH clones in these newly diagnosed cases. The secondary aim was an attempt to distinguish PNH from AA/MDS cases associated with PNH clones based on clinical, laboratory features and clone size at diagnosis. In this study, the abnormal PNH clones were detected using a single tube FLAER based testing and two tubes non-FLAER based testing in all cases of PNH (n = 12), healthy subjects (n = 18) and AA/MDS with PNH clone (n = 9) and compared with clinical and laboratory features at diagnosis. The receiver operator curve (ROC) analysis defined the optimal cut-offs for FLAER in granulocytes (> 0.7%) and monocytes (> 0.9%). There was significant positive correlation between FLAER and non-FLAER based testing in these cells (r > 0.3 and p < 0.05). FLAER based testing helped us in picking up smaller clones which were missed by latter technique in four patients thereby increasing its sensitivity and also technically proved to be cost-effective (Rs. 1800 vs. Rs. 2100). Even in PNH patients, the clone size was slightly higher by using FLAER when compared to non-FLAER based antibodies panel. The clone size of monocytes was always higher than granulocytes in both PNH and AA/MDS groups. Bone marrow cellularity and mean size of granulocytes and monocytes clone at diagnosis showed a striking statistically significant 'p' value of < 0.0001 between these groups. In this pilot study, a single tube FLAER based PNH testing had improved clone detection in all cases of PNH, AA/MDS with PNH clones. The clone size was > 30% in majority of PNH cases whereas in AA/MDS, it was usually < 10% at diagnosis. Hence this newer technique not only increased the sensitivity of PNH clone detection but also proved to be cost-effective.

Analysis of clinical characteristics of 92 patients with paroxysmal nocturnal hemoglobinuria: A single institution experience in China.

ObjectivesWe performed a retrospective analysis to investigate the clinical characteristics and therapeutic strategies of Chinese paroxysmal nocturnal hemoglobinuria (PNH) patients, and assessed the efficacy and safety of glucocorticoid in PNH patients.MethodsThe clinical data of 92 PNH cases in our hospital were analyzed, including clinical manifestation, laboratory examination, treatment efficacy, and survival.ResultsThe main clinical manifestations of these patients included hemoglobinuria, anemia, fatigue, dyspnea, headache, abdominal pain, and erectile dysfunction. Glucocorticoid is still the first‐line treatment for PNH patients to control hemolytic attack, and the short‐term remission rate (12 months) is 79.01% (64/81). Meanwhile, the overall survival (OS) of 10 years after diagnosis was estimated as 70.77% (46/65). Moreover, Cox proportional risk model for multivariate analysis showed that the increase in LDH multiple, thrombosis complications, and complicated with bone marrow failure were the independent adverse prognostic factors affecting the survival of PNH patients.ConclusionParoxysmal nocturnal hemoglobinuria patients in mainland China have various clinical features, while lower incidences of thrombosis and renal damage. Thrombosis and bone marrow failure are two complications with worse prognosis.

A Case of Paroxysmal Nocturnal Hemoglobinuria with Renal Hemosiderosis

Paroxysmal nocturnal hemoglobinuria (PNH) is a clonal disorder of bone marrow. It is characterized by blood cells lacking membrane proteins that are normally attached by the glycosylphosphatidylinositol anchor. It usually presents with intravascular hemolysis, cytopenias, frequent infections, bone marrow hypoplasia, and a high incidence of life-threatening venous thrombosis. Kidney involvement is usually benign and secondary to chronic tubular deposition of hemosiderin. Acute kidney injury may occur in association with a hemolytic crisis. Here, we report a case of a 50-year-old male with hematuria, pancytopenia, and acute renal failure due to PNH. Renal biopsy demonstrated acute tubular necrosis with considerable hemosiderin deposition (hemosiderosis), but no evidence of vascular thrombosis.

A Case of Paroxysmal Nocturnal Hemoglobinuria (PNH) in an Obstetric Patient: A South African Perspective

Paroxysmal Nocturnal Hemoglobinuria (PNH) originates from an acquired genetic defect in a multipotent hematopoietic stem cell that becomes stem-cell-like in its ability to survive, expand, and self-renew. PNH is a rare condition characterized by intravascular hemolysis. PNH can arise anew or in the setting of an underlying bone marrow disorder such as aplastic anemia (AA), myelodysplastic syndrome (MDS), or primary myelofibrosis (PMF).This case presentation documents the challenging diagnosis of PNH in the obstetric setting, in which other possible causes for a hemolytic anemia could be considered. We discuss the management of a pregnancy in the presence of PNH in a low-to-middle income setting.

Efficacy and safety of Eculizumab in Paroxysmal Nocturnal Hemoglobinuria (PNH) after 15 years steroids treatment: a case report description.

Background Paroxysmal Nocturnal Hemoglobinuria (PNH) pathogenesis is due to acquired lack of glycosylphosphatidylinositol-anchored protein complement regulatory proteins (CD55 and CD59) and intra-extravascular hemolysis. Eculizumab is a monoclonal antibody binding complement protein 5 (C5 receptor CD59), blocking complement upstream and reducing hemolysis. Case Summary In 1999 we diagnosed PNH in a male 54 year-old. Therapy with prednisone and blood transfusions started. After 13 years (2012) of continuative steroid, we started eculizumab every 14 days. Clinical and laboratory improvement has been reported, the prednisone therapy has been tapered; no further hemolytic crises reappeared. However, mild anemia, high reticulocytes count, high LDH serum levels are still reported. Actually, despite to suboptimal response, the patient shows a good quality of life. Conclusion Here we report a case of PNH with a fully documented medical history of long-term steroid therapy confirming efficacy and safety of eculizumab. However “C3 tick over” effect may induce suboptimal clinical results with residual hemolytic activity also on heavy steroid treated patients.

The Value of Population Based Data to Study Rare Diseases: An Example Using the Department of Defense Healthcare System

The Value of Population Based Data to Study Rare Diseases: An Example Using the Department of Defense Healthcare System