Mechanisms of adverse effects during hemapheresis

A nomogram prediction of citrate reaction during mononuclear cell collection in solid tumor patients

PURPOSE

Citrate reaction is one of the main adverse events in peripheral blood mononuclear cell (MNC) collection. The aim of this study was to elucidate the risk factors for citrate reaction in patients with advanced solid tumor collection and to construct a nomogram to predict the risk.

METHODS

One hundred forty-eight patients with advanced solid tumor who underwent peripheral blood MNC collection in our hospital between January 2021 to December 2021 were selected. The general data, creatinine level before collection, Ca²⁺ concentration before collection, absolute value of monocyte lymphocytes before collection, circulating blood volume, anticoagulant dosage, and blood collection duration were included in Logistic regression analysis to identify the risk factors of citrate reaction. According to the results of the multivariate logistic model, nomogram was established and receiver operating characteristic (ROC) curve was drawn to evaluate the predictive value of the model.

RESULTS

Among the 148 solid tumor patients, 35 patients (23.6%) of the 148 patients developed citrate reaction. Multivariate analysis showed that the risk factors for citrate reaction in the process of collection included sex (odds ratio [OR] = 6.718; 95% confidence interval [95% CI]: 2.191-20.594, P = .001), age (OR = 0.957; 95% CI: 0.921-0.996, P = .03), and processed circulating blood volume (OR = 1.001; 95% CI: 1.000-1.002, P = .01). Logistic regression can analyze independent risk factors and establish risk prediction model. The predictive performance of the model is good, and the area under ROC curve is 0.799.

CONCLUSIONS

The MNC collection process is safe. The incidence of citrate reaction in the collection of peripheral blood MNCs from patients with advanced solid tumor is related to the age, gender, and processed circulating blood volume of patients. The nomogram can be used to assess a patient's risk of citrate reaction.

Report of plasma exchange in a rare case of association of myasthenia gravis with thymoma and parathyroid adenoma

Myasthenia with thymoma and parathyroid adenoma is a rare presentation. Very few cases have been reported of this association without much role of plasma exchange in these patients. Here, we present our experience of plasma exchange in this rare clinical entity.

Serial monitoring of ionised calcium levels in plateletpheresis donors: A study from tertiary care oncology centre in India

BACKGROUND

Plateletpheresis is a safe procedure, and the most common reaction is hypocalcemia which is transient and self-limiting, but it can have an impact on donor experience and donor return rate.

AIM

To serially monitor the ionized calcium levels of the plateletpheresis donors and to correlate with symptoms of hypocalcemia if any.

METHODS

It was a prospective observational study in 126 healthy voluntary donors eligible for plateletpheresis as per the Departmental SOP and after taking written informed consent. Procedures were conducted on continuous flow centrifugation (CFC) and intermittent flow centrifugation (IFC) cell separators. Donor blood samples were collected in pre-heparinized syringes at different intervals to measure ionized calcium levels (iCa++) by venous blood gas analysis (Cobas 221).

RESULTS

There was a continuous and gradual decrease in iCa++ from start to 30-45 minutes during the procedure; while the levels showed a gradual increase at end of the procedure and reached near the baseline values after 15-30 min of completion of the procedure. The change in iCa++ was statistically significant at 30 min and 45 min (p < 0.05), which was correlated with symptoms of hypocalcemia observed in 32.5 % (41/126) of the donors. Females experienced more symptoms of hypocalcemia as compared to males (p < 0.01). Donors who underwent plateletpheresis on the IFC machine experienced more symptoms of hypocalcemia as compared to the CFC machine (p < 0.05).

CONCLUSION

For donors with persistent symptoms of hypocalcemia which are unrelieved by procedural modifications (reducing blood return rate, citrate infusion rate, etc.) measurement of iCa++ and administration of oral calcium tablets may be considered.

Alteration in biochemical parameters during plateletpheresis in healthy donors: A compendious analysis

OBJECTIVES

During plateletpheresis, citrate induces hypocalcemia and hypomagnesemia, which are usually transient and self-limiting, but they can lead to significant donor discomfort. The aim of study was to determine the effect of citrate infusion on a multitude of biochemical parameters during plateletpheresis in healthy donors and to correlate changes with adverse donor reactions.

METHODS

The study was conducted on 60 healthy plateletpheresis donors. Blood samples were drawn on three occasions, a baseline pre-donation sample, 30min at start of procedure and 30min post procedure. Heparinized samples were taken to measure ionized calcium and plain samples to measure serum calcium, serum magnesium, parathyroid hormone, total protein and serum albumin.

RESULTS

There was statistically significant decline in mean total calcium (9.27±0.66mg/dl to 8.72±0.87mg/dl) and ionized calcium (3.8±0.51mg/dl to 2.9±0.67mg/dl) from baseline until 30min after the start of procedure respectively. A significant fall in serum magnesium, total protein and serum albumin was observed. The mean parathyroid hormone showed significant increase from baseline levels till at the completion of procedure (19.94±12.1pg/ml to 92.08±36.78pg/ml). If the yield was set constant, there was negative correlation between ACD used and pre-donation platelet count. Majority of adverse donor reactions were hypocalcemic reactions, which were more with Amicus double yield plateletpheresis and were managed with calcium supplementation.

CONCLUSION

Plateletpheresis induces marked reduction in serum calcium and magnesium levels. Moreover, increase in parathyroid hormone levels was significant. In addition, decline in total protein and serum albumin may be a concern in donors also participating in plasmapheresis.

Prophylactic administration of oral calcium carbonate during plateletpheresis: A bicentric prospective study

BACKGROUND:

Administration of anticoagulant citrate and dextrose (ACD-A) chelates ionized calcium in blood and causes hypocalcemia in plateletpheresis donors. The aim of the study was to observe the effects of oral calcium (Ca) supplementation during plateletpheresis on various parameters related to calcium metabolism.

MATERIALS AND METHODS:

This study was performed between January 2014 and December 2014 on 200 plateletpheresis donors. They were divided into two groups. In group A donors (n=100), no prophylactic oral calcium supplementation was given. In group B (n=100) donors, 2000 mg of calcium was given one hour before the start of the procedure, 500 mg was given at the start of the procedure and 500 mg calcium was given just before the end of procedure. Biochemical parameters like serum total calcium (T Ca), serum total magnesium (T Mg) and ionized calcium level (iCa) were measured before and after the procedure. Relative risk of citrate toxicity was measured between the two groups.

RESULTS:

There was a significant fall in total calcium (pre 9.02 mg/dl, post 8.23 mg/dl,), ionized calcium level (pre 1.14 mmol/L, post 0.91 mmol/L) and total magnesium (pre 1.92 mg/dl, post 1.79 mg/dl) amongst the donors who did not receive prophylactic calcium supplementation. Despite calcium intake, in prophylactic calcium intake group, we did observe a significant drop in total magnesium (pre 2.04 mg/dl, post 1.94 mg/dl) and ionized calcium level (pre 1.25 mmol/L, post 1.12 mmol/L, p<0.01). We did observe a drop in total calcium level, however, this observation was not statistically significant. The risk (RR=5.44) of citrate toxicity was higher among group A donors.

CONCLUSION:

Prophylactic oral calcium carbonate supplementation would help in to reduce the risk of citrate toxicity. Therefore, we suggest for prophylactic oral administration of 3000 mg elemental calcium carbonate in three divided doses to make PP procedures uneventful.

The Play of Citrate Infusion with Calcium in Plateletpheresis Donors

Citrate is the anticoagulant of choice for plateletpheresis. Citrate toxicity is common during plateletpheresis as citrate chelates calcium and causes hypocalcemia in donors. We have conducted this study to analyze the effects of routine citrate infusion during plateletpheresis on laboratory and clinical parameters. We also compared the dose of citrate delivered to donors during plateletpheresis using two different cell separators as Haemonetics MCS + and Trima Accel. The study was conducted on 50 plateletpheresis donors who were eligible for donation. Donor demographics and baseline parameters were recorded. Pre, mid and post-procedure blood samples were collected for hematological and biochemical analysis. We found a significant decrease in baseline iCa (1.23 ± 0.07 mmol/L) from start to mid-procedure (1.19 ± 0.006 mmol/L) which recovered at 30 min post procedure (1.2 ± 0.01 mmol/L). The incidence of citrate toxicity was 10%. In donors with citrate toxicity, the post-procedure recovery of iCa was not seen and there was a further decrease in iCa levels. We also found a significant fall in Hb and platelet count post plateletpheresis. We observed that lower PLT counts (< 200 × 10³/µL) necessitated higher blood volume processing and therefore a higher anticoagulant (citrate) dose. The Trima Accel cell separator reached platelet target yield faster but with a higher citrate dose as compared to Hemonetics MCS + . Ionized calcium decreases significantly during plateletpheresis but recovers soon after the completion of the procedure. Serious adverse events were not observed during plateletpheresis. The mild citrate toxicity which occurred was easily managed by slowing the procedure and administering oral calcium to donors. Trima Accel and Hemonetics MCS + both collected platelets efficiently, with minimal donor discomfort.

A liquid calcium+vitamin D3 supplement is effective prophylaxis against hypocalcemic toxicity during apheresis platelet donation

Hypocalcemic toxicity, because of return of citrate anion to the donor, is the major toxicity of apheresis platelet donation. Oral calcium carbonate, given prophylactically at the start of donation, has shown limited ability to alleviate this toxicity. We examined whether repeated prophylactic doses of calcium carbonate, or of a liquid preparation containing calcium citrate, calcium phosphate, and vitamin D₃ , would be more effective at preventing symptoms of hypocalcemic toxicity. Symptoms were reported by 48% of donors who received no prophylaxis and 60% of donors who received 1000 mg of oral calcium carbonate at the start of, and every 20 minutes during, donation (P = 0.711). Only 19.2% of donors who received the liquid preparation (1000 mg calcium, 1000 IU vitamin D₃ ) reported symptoms (P = 0.040 versus no prophylaxis, P = 0.039 versus calcium carbonate). This difference was not because of gender, weight, age, or blood volume of the donor. Neither calcium preparation prevented a measurable fall in plasma ionized calcium during donation. We conclude that liquid calcium citrate/calcium phosphate/vitamin D₃ provides effective prophylaxis against hypocalcemic toxicity during platelet donation, however it does not prevent a fall in plasma ionized calcium.

Citrate anticoagulation: Are blood donors donating bone?

An estimated 2.4 million volunteer apheresis blood donation procedures were performed in the United States in 2010, and increases in the proportion of transfused blood products derived from apheresis blood collections have been consistently reported. Anticoagulation is required during apheresis and is achieved with citrate. Donor exposure to citrate causes an acute physiological response to maintain serum mineral homeostasis. Some data are available on the sequelae of this acute response in the days and weeks following exposure, raising questions about bone mineral density in regular apheresis donors. New research is emerging that addresses the potential long-term health outcomes of repeated citrate exposure. This article reviews the acute physiological response to citrate anticoagulation in volunteer blood donors, presents contrasting perspectives on the potential effects of citrate exposure on bone density, and identifies key knowledge gaps in our understanding of long-term health outcomes in apheresis donors. J. Clin. Apheresis 31:459-463, 2016. © 2015 Wiley Periodicals, Inc.

Comprehensive analysis of changes in clinically significant divalent serum cation levels during automated plateletpheresis in healthy donors in a tertiary care center in North India

BACKGROUND

Adverse effects due to apheresis are unusual. The most common apheresis-specific reaction is hypocalcemia due to citrate anticoagulation and induces ionized hypocalcemia and hypomagnesemia by chelating effect during the plateletpheresis; generally transient and self-limiting but has the potential of severely injuring donor. We have investigated total calcium (tCa(++)) and magnesium (tMg(++)) levels in sixty healthy plateletpheresis donors at different intervals during the procedure and 30 min post-procedure.

MATERIALS AND METHODS

A total of 60 procedures were performed on healthy donors. Blood samples were obtained from sterile diversion pouch placed on apheresis circuit. 5 ml sample in plain vials was obtained at different intervals during each procedure and 30 min after the end of the procedure. Samples were used for measurement of tCa(++) and tMg(++) levels.

RESULTS

There is continuous decrease in mean tCa(++) from baseline levels (9.83 ± 0.64 mg/dl) till end of procedure (8.33 ± 0.78 mg/dl), but after 30 min, levels again reached near their respective baseline values (9.42 ± 0.54 mg/dl). Similarly, mean tMg(++) fell from baseline levels (2.36 ± 0.3 mg/dl) till the end of procedure (1.39 ± 0.40 mg/dl). After 30 min, levels were again increased, their respective baseline values (2.25 ± 0.25 mg/dl).

CONCLUSION

There is continuous, gradual, and significant fall (P < 0.05) in mean tCa(++) and mean tMg(++) from baseline levels to till the end of procedure but after 30 min of completion of procedure, levels again reached near their respective baseline values.

The relationship of platelet yield, donor's characteristic and apheresis instruments in China

Platelet yield was associated with donor's characteristic and property of apheresis instruments. Here, we have analyzed the relationship of platelet yield, physiologic parameters of donors for different apheresis instruments in China. Data were consecutively retrieved from plateletapheresis donors during March 1, 2007 and March 1, 2012. Three different apheresis instruments MCS+, Amicus, Trima system were used for plateletapheresis and defined as group 1, 2 and 3 respectively. Totally 77,091 Plateletapheresis donations were performed in this study. 17 donations were finally aborted because of vasovagal reaction with syncope. 5861, 37,036, 34,177 donations were performed in group 1, 2 and 3 respectively. Hct and platelet values before donations were similar, but platelet yield and collection rate were showed significantly difference (p<0.05) among the three groups. The values of platelet and Hct in the males before donations were higher than those in the females, and the platelet yield and collection rate were showed significantly difference between the male group and female group (p<0.05). The overall reaction rate was 1.56%. Most donors were chosen the group 2 (51.6%) for next donation, followed by group 3 (33%) and group 1 (15.4%). We concluded that the platelet yield and collection rate in the male group were higher than those in the female group and the efficiency of plateletapheresis was associated with the kind of apheresis instruments and donor's characteristic. These data will help to work out suitable apheresis protocol based on the Chinese donor's characteristic.

Adverse reactions during voluntary donation of blood and/or blood components. A statistical-epidemiological study

BACKGROUND

Voluntary donors normally tolerate blood donation very well, but, occasionally, adverse reactions of variable severity may occur during or at the end of the collection. Aim of this study was to estimate and possibly avoid the cause of unwanted reactions.

MATERIALS AND METHODS

The study was conducted over a period of 6 months, from 24(th) October, 2005 to 24(th) April 2006. The donor population analysed consisted of 4,906 donors (3,716 male and 1,190 female). In total, 3,983 (81%) voluntaries have donated whole blood, 851 (17%) plasma from apheresis, 64 (1.3%) experienced multicomponent donation, and 8 (0.1%) were donors of plasma-platelet apheresis.

RESULTS

Only 63 donors (1.2% of all the volunteers) suffered some kind of adverse reaction: 59 (1.08% of the subjects) had mild reactions (agitation, sweating, pallor, cold feeling, sense of weakness, nausea), and only 4 (3 males and 1 female, 0.2%) had more severe disorders, including vomiting, loss of consciousness, and convulsive syncope.

CONCLUSIONS

Although the number of donors who developed disturbances during or at the end of blood donations was very low, it is nevertheless desirable to reduce risks to a minimum. A set of advices is provided for preventing problems.

Anticoagulation techniques in apheresis: from heparin to citrate and beyond

Anticoagulation is essential for maintaining the fluidity of extravascular blood on the apheresis circuit. Although both citrate and heparin are used as an anticoagulant during apheresis, citrate is preferred for the majority of exchange procedures because of its safety and effectiveness. Complications of citrate are primarily due to physiologic effects of hypocalcemia. Symptoms of hypocalcemia and other citrate-induced metabolic abnormalities affect neuromuscular and cardiac function and range in severity from mild dysesthesias (most common) to tetany, seizures, and cardiac arrhythmias. Oral or intravenous calcium supplementation is advised for decreased ionized calcium levels and/or symptomatic management of hypocalcemia. Heparin-based anticoagulation is limited to certain apheresis procedures (membrane-based plasma exchange, LDL apheresis, or photopheresis) or is used in combination with citrate to reduce citrate load. While effective, heparin anticoagulation is associated with an increased frequency of bleeding complications and heparin-induced thrombocytopenia. J. Clin. Apheresis 2012. © 2012 Wiley Periodicals, Inc.

Increased risk of citrate reactions in patients with multiple myeloma during peripheral blood stem cell leukapheresis

The citrate based anticoagulant ACD is commonly used in apheresis procedures. Due to its ability to decrease ionized calcium, citrate may cause unpleasant symptoms, such as paresthesias and muscle cramps, in patients undergoing therapeutic and donor apheresis. We noticed that patients with multiple myeloma (MM) undergoing autologous stem cell leukapheresis appeared to have more citrate reactions when compared to other patients undergoing the same procedure. A retrospective chart review was performed to evaluate 139 (of 151) consecutive patients with MM, amyloidosis, hematological and solid malignancies who had autologous peripheral blood stem cell collection between January 2007 and February 2008. Citrate reactions, ranging from mild (e.g., perioral tingling and parasthesias) to severe (e.g., nausea/vomiting and muscle cramps) were noted for 35 patients. Twenty-three of 63 patients with MM had documented citrate reactions, which was significantly higher than those with other hematological and solid malignancies (37% vs. 20%; P < 0.05, Relative Risk (RR) = 1.9). The severities of citrate reactions were the same in both groups; approximately 50% of patients in each group received i.v. calcium gluconate for treatment of hypocalcemia. No correlation between bisphosphonate therapy and citrate reactions were noted in our study group. Examination of available laboratory values related to calcium homeostasis, liver, and renal function failed to reveal a mechanism for the increase in citrate reactions observed. In summary, this single institution retrospective study indicates that patients with MM are more sensitive to citrate-induced hypocalcemia during leukapheresis when compared to patients with other hematological and solid malignancies. Strategies for decreasing citrate reactions (e.g., supplemental calcium and slowing return rates) should be considered for patient safety and comfort, especially in the MM population, on a prophylactic rather than reactive basis.

Postthaw clotting of peripheral blood stem cell products due to insufficient anticoagulant

The amount of acid citrate dextrose formula A (ACD-A), which is a commonly used anticoagulant in leukopheresis, has to ensure both the safety of the donor and guarantee the integrity of the peripheral blood stem cell (PBSC) product until its transplant. Two recent consecutive cases of postthaw PBSC product clotting initiated a look-back investigation of the ACD-A percentage in leukopheresis products collected in our facility. The data indicated a significant difference between the average amount of ACD-A in prefreezing products collected during 2006 (11.4%) and in products collected during 2007 and 2008 (8.8% and 8.7%, respectively). These findings and the fact that the two clotted products had less than 7% ACD-A indicated that insufficient amount of anticoagulant might contribute to their clotting. This investigation prompted us to modify our collection and thawing procedures to prevent similar events in the future.

Adverse reactions in blood and apheresis donors: experience from two Italian transfusion centres

BACKGROUND

Blood and apheresis donations are widely considered to be safe with a low incidence of adverse reactions and injuries; however, data reported in the medical literature on the prevalence of adverse events in donors and studies on the predictive risk factors for donor reactions are limited and contradictory.

METHODS

From January 2002 to December 2006 we recorded every adverse reaction verified during 240,596 consecutive blood and apheresis donations (183,855 homologous whole blood donations, 6,669 autologous whole blood donations, 38,647 plasmapheresis, 2,641 plateletpheresis and 8,784 multicomponent donations) at the Italian Transfusion Centres of Verona and Ragusa,.

RESULTS

Using a special, pre-arranged form within the quality system, a total of 686 adverse reactions (related to 0.28% of all donations) were recorded. Vasovagal reactions, mostly of mild intensity, were the most commonly observed adverse reactions, with a frequency of 0.20% (487/ 240,596). The frequency of the vasovagal reactions varied according to the different types of donation, being 0.19% (346/183,855) for homologous whole blood donations, 0.24% (16/6,669) for autologous whole blood donations, 0.16% (63/38,647) for plasmapheresis, 0.68% (18/2,641) for plateletpheresis and 0.49 (43/8,784) for multicomponent donations. Citrate toxicity was reported in 0.38% (189/50,072) of apheresis donations. Severe adverse reactions were very rare, as they occurred in 0.004% of the donations (10/240,596).

CONCLUSIONS

In conclusion, the results of our 5-year survey document that apheresis and blood donation are safe procedures for the donor with a low incidence of adverse reactions; the adverse reactions that did occur were mostly mild and resolved rapidly.

Complications of donor apheresis

A decreasing blood donor pool in the presence of increasing blood transfusion demands has resulted in the need to maximally utilize each blood donor. This has led to a trend in the increasing use of automated blood collections. While apheresis donation shares many reactions and injuries with whole blood donation, because of the differences, unique complications also exist. Overall, evidence in the literature suggests that the frequency of reactions to apheresis donation is less than that seen in whole blood donation, though the risk of reactions requiring hospitalization is substantially greater. The most common apheresis-specific reaction is hypocalcemia due to citrate anticoagulation, which, while usually mild, has the potential for severely injuring the donor. Other reactions to apheresis donation are uncommon (e.g., hypotension) or rare (e.g., air embolism). More worrisome, and in need of additional study, are the long-term effects of apheresis donation. Recent evidence suggests that repeated apheresis platelet donations may adversely effect thrombopoiesis as well as bone mineralization. Granulocyte donation has also been implicated in unexpected long-term consequences.

Profound ionized hypomagnesemia induced by therapeutic plasma exchange in liver failure patients

BACKGROUND

Various adverse effects, including cardiac arrest, have been induced by plasma exchange (PE). Electrolyte derangement is frequently observed. The purpose of this study was to assess the effect of PE on the serum ionized magnesium (Mg2+) concentration in acute liver failure patients.

STUDY DESIGN AND METHODS

Seven liver failure patients requiring PE were enrolled in this study. PE was performed 21 times in total. Blood samples were drawn before PE and serially after the start of the PE. Serum Mg2+ was measured by the ion- selective electrode method.

RESULTS

After PE was started, Mg2+ concentrations began to fall significantly. The low Mg2+ blood concentration continued during PE. After PE, the Mg2+ level recovered to about 80 percent of the control value within 2 hours in six patients. However, in one patient, the Mg2+ concentration was still low even at 2 hours after PE. This patient complained of chest discomfort during PE and ECG analysis showed sporadic supraventricular premature contractions.

CONCLUSION

Profound ionized hypomagnesemia was induced by PE in liver failure patients.

A pilot study of large volume apheresis of red blood cells and plasma during one donation by allogeneic blood donors

As a pilot study, we assessed large volume apheresis of red blood cells (RBC) and plasma. The protocol was as follows: (a) 3-RBC group: 3 units (240 ml) of RBC were drawn, (b) RBC+P group: 2 units (160 ml) of RBC and 400 ml of plasma were drawn during one apheresis procedure, and (c)

CONTROL GROUP

400 ml of whole blood was drawn by a manual method. Each group contained 7 healthy male donors of body weight 54-65 kg. We were able to perform these apheresis procedures without serious complications. Recovery of RBC for the donors of the 3-RBC group was delayed, but the level returned to the pre-donation level within nine weeks. The decreased total protein and albumin in the RBC+P group recovered within one week. The apheresed RBCs demonstrated the same quality as the manually collected RBC. These findings suggest that this apheresis approach may be applicable for routine donation.

Electrolyte monitoring in patients undergoing peripheral blood stem cell collection

In recent years peripheral blood stem cell (PBSC) collection for allogeneic or autologous transplantation has experienced an increased use in the onco-hematological setting. The latest generation cell separators allow a satisfactory and safe PBSC collection. Nevertheless, as in all therapeutic apheresis procedures, patients may experience procedure-related side-effects, mainly vasovagal reactions or symptoms related to hypocalcemia and/or hypomagnesemia. We investigated electrolyte changes in 18 patients, with a median age of 46 years (range 7-62), undergoing PBSC collection from January to April 1998. A significant decrease in total calcium in the final sample (9.65 +/- 0.7 mg/dL) with respect to the basal one (9.2 +/- 0.6 mg/dL, P < 0.05) was observed; also ionized calcium decreased markedly from the first sample drawn at +30 minutes: 1.22 +/- 0.14 vs. 1.03 +/- 0.15 mmol/L (P < 0.05), and a highly significant difference emerged when basal value were compared to the final value: 1.22 +/- 0.14 vs. 0.94 +/- 0.13 mmol/L (P < 0.0001). Similar findings affected potassium concentration: 4.1 +/- 0.4 vs. 3.3 +/- 0.3 mEq/L (P < 0.0001). Three out of eighteen patients (16.7%) reached a final potassium level <3.0 mEq/L, and eight out of eighteen (44.5%) showed a potassium concentration decrease >20% with respect to the basal value. A mild metabolic alkalosis occurred during the procedure: pH increased from 7.35 +/- 0.02 to 7.43 +/- 0.028 (P < 0.001), and plasma bicarbonate concentration increased from 27.48 +/- 2.21 to 32.44 +/- 2.52 mmol/L (P < 0.01). Sodium and chloride did not differ in the final sample with respect to the basal sample. None of our patients experienced clinically relevant side effects related to severe electrolyte changes (i.e., >20% with respect to the basal value). Because our current therapeutic schedules include patients older than 50 years in the PBSC collection and transplantation program and since it is well known that subclinical myocardial disease may occur in up to 4% of middle-aged males, we suggest that patients aged 50 or older undergoing PBSC collection procedures be carefully monitored in order to identify significant electrolyte variation, especially if they present with low serum potassium levels. However, further investigation of larger patient series are needed to determine the clinical relevance of serum potassium changes during apheresis.

Cryofiltration apheresis and plasma fractionation causing anaphylactoid reactions in patients receiving angiotensin converting enzyme inhibitors

Severe anaphylactoid reactions and even death have been reported in hemodialysis patients using certain membrane dialyzers while receiving angiotensin converting enzyme (ACE) inhibitors. We report mild to moderate anaphylactoid reactions in 4 patients receiving plasmapheresis with on-line membrane filters after being placed on ACE inhibitors. Of 21 patients receiving 497 plasma fractionation procedures, only the 2 patients who were receiving ACE inhibitors developed anaphylactoid reactions. Of 28 patients who had 680 cryofiltration procedures, only 2 of 5 patients who were taking ACE inhibitors developed anaphylactoid reactions. All patients developed facial flushing, increased warmth, bradycardia, and hypotension after approximately 1/2 to 1 L of plasma was processed during the procedures. Only a few procedures caused severe hypotension requiring discontinuation of the procedure. We quantified vasodilatory mediators in 1 patient, who developed pronounced symptoms. Results were obtained for 6-keto PGF1alpha, PGD-M, and methyl histamine in plasma. In addition, in the same patient, 2,3 dinor 6-keto PGF1alpha and methyl histamine were quantified in urine samples. Our results showed that plasma and urinary metabolites were not grossly elevated although they did increase slightly. Mild to moderate anaphylactoid reactions were observed in some patients on ACE inhibitors receiving plasma fractionation or cryofiltration apheresis. This was resolved by discontinuing either the ACE inhibitor, plasma fractionation, or cryofiltration apheresis.