Acute Kidney Injury Resulting From Hemoglobinuria After Pulsed-Field Ablation in Atrial Fibrillation: Is it Preventable?

BACKGROUND

High-voltage pulses can cause hemolysis.

OBJECTIVES

The authors evaluated the occurrence of hemoglobinuria after pulsed-field ablation (PFA) and its impact on renal function in patients with atrial fibrillation (AF).

METHODS

A consecutive series of patients with AF undergoing PFA were included in this analysis. The initial patients who did not receive postablation hydration immediately after the procedure were classified as group 1 (n = 28), and the rest of the study patients who received planned fluid infusion (0.9% sodium chloride ≥2 L) after the procedure were categorized as group 2 (n = 75).

RESULTS

Of the 28 patients in group 1, 21 (75%) experienced hemoglobinuria during the 24 hours after catheter ablation. The mean postablation serum creatinine (S-Cr) was significantly higher than the baseline value in those 21 patients (1.46 ± 0.28 mg/dL vs 0.86 ± 0.24 mg/dL, P < 0.001). Of those 21 patients, 4 (19%) had S-Cr. >2.5 mg/dL (mean: 2.95 ± 0.21 mg/dL). The mean number of PF applications was significantly higher in those 4 patients than in the other 17 patients experiencing hemoglobinuria (94.63 ± 3.20 vs 46.75 ± 9.10, P < 0.001). In group 2 patients, no significant changes in S-Cr were noted. The group 2 patients received significantly higher amounts of fluid infusion after catheter ablation than did those in group 1 (2,082.50 ± 258.08 mL vs 494.01 ± 71.65 mL, P < 0.001). In multivariable analysis, both hydration (R2 = 0.63, P < 0.01) and number of PFA applications (R2 = 0.33, P < 0.01) were independent predictors of postprocedure acute kidney injury.

CONCLUSIONS

On the basis of our findings, both the number of PFA applications and postablation hydration were independent predictors of renal insult that could be prevented using planned fluid infusion immediately after the procedure.

Blackwater Fever Treated with Steroids in Nonimmune Patient, Italy

Causes of blackwater fever, a complication of malaria treatment, are not completely clear, and immune mechanisms might be involved. Clinical management is not standardized. We describe an episode of blackwater fever in a nonimmune 12-year-old girl in Italy who was treated with steroids, resulting in a rapid clinical resolution.

Changes to blood parameters after postparturient hemoglobinuria in 11 Holstein-Friesian cows

This study reviewed a case series of 11 Holstein-Friesian (HF) cows with postpartum hemoglobinuria (PPH) from one dairy herd. The first clinical signs of PPH appeared in the animals during the second or third lactation, between 21 and 30 days after calving. The clinical signs, including depression, diminished appetite, a dark red to brown color in the urine, pale mucous membranes, and a decrease in milk yields were observed in these 11 animals. Three of the cows developed jaundice of the mucous membranes and five had dry, parched feces. PPH was confirmed on laboratory test results of blood and urine samples. Anemia, serum hypophosphatemia (Pi = 0.79 mmoL/L), and increased liver function analytes (total bilirubin, total protein, and urea concentrations) were observed in all animals. Animals were treated with intravenous phosphorus supplementations for the first 2 days after clinical signs were noted, and then oral supplementations were administered. After the clinical signs resolved and the treatments were discontinued, the animals still had mild anemia; however, the phosphorus concentration increased to 1.40 mmoL/L. Gamma-glutamyltransferase activity increased compared with activities measured before treatments and total bilirubin concentrations decreased slightly; however, the concentrations were still more than twice the upper limit of the normal RI. These animals were diagnosed with liver damage that had developed over the course of PPH, indicating the need for the further monitoring and treatment of cows during the postparturient period, even if clinical signs are no longer present.

Hemoglobinuria in the Early Poststem-Cell-Transplant Period: Risk Factors and Association with Outcomes

Background

Information on risk factors of hemoglobinuria after hematopoietic stem-cell transplant (HSCT) and its association with AKI, mortality, and engraftment is limited.

Methods

We conducted a retrospective cohort study on all consecutive adults that underwent HSCT from January 6, 1999, to November 6, 2017. The study included 6039 patients that underwent bone marrow transplantation (BMT), umbilical cord blood, and peripheral blood stem-cell transplantation (PBSCT).

Results

Early post-HSCT, AKI occurred in 393 (7%) patients, and 52 (0.9%) patients had post-HSCT hemoglobinuria. Post-HSCT hemoglobinuria was associated with graft type (BMT+Cord), underlying disease (lymphoma, acute leukemia), and fludarabine-based conditioning regimen. Post-HSCT hemoglobinuria was associated with early (48-72 hours) post-HSCT AKI. Graft type (BMT+Cord) was associated with AKI among patients with hemoglobinuria. AKI in patients with hemoglobinuria was associated with delayed platelet engraftment and delayed WBC engraftment but not 100-day mortality.

Conclusion

Close monitoring is recommended in this patient group to facilitate a good engraftment outcome.

Impact of the COVID-19 Pandemic on Kidney Diseases Requiring Renal Biopsy: A Single Center Observational Study

Background

The coronavirus disease-2019 (COVID-19) pandemic impacted healthcare services for kidney disease patients. Lockdown and social distancing were mandated worldwide, resulting in closure of medical services. The diagnosis of various kidney diseases may have been delayed during the COVID-19 pandemic because non-urgent tests and visits were postponed due to closure of medical services during the lockdown.

Methods

We here report the impact of the COVID-19 pandemic on a total number of 209 native kidney diseases requiring renal biopsy for diagnosis in a retrospective observational study from a tertiary hospital in Germany.

Results

The lockdown period in March and April 2020 primarily affected patients admitted to the normal medical ward with a compensatory increased rate of renal biopsies in the postlockdown phase. In addition, there was a shift toward more patients admitted with hemoglobinuria during the COVID-19 pandemic. This phenomenon of an increased number of patients with hemoglobinuria during the COVID-19 pandemic was specifically observed in a subgroup with hypertensive nephropathy requiring renal biopsy and associated with increased proteinuria, not attributed to the COVID-19 lockdown period itself.

Conclusion

To our knowledge, this is the first report of identifying a subpopulation susceptible to closure of medical services during the COVID-19 pandemic and diagnostic delay of specific kidney diseases. Therefore, the COVID-19 pandemic should be regarded as a risk factor especially in patients with diseases other than COVID-19 primarily admitted to the normal medical ward.

[Relevance of an accurate microscopic examination of urinary sediment in a patient after mitral valve surgery]

Hemoglobinuria, clinically revealing as gross hematuria associated with anemia, increased hemolysis indices, acute kidney injury (AKI), can all be caused by mechanical intravascular hemolysis following mitral valve surgery. It can result from factors related to the surgical procedure or acquired later, such as paravalvular leak (PL), whose definite diagnosis is based on transesophageal echocardiography. We report the case of a patient who experienced macrohematuria and AKI, initially attributed to acute glomerulonephritis, two months after mitral valve surgery. Careful microscopic examination of the urinary sediment was a diriment diagnostic tool to differentiate acute renal failure caused by hemoglobinuria from hematuria in the course of acute glomerulonephritis, directing clinicians to investigate post-operative valvular dysfunction. From the literature review we can deduce that, notwithstanding new technologies in cardiac surgery, this rare form of AKI from intravascular hemolysis requires immediate nephrological attention and that the use of microscopic urinary sediment is decisive.

A Rare and Misdiagnosed Entity Paroxysmal Nocturnal Hemoglobinuria: A Case Report

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, acquired stem cell disorder manifesting as non-immunological hemolytic anemia, hemoglobinuria, unusual thrombosis, and renal impairment due to deficiency of glycosylphosphatidylinositol (GPI) linked proteins in red blood cells. Patients present with features of chronic non-immune intravascular hemolysis, unexplained anemia, and thrombosis at unusual sites. It is often misdiagnosed and treated as anemia due to a low degree of suspicion. In resource-limited settings, the low degree of suspicion and paucity of investigations are the major diagnostic challenges. The even bigger challenge remains in the affordability of definitive treatment after a diagnosis has been made. Herein, we present a case of PNH in a 26-year man from rural Nepal who went undetected during the initial presentation of hemolytic anemia and later presented to us with hemolytic anemia and gastrointestinal symptoms. We made the provisional diagnosis based on the clinical presentations. However, we faced challenges in reaching the final diagnosis and providing the definitive treatment due to financial constraints and limited resources. Any patient presenting with features of chronic non-immune intravascular hemolysis, unexplained anemia, and unusual thrombosis should prompt the consideration of PNH.

Silicone Oil Decreases Biofilm Formation in a Capacitance-Based Automatic Urine Measurement System

Capacitance-based automatic urine measurement is a validated technique already implemented in clinical practice. However, albuminuria and free hemoglobinuria cause progressive biofilm buildup on the capacitance sensors of the urinometers. The aim of this experimental study is to investigate the influence of albumin and free hemoglobin on the capacitance signal of an automatic urinometer with and without the addition of silicone oil. A solution of Ringer’s acetate mixed with either albumin or free hemoglobin was run through an automatic urinometer containing either a water-soluble capsule with silicone oil or not. In total, around 500 capacitance measurements were retrieved from the albumin and free hemoglobin group, respectively. The mean increase in capacitance in the albumin 3 g/L group was 257 ± 100 pF without and 105 ± 30 pF with silicone oil, respectively, during 24 h. After ten hours of recording, differences between the two albumin groups reached statistical significance. For the free hemoglobin groups (0.01 g/L), the mean increase in capacitance was 190 ± 170 pF with silicone oil, and 324 ± 80 pF without, with a significant difference between the groups after 20 h and onwards. Coating of the capacitance measurement membrane of the automatic urinometer by albumin or free hemoglobin was significantly decreased by silicone oil, prolonging the functionality of the device.

Porcine Babesiosis Caused by Babesia sp. Suis in a Pot-Bellied Pig in South Africa

Babesiosis is a worldwide, tick-borne disease of economic importance in livestock caused by Babesia spp., which are hemoparasitic piroplasms that target the host erythrocytes. Cattle, dogs, small ruminants, and wild ruminants are the species most commonly affected, while in cats, horses, and pigs, it is less frequently reported. Although babesiosis has been observed worldwide, porcine babesiosis remains an uncommon disease with a very limited number of cases reported. Here, we describe a case in a 12-year old pot-bellied pig from South Africa that died after a history of anorexia and reluctance to rise for 2 days. A complete necropsy, blood smear cytology, reverse line blot (RLB) hybridization and 18S rRNA sequencing were performed. Numerous Babesia spp. hemoparasites and a moderate regenerative anemia were identified on blood smear, and a urine dipstick test yielded 4+ heme. Diffuse icterus and splenomegaly were observed upon gross examination. Histopathology revealed hemoglobin casts within renal tubules and collecting ducts, pulmonary edema, splenic congestion, and intrahepatic cholestasis. BLASTN homology of the 18SrRNA sequence revealed a 100% identity to the published sequence of Babesia sp. Suis isolated from pigs in Italy. This case of babesiosis in a pig highlights the clinical manifestations and gross and pathological findings of porcine babesiosis.

Paroxysmal Nocturnal Hemoglobinuria: A Diagnostic "Zero-Sum-Game"

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare intravascular hemolytic anemia caused by an acquired mutation in the phosphatidylinositol-N-acetylglucosaminyltransferase-subunit-A (PIG-A) gene. This mutation leads to the deficiency of cellular anchors for complement inhibitor proteins cluster of differentiation (CD)55 and CD59, predisposing red blood cells to hemolysis by the complement system. We describe the case of a 28-year-old male who presented to the Medical A Ward, Hayatabad Medical Complex, Peshawar, Pakistan, in August 2017 for anemia workup and was later diagnosed as PNH. Current treatment guidelines recommend the use of eculizumab for treating PNH, but the cost and availability of this treatment is a major limiting factor in our resource-poor setting.

Red-Colored Urine in the Cardiac Surgical Patient-Diagnosis, Causes, and Management

Red-colored urine occurring in the intraoperative and early postoperative periods after cardiac surgery is often a cause for concern. This observation may be a result of hematuria from pathology within the urinary tract, anticoagulant-related nephropathy, drug-induced acute interstitial nephropathy, excretion of heme pigment-containing proteins, such as myoglobin and hemoglobin, and hemolysis occurring during extracorporeal circulation. Within the kidneys, heme-containing compounds result in pigment nephropathy, which is a significant contributory factor to cardiac surgery-associated acute kidney injury. Concerted efforts to reduce red blood cell damage during cardiopulmonary bypass, together with early recognition of the at-risk patient and the institution of prompt therapeutic intervention, may improve outcomes. This review addresses the diagnosis, causes, and management of red-discolored urine occurring during and after cardiac surgery.

Acute kidney injury pathology and pathophysiology: a retrospective review

Acute kidney injury (AKI) is the clinical term used for decline or loss of renal function. It is associated with chronic kidney disease (CKD) and high morbidity and mortality. However, not all causes of AKI lead to severe consequences and some are reversible. The underlying pathology can be a guide for treatment and assessment of prognosis. The Kidney Disease: Improving Global Outcomes guidelines recommend that the cause of AKI should be identified if possible. Renal biopsy can distinguish specific AKI entities and assist in patient management. This review aims to show the pathology of AKI, including glomerular and tubular diseases.

ICCS/ESCCA consensus guidelines to detect GPI-deficient cells in paroxysmal nocturnal hemoglobinuria (PNH) and related disorders part 3 - data analysis, reporting and case studies

Over the past several years, a diverse group of physicians and other laboratory scientists have developed various recommendations and guidelines regarding best practices for PNH testing. This manuscript is based on these previous recommendations as well as various other relevant publications of experts in the area of PNH testing. The goal is to provide flow cytometry laboratories with an updated consensus approach to analysis and reporting of PNH results and to address the most common analytical challenges for accurate reporting of this rare disease. A comprehensive case library is included in this section. © 2017 International Clinical Cytometry Society.

Risk factors for hemoglobinuria after ultrasonography-guided percutaneous microwave ablation for large hepatic cavernous hemangiomas

Thermal ablation of large hepatic cavernous hemangiomas may lead to intravascular hemolysis, hemoglobinuria, and even acute renal failure. This study aimed to identify the risk factors associated with hemoglobinuria after ultrasonography-guided percutaneous microwave ablation for large hepatic cavernous hemangiomas. In our study, 11 related risk factors were analyzed using univariate and multivariate binary logistic regression model and Receiver operating characteristic curves to determine the contribution to hemoglobinuria after microwave ablation for 49 patients with 51 hepatic cavernous hemangiomas. By multivariate analysis, the ablation time (p = 0.021; Odds Ratio, 1.005), and the number of antenna insertions (p = 0.036; Odds Ratio, 3.568) were the independent risk factors associated with hemoglobinuria. The cutoff value for ablation time and the number of antenna insertions in predicting the presence of hemoglobinuria was 1185s (sensitivity, 75%; specificity, 69%) and 4.5 (sensitivity, 55%; specificity, 83%), respectively. Less than 5 of antenna insertions and less than 20 mins of ablation time may therefore be recommended in patients with microwave ablation of large hepatic cavernous hemangiomas, in order to reduce the occurrence of hemoglobinuria. This is the first report about the risk factors analysis associated with hemoglobinuria after thermal ablation for large hepatic cavernous hemangiomas.

High Frequency of Blackwater Fever Among Children Presenting to Hospital With Severe Febrile Illnesses in Eastern Uganda

Background

In the Fluid Expansion as a Supportive Treatment (FEAST) trial, an unexpectedly high proportion of participants from eastern Uganda presented with blackwater fever (BWF).

Methods

We describe the prevalence and outcome of BWF among trial participants and compare the prevalence of 3 malaria-protective red blood cell polymorphisms in BWF cases vs both trial (non-BWF) and population controls.

Results

Of 3170 trial participants, 394 (12.4%) had BWF. The majority (318 [81.0%]) presented in eastern Uganda and were the subjects of further analysis. BWF cases typically presented with both clinical jaundice (254/318 [80%]) and severe anemia (hemoglobin level <5 g/dL) (238/310 [77%]). Plasmodium falciparum parasitemia was less frequent than in non-BWF controls, but a higher proportion were positive for P. falciparum histidine rich protein 2 (192/246 [78.0%]) vs 811/1154 [70.3%]; P = .014), suggesting recent antimalarial treatment. Overall, 282 of 318 (88.7%) received transfusions, with 94 of 282 (33.3%) and 9 of 282 (3.4%) receiving 2 or 3 transfusions, respectively. By day 28, 39 of 318 (12.3%) BWF cases and 154 of 1554 (9.9%) non-BWF controls had died (P = .21), and 7 of 255 (3.0%) vs 13/1212 (1%), respectively, had severe anemia (P = .036). We found no association with G6PD deficiency. The prevalence of both the sickle cell trait (10/218 [4.6%]) and homozygous α+thalassemia (8/216 [3.7%]) were significantly lower among cases than among population controls (334/2123 [15.7%] and 141/2114 [6.6%], respectively), providing further support for the role of malaria.

Conclusions

We report the emergence of BWF in eastern Uganda, a condition that, according to local investigators, was rare until the last 7 years. We speculate that this might relate to the introduction of artemisinin-based combination therapies. Further studies investigating this possibility are urgently required.

Acute myeloid leukemia and fatal Scedosporium prolificans sepsis after eculizumab treatment for paroxysmal nocturnal hemoglobinuria: a case report

Eculizumab has become the standard of care for patients with paroxysmal nocturnal hemoglobinuria (PNH). As more patients are treated, the long-term outcomes of these patients will become apparent. We recently treated a patient who developed PNH in the setting of aplastic anemia. The patient developed acute myeloid leukemia less than three years after initiating eculizumab. The patient also died suddenly from Scedosporium sepsis during induction therapy. This patient's course seemed more aggressive than would be expected. The possible effect of complement blockade is discussed.

Expression and function of hematopoiesis-stimulating factor receptors on the GPI- and GPI+ hematopoietic stem cells of patients with paroxysmal nocturnal hemoglobinuria/aplastic anemia syndrome

Paroxysmal nocturnal hemoglobinuria/aplastic anemia (PNH/AA) syndrome presents a markedly increased population of cells deficient in glycophosphatidylinositol (GPI⁻ cells) and signs of bone marrow failure, which requires treatment with hematopoiesis-stimulating factors, such as granulocyte colony-stimulating factor (G-CSF) and stem cell factor (SCF). However, little is known about the effects of these stimulating factors on GPI⁻ cells. In order to explore the effects of stimulating factors in PNH/AA, G-CSF receptor (CD114) and SCF receptor (CD117) expression levels on GPI⁺ and GPI⁻ hematopoietic stem cells (HSCs) were measured by flow cytometry (FCM). The mean fluorescence intensity (MFI) values of signal transducer and activator of transcription 5 (STAT5) and phosphorylated (P)-STAT5 were measured in GPI⁺ and GPI⁻ HSCs by FCM following stimulation with G-CSF or SCF in vitro. The expression levels of CD114 and CD117 on GPI⁻ HSCs were significantly lower (P<0.01) than those on GPI⁺ HSCs in PNH/AA patients and normal controls. The MFI values of STAT5 in the GPI⁻ and GPI⁺ HSCs of PNH/AA patients and normal controls were not significantly different. However, the MFI values of P-STAT5 in the GPI⁻ HSCs of PNH/AA patients were significantly lower than those in the GPI⁺ HSCs of PNH/AA patients and normal controls prior to and following stimulation with G-CSF or SCF (P<0.01). The GPI⁻ HSCs of PNH/AA patients responded poorly to stimulation by hematopoiesis-stimulating factors, which indicates that these factors can be used safely in patients with PNH/AA.

Neutrophil activation and nucleosomes as markers of systemic inflammation in paroxysmal nocturnal hemoglobinuria: effects of eculizumab

BACKGROUND

Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by complement-mediated hemolysis and a high risk of life-threatening venous and arterial thrombosis. Uncontrolled complement activation and the release of cell-free heme may result in systemic inflammation, neutrophil activation, and the release of procoagulant neutrophilic proteases. Eculizumab, an antibody to complement factor C5, inhibits hemolysis and reduces thrombotic risk.

OBJECTIVES

To study neutrophil activation and nucleosome levels in relation to thrombosis in PNH patients before and during treatment with eculizumab.

PATIENTS/METHODS

In 51 untreated PNH patients, including 20 patients before and after commencing eculizumab treatment, we have assessed neutrophil activation by measuring elastase-α1 -antitrypsin (EA) complexes and circulating nucleosomes, as established markers for systemic inflammation and cell death.

RESULTS

Nucleosomes (median; range; 95% confidence interval [CI]), but not EA complexes, were higher in PNH patients with a history of thrombosis (16; 7-264; 0.3-94 U mL(-1) , n = 12) than in those without (6; 6-35; 7-11 U mL(-1) , n = 39) or controls (8; 6-23; 7-12 U mL(-1) , n = 17). EA complexes, but not nucleosomes, decreased promptly and markedly upon eculizumab treatment. EA complexes (estimated marginal means; 95% CI) remained low at ≥ 12 weeks (50; 34-67) compared with baseline (12; -6 to 29).

CONCLUSIONS

The increased nucleosome levels in PNH patients with a history of thrombosis suggest systemic inflammation and/or cell death. Neutrophil activation markers did not differ between patients with and without a history of thrombosis and healthy controls. Interestingly, basal neutrophil activation in PNH patients significantly decreases on treatment with eculizumab, indicating that neutrophil activation is C5a driven.

Pathophysiology, diagnosis, and treatment of paroxysmal nocturnal hemoglobinuria: a review

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired disorder of the hematopoietic stem cell that makes blood cells more sensitive to the action of complement. Patients experience intravascular hemolysis, smooth muscle dystonia, renal failure, arterial and pulmonary hypertension, recurrent infectious diseases and an increased risk of notably dreadful thrombotic complications. The diagnosis is made by flow cytometry. Efforts have been recently performed to improve the sensitivity and the standardization of this technique. PNH is frequently associated with aplastic anemia or low-risk myelodysplasia and may be asymptomatic. Management of the classical form of PNH has been dramatically revolutionized by the development of eculizumab, which brings benefits in terms of hemolysis, quality of life, renal function, thrombotic risk, and life expectancy. Prophylaxis and treatment of arterial and venous thrombosis currently remain a challenge in PNH.

Hemoglobinuria misidentified as hematuria: review of discolored urine and paroxysmal nocturnal hemoglobinuria

Discolored urine is a common reason for office visits to a primary care physician and urology referral. Early differentiation of the type or cause of discolored urine is necessary for accurate diagnosis and prompt management.

Paroxysmal nocturnal hemoglobinuria is a clonal disorder caused by acquired somatic mutations in the PIG-A gene on the X- chromosome of hemopoietic stem cells and leads to deficiency of surface membrane anchor proteins. The deficiency of these proteins leads to an increased risk of hemolysis of erythrocytes and structural damage of platelets, resulting in a clinical syndrome characterized by complement-mediated intravascular hemolytic anemia, bone marrow failure, and venous thrombosis. Patients with this clinical syndrome present with paroxysms of hemolysis, causing hemoglobinuria manifesting as discolored urine. This can be easily confused with other common causes of discolored urine and result in extensive urologic work-up. Three commonly confused entities of discolored urine include hematuria, hemoglobinuria, and myoglobinuria. Specific characteristics in a dipstick test or urinalysis can guide differentiation of these three causes of discolored urine.

This article begins with a case summary of a woman presenting with cranberry-colored urine and a final delayed diagnosis of paryxysmal nocturnal hemoglobinuria. Her hemoglobinuria was misdiagnosed as hematuria, leading to extensive urologic work-up. The article also gives an overview of the approach to diagnosing and treating discolored urine.

Pathogenesis of acute kidney injury: foundation for clinical practice

The pathogenesis of acute kidney injury (AKI) is complex, involving such factors as vasoconstriction, leukostasis, vascular congestion, cell death, and abnormal immune modulators and growth factors. Many targeted clinical therapies have failed, are inconclusive, or have yet to be tested. Given the complexity of the pathogenesis of AKI, it may be naive to expect that one therapeutic intervention would have success. Some examples of detrimental processes that can be blocked in preclinical models to improve kidney function and survival are apoptotic cell death in tubular epithelial cells, complement-mediated immune system activation, and impairment of cellular homeostasis and metabolism. Modalities with the potential to decrease morbidity and mortality in patients with AKI include vasodilators, growth factors, anti-inflammatory agents, and cell-based therapies. Pharmacologic agents that target these diverse pathways are being used clinically for other indications. Using combinatorial approaches in future clinical trials may improve our ability to prevent and treat AKI.

Sensitivity of routine tests for urine protein to hemoglobin

Increasing concentrations of canine hemoglobin were added to aliquots of urine and saline to determine the relative sensitivity of several hemoglobin and protein detection methods including commercial reagent strips and sulfosalicylic acid. The hemoglobin detection pads of the reagent strips were 50 times more sensitive than the protein detection pads, indicating the presence of hemoglobin at a concentration of 0.001 g/L whereas the protein pads did not react positively unless the hemoglobin concentration exceeded 0.05 g/L. The sulfosalicylic acid test was the least sensitive, detecting hemoglobin only at concentrations of 0.4 g/L or higher. These results were similar for hemoglobin added either in the form of lysed red blood cells, intact red blood cells or associated with plasma proteins in whole blood.It was shown that a urine hemoglobin concentration eliciting less than the maximal score on the hemoglobin detection pad will not be detected as "protein" either with the commercial urinalysis strips or with sulfosalicylic acid. It was also seen that hemoglobin becomes visible as a red pigment when exceeding 0.3-0.5 g/L in a clear, light urine. It follows that a positive urine protein reading in the presence of a positive but less than maximal hemoglobin score or a protein reading exceeding 1.0 g/L in a nonpigmented urine indicates "true" proteinuria in excess of hemoglobin and plasma proteins associated with urinary tract hemorrhage.