Reversible melphalan-induced lung damage

CASE REPORTS

Reversible Melphalan-Induced Lung Damage

BYRON T. WESTERFIELD, M.D. JOSEPH P. MICHALSKI, M.D. CANDACE MCCOMBS, Ph.D. RICHARD W. LIGHT, M.D. Long Beach, California

Pulmonary toxicity occurs after the administration of several different chemotherapeutic agents. Pulmonary toxicity due to melphalan alone has not been documented. In the patient we describe res iratory symptoms and pulmonary infiltrates developed twice wit Ein two weeks of the second course of a monthly melphalan and prednisone regimen. Open lung biopsy revealed interstitial pneumon‘itis. The infiltrates cleared on both occasions when melphalan was withheld. Special studies performed seven weeks after the last dose of melphalan had been given revealed that the patient’s alveolar macrophages suppressed phytohemagglutinin induced blastogenesis of his peripheral lymphocytes. Melphalan itself did not stimulate the blastogenesis of the peripheral lymphocytes. Melphalan should be added to the list of therapeutic agents that induce pulmonary disease. However, the pathogenesis of the disease remains to be elucidated. Pulmonary toxicity due to antineoplastic chemotherapeutic agents is an increasingly serious problem. Both the variety of processes which occur in these patients and the widespread use of numerous antitumor drugs complicate the clinical picture. Busulfan [l], cyclophosphamide [2], bleomycin [3,4], methotrexate [5], chlorambucil[6] and, more recently, bischloroethylnitrosourea [7,8] have all been shown to cause parenchymal pulmonary disease. A possible association between melphalan and pulmonary fibrosis has been suggested [9,10] but, despite the widespread use of this agent, no definite pulmonary toxicity from melphalan alone has been reported. We report here a reversible pulmonary reaction resulting from this agent. CASE REPORT

From the Department of Medicine, Veterans Administration Medical Center, Long Beach and the University of California, Irvine, California. Requests for reprints should be addressed to Dr. Richard W. Light, Chief, Pulmonary Diseases. Veterans Administration Medical Center. 5901 East 7th Street, Long Beach, California 90822. Manuscript accepted July 24.1979.

A 75 year old white man with a one week history of cough, chills and fever was admitted. His past medical history was remarkable for a hematologic disorder characterized by anemia and a monoclonal gammopathy initially documented two and a half years previously. Serial immunoglobulin assays revealed persistently elevated immunoglobulin G (IgG) levels with depressed immunoglobulin A (IgA) and immunoglobulin M (IgM). Repeated bone marrow biopsy specimens demonstrated more than 5 per cent plasma cells: Bence Jones proteins were absent. The presumptive diagnosis was multiple myeloma. Because of symptomatic anemia, the patient wasgiven chemotherapy which consisted of melphalan, 10 mg/day, and prednisone, 120 mg/day; both were given for four days at monthly intervals. The patient had a pack/day smoking history of greater than 50 years but quit several years previously; he had no industrial exposure. The lung fields were clear on chest roentgenogram prior to melphalan therapy.

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Figure 2. Lung biopsy specimen demonstrating interstitial mononuclear cell infiltration and early fibrosis. Hematoxylin and eosin stain; magnification X40, reduced by 46 per cent.

Figure 1. Posteroanterior chest roentgenogram obtained on admission showing bilateral interstitial infiltrates.

Ten days following the patient’s second course of chemotherapy, a nonproductive cough, fever and malaise developed. Oral ampicillin was prescribed. Four days later, the patient was admitted because the fever and cough had persisted, and left-sided pleuritic chest pain and confusion had developed. On admission physical examination revealed a pale, elderly man without distress. His pulse rate was 168/min, the respiratory rate was 26/min, and the temperature was 99% orally. The heart rate was regular with an atria1 gallup. Auscultation of the lungs revealed bibasilar end-inspiratory crackles. The liver size was normal and the spleen was not palpable. Initial laboratory data included a hemoglobin level of 8.3 g/100 ml: white blood cell count 4,466/mm3 with 51 per cent polymorphonuclear leukocytes, 16 per cent band forms and 10 per cent eosinophils. Arterial blood gases on room air were hydrogen ion concentration (pH) 7.4, arterial oxygen tension (PaOs) 56 Torr and carbon dioxide tension (Pc0.J 28 Torr. The serum protein was 5.3 g/166 ml, albumin 2.8 g/166 ml and blood urea nitrogen 25 mg/166 ml. Electrolytes, clotting studies and urinalysis were within normal limits. The chest x-ray film (Ffgure 1) demonstrated bilateral interstitial infiltrates and a normalsized heart. The sputum specimen was unsatisfactory; a gram stain of a transtracheal aspirate revealed polymorphonuclear leukocytes and a few gram-negative rods. Therapy with gentamicin and nafcillin was begun. Over the ensuing 48 hours, the patient’s hypoxemia and the findings on the chest roentgenogram worsened. Bronchoscopy with transbronchial biopsy was performed on the third hospital day. Special stains for pneumocystis carinii. fungi and acid-fast bacilli were negative

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as were all cultures. The administration of sulfamethoxazole/trimethoprim [Bactrima DS 2 tablets every 6 hours) was begun for possible Pneumocystis infection. The transbronchial biopsy specimen demonstrated focal fibrosis and marked atelectasis. When ,on the sixth day the PaOs had decreased to 48 Torr with a fractional inspired oxygen (FtOs] of 0.40, an open lung biopsy of the lingula was performed. The biopsy specimens (Figure 2) demonstrated focal and diffuse areas of lymphocytic infiltration with some emphysematous changes and focal areas of fibrosis. Special stains were again negative for organisms, and cultures were sterile. Following surgery, the patient showed improvement with the only therapy being the completion of the two week course of sulfamethoxazole/trimethoprim. Acute and convalescent Legionnaires’ titers were less than I:32 and viral serology was unremarkable. At the time of discharge, the PaOs was 62 Torr on room air. Upon discharge the diagnosis was interstitial pneumonia of unknown etiology. Two months later, when the patient had no pulmonary symptoms, a follow-up chest film showed clearing of the infiltrates (Figure 3). At the time, melphalan and prednisone chemotherapy was restarted. Once again, two weeks following the second monthly course, the patient became symptomatic and was readmitted with increased shortness of breath, but no fever or sputum. The respiratory rate was again increased, but the remainder of the physical examination was unremarkable. Laboratory data on admission included a hemoglobin level of 7.4 g/106 ml: white blood cell count 2,566/mms with a normal differential; protein 5.4 g/l66 ml; albumin 2.8 g/l66 ml: and arterial blood gases on room air pH 7.47. Pa02 55 Torr, PcoZ 29 Torr.‘The chest film revealed recurrence of the interstitial infiltrates [Figure 4). Serum rheumatoid factor and antinuclear antibody were absent, serologic test for syphilis (VDRL) was negative and the serum complement level was normal. A gallium-67 scan of the lungs showed diffuse bilateral uptake. The patient was given only supplemental oxygen and bronchodilators. All cultures were negative. On follow-up three months later, he was asymptomatic and had no abnormalities

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Figure 4. Posteroanterior chest roentgenogram obtained on second admission shows recurrence of bilateral interstitial infiltrates.

on a chest roentgenogram [Figure 5). At this time, his forced vital capacity was 3.61 liters (91 per cent predicted], his forced expiratory volume in 1 second was 2.36 liters (77 per cent predicted) and his total lung capacity was 6.59 liters (100 per cent predicted). SPECIAL

STUDIES

The following studies of the patient’s peripheral blood and alveolar mononuclear cells were performed to examine the pathogenetic role of melphalan. They were performed approximately seven weeks following the last course of chemotherapy. Cell Preparation. Peripheral blood mononuclear cells were obtained from 10 ml of heparinized blood by the method of Boyum [ll]. More than 95 per cent of the isolated cells were mononuclear cells. Viability was 98 to 100 per cent by trypan blue exclusion. Fifty milliliters of pulmonary lavage fluid obtained from saline lavage at bronchoscopy were filtered through sterile gauze pads to remove strands of mucous. The remaining cells were washed three times with RPM1 1640 medium with a recovery of 3 X lo6 large round mononuclear cells which morphologically appeared to be macrophages. Cell Culture. Our culture system has been previously described in detail [12] and is summarized subsequently. The cells were dispensed by a Hamilton syringe into flat-bottom wells of microtiter culture plates. Each well contained 2 X lo5 peripheral blood mono-

Figure 5. Posteroanterior chest roentgenogram obtained approximately three months after the second admission and discontinuationof melphalan therapy shows nearly complete resolution of parenchymal disease.

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TABLE I

Suppressive Effect of Pulmonary Alveolar Mononuclear Cells On Peripheral Blood Mononuclear Cells Reactlvlty

Peripheral Mood Mofnhuclear Ceils ho.1 2x 2x 2x 2x 2x 0 l

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105 105 105 105 106

Puknonarr MonolwcIear cells (%I 0 1 5 10 20 100

3H-Thymbdlne Uptake at Various PHA Comentralions 0 799’ 322 339 259 313 72

cgw

I.5

. 5,112 567 434 361 366 86

36.171 35,157 29,346 24,639 18.872 189

Counts per minute.

nuclear cells in RPM1 1640, supplemented with 10 per cent heat-inactivated fetal calf serum, 1 per cent antibiotic-antimycotic and 1 per cent glutamine. To assess the influence of alveolar macrophages on peripheral blood mononuclear cells, varying numbers of pulmonary mononuclear cells were added to each well to give final macrophage percentages of 1,5.10,20, and 100 per cent. The final volume of each well was 0.2 ml. The T cell mitogen, phytohemagglutinin. was added in concentrations of 0.0. 0.15 and 1.5 pg/ml. The plates were incubated at 37C in a humidified 5 per cent carbon dioxide atmosphere for 68 hours. Measurement of DNA Synthesis. One microcurie of tritiated thymidine specific activity 3 mm3 was added to each well. Four hours later, the cultures were harvested onto glass fiber filters with multiple washes of distilled water with an automated sample harvester. Tritiated thymidine uptake was determined in a scintillation counter. The ability of melphalan itself to act as an antigen in the induction of periphera,l blood mononuclear cells proliferation was evaluated with a similar culture system. Cultures were performed in 10 per cent human serum and tritiated thymidine was added for 6 hours on the fifth day. RESULTS The function of the peripheral blood mononuclear cells, as assessed by their response to phytohemagglutinin, was suppressed by the pulmonary alveolar macrophages. As few as 1 per cent added pulmonary lavage cells elicited a tenfold decrease in the response of the peripheral blood monopuclear cells to a suboptimally stimulating concentration of phytohemagglutinin. At the higher concentration of mitogen, 20 per cent pulmonary cells produced a twofold suppression. Pulmonary mononuclear cells alone had no significant mitogen reactivity (Table I]. There was no evidence of antigen-induced proliferation in response to melphalan. A wide range of concentrations of this drug (0.001 to 100 pg/ml) failed to stimulate any incorporation of tritiated thymidine by the

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patient’s peripheral blood mononuclear cells. Although melphalan is a cytotoxic drug, the lower concentrations (0.001 to 0.01 pg/ml) did not significantly interfere witfi mitogen proliferation in cultures containing both agents. COMMENTS Melphalan is a phenylalanine derivative of nitrogen mustard and, like other alkylating agents, exerts its antineoplastic action by cross-linking DNA in rapidly proliferating cells. It is useful in the treatment of a number of neoplasms most notably multiple myeloma. Pulmonary infiltrates in the patient subjected to immunosuppression and receiving chemotherapy can present diagnostic difficulty. The differential diagnosis includes progression of the underlying disease; bacterial, fungal, viral and protozoa1 infections: and toxicity of the chemotherapeutic agent. Radiation pneumonitis and oxygen toxicity may also be a consideration. Pulmonary disease secondary to the use of antineoplastic drugs most commonly is manifested by diffuse bilateral interstitial infiltrates. It is frequently dose-related. Histologically, there are interstitial fibrosis and intraalveolar dysplasia. It is often irreversible (13.141. Busulfan was the first such agent described. With it, syndromes develop only after months to years of therapy [1,13]. Since then, other alkylating agents, cyclophosphamide [2], chlorambucil [6], BCNU [7.8] and the antibiotic, bleomycin [3.4], have been reported to produce similar clinical and pathologic responses. Methotrexate has been associated with the acute and subacute onset of respiratory illness. Microscopically, granulomas with multinucleated gian! cells are seen in addition to the typical interstitial fibrosis and alveolar dysplasia [5,13]. Procarbazine is associated with a hypersensitivity reaction, (151. Codling and Chakera [9] reported a case of pulmonary fibrosis after three months of daily melphalan therapy. The histologic picture was similar to that of other alkylating agents except for prominent intraalveolar giant cells and an interstitial plasma cell infiltration. The etiology of lung disease in their patient with multiple myeloma remains uncertain because he had also received cyclophosphamide for a week and had been given radiation therapy to the sternum and spine; in addition, there is a suggestion that the patient had intercurrent respiratory tract infection. Our case almost certainly represents pulmonary toxicity from melphalan. The patient had received no drug other than prednisone, and had twice experienced shortness of breath, arterial hypoxemia and bilateral interstitial lung infiltrates within two weeks of completing the second dose of monthly melphalan-predinisone therapy. In both instances, the symptoms and infiltrates cleared with the discontinuation of melphalan therapy.

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The pathologic response in this case was nonspecific, consisting predominantly of a marked interstitial lymphocytic infiltration with some areas of fibroblastic activity. Unlike the histology seen as a result of other alkylating agents there was no alveolar edema or proliferation of atypical type II pneumocytes. The time of biopsy should not totally explain this difference. Focal areas of atelectasis and emphysema present in this tissue are thought to be unrelated to the acute process. The primary treatment for drug-induced lung damage has been to withhold the chemotherapeutic agent. Reversibility is a function of the degree of fibrosis and may or may not be dose-related [3,14]. Steroids have been used, but no controlled studies have evaluated their effect. In this patient, the infiltrates twice resolved within three months of discontinuing the drug. The mechanism of lung toxicity is not clear. Drug induced pulmonary reactions have been thought to be the result of either a hypersensitivity reaction or a direct toxic effect [13,14]. The time course in this patient was not immediate, but short-six weeks following initiation of therapy on each occasion-and occurred with a low dosage of the agent. Although the onset of symptoms followed the second exposure to the drug on both occasions, there was a lack of eosinophils in the tissue and other stigmata associated with allergic reaction. The development of pulmonary toxicity following the use of chemotherapeutic agents could possibly be secondary to dysfunction of alveolar macrophages. Recent

ET AL.

studies in rats [IS]and dogs [l7] have documented marked suppressive activity of alveolar cells on peripheral lymphocytes. These studies suggest that hypersensitivity reactions to inhaled antigens may be normally inhibited by pulmonary macrophages. Accordingly, impaired suppressor activity might enhance reactivity to environmental antigens. In contrast to the macrophages of the previous studies in human subjects [18,19], the bronchial lavage cells from our patient markedly suppressed his peripheral blood response to phytohemagglutinin. This finding may indicate improved macrophage suppressor function associated with clearing of his lung disease. Since the study was performed seven weeks after he received his last dose of melphalan, we may have failed to detect a transient drug-induced impairment of suppressor activity. Alternatively, the suppressor activity may be an abnormal finding which may or may not relate to his drug-associated pulmonary disease. Melphalan by itself was not stimulatory to the patient’s peripheral blood lymphocytes. Although the pathogenesis of the melphalan-induced lung disease remains unclear, in our patient interstitial lymphocytic infiltrates developed twice and cleared with discontinuation of the drug. Further studies of such patients’ alveolar macrophages and peripheral blood lymphocytes are warranted. Meanwhile, physicians should be aware of this new complication of melphalan therapy.

REFERENCES 1. Burns WA, McFarland

W, Mathews MJ: Busulfan induced pulmonary disease. Am Rev Respir Dis 1970; 101: 40% 413. 2. Pate1 AR, Shah PC, Rhee JL, et al.: Cyclophosphamide therapv and interstitial uulmonarv fibrosis. Cancer 1976: 38: 1542-1549. 3. Haas CD, Coltman CA, Gottlieb JA, et al.: Phase II evaluation of bleomycin. Cancer 1976; 38: 8-12. 4. Blum RH, Carter SK, Agre K: A clinical review of bleomytin-A new antineoplastic agent. Cancer 1973; 31:903914. 5. Sostman HD, Matthay RA, Putman CE, et al.: Methotrexate-induced pneumonitis. Medicine (Baltimore] 1976; 55: 371-378. 6. Cole SR, Myers TJ, Klatsky AU: Pulmonary disease with chlorambucil theraov. Cancer 1978: 41: 455-459. 7. Ho10 e PY, Jenkins Gg, Greenberg SD: Pulmonary toxicity in fronpterm administration of BCNU. Cancer Treat Reo 1976; & 1691-1693. 8. Duraut JR, Norgard MJ, Murad TM, et al.: Pulmonary toxicity associated with bischloroethylnitrosourea (BCNU). Ann Intern Med 1979: 90: 191-194. 9. Codling BW, Chakera TMH: Pulmpnary fibrosis following therapy with melphalan for multiple mveloma. 1 Clin Pathdl-1972; 25: 668-673. _ ” . 10. Dickman PS, Taetle R, Feldman PS: Pulmonary histopathologic changes associated with melphalan therapy [abstract). In: Proceedings of 74th Annual Meeting, American Association of Pathologists, Toronto, Canada, 1977; 336-337.

11. Boyum A: Isolation of mononuclear

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cells and-granulocytes from human blood. Isolation of mononuclear cells by one centrifunation and sedimentation at 1 R’. Stand 1 ’ Clin _ Lab Invest l&X$97 [suppl]: 77-89. Michalski JP, McCombs C: Decreased lymphocyte’reactivity to a suboptimal concentration of phytohemagglutinin in sjijgren’s syndrome. Arthritis Rheum 1977; 20: 851-858. Rosenow EC: The spectrum of drug-induced pulmonary disease. Ann Intern Med 1972: 77: 977-991. Green MR: Pulmonary toxicity of antineoplastic agents. West 1 Med 127: 1977: 292-298. Jones SE, Moore M, Blank N, et al.: Hypersensitivity to procarbazine lmatulanel manifested bv fever and oleuro* pulmonary‘reaction. cancer 1972; 26: 498-500. Holt PG: Inhibitory activity of unstimulated alveolar macrophages on T-lymphocyte blastogenic response. Am Rev Respir Dis 1978; 118: 791-795. Ansfield MJ, Kaltreider HB. Caldwell JL, Herskowitz FN: Hyporesponsiveness of canine bronchoalveolar lymphocytes to mitogens: inhibition of lymphocyte proliferation by alveolar macrophages. J Immunol1979; 122: 542-548. Laughter AH, Martin RR, Twomey JJ: Lymphoproliferative responses to antigens mediated by human pulmonary alveolar macrophages. J Lab Clin Med 1977; 89: 13261332. Dani& RP, Dauber JH, Altose MD, Roslands DT Jr. Gorenberg DJ: Lymphocyte studies in asymptomatic cigarette smokers. A comparison between lung and peripheral blood. Am Rev Respir Dis 1977: 118: 997-1005.

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